Using the fan, heater

[signs]

Sorry if this sounds like a noob question, but will using the fan and heater use up more petrol compared to the fan being turned off. What about compared to the air con instead of heater being turned on?

[NJBob]

No. Only the A/C taxes the engine as the compressor has a belt that literally runs off the engine and will drop your MPG about 2-3.....equal to driving fast with the A/C off and the windows open.

[ToddR]

FYI
Running the heat on the "Defrost" setting will run the A/C compressor to remove moisture from the heated air. This will cause the same drop in fuel economy as running the A/C to cool the car. If you do a search here you will find a more detailed explanation.

[otterhere]

Which brings me back the one of the things I MOST hate about this car, which is that you can't drive with the ding-dang windows down unless you want banging in your ears; this is crazy car design!!! It's hot from April through October here, so there goes my gas mileage for MOST of the year (I almost never ran a/c in the Swift; windows were always down and life was good). Honestly, I'm not sure I can last long with this car... Yes, I know you can "do things" and "add things" to mitigate that; I paid big bucks (relatively speaking) and would like not to have to remake it to make it work...

[detroiter]

Ahh your refferring to the infamous "Sonic boom" effect. If one window is completely own, as long as the other one is slightly lowered a bit...the effect isn't really there. I really do plan on getting some of the weather guards for the windows, it's really bad how you can't even crack the window if it's raining since the water will drip right on in.

[BailOut]

Yes, using the heater and fan does use more fuel. The hit is not nearly as large as with a/c but it is there.

The fan requires electricity and the alternator puts more of a load on the engine to produce it. The engine also produces only so much waste heat that makes it into the cooling system, and it often experiences drops in the coolant temperature which causes the ECU to cause the engine to burn more fuel (by running richer and/or at a higher RPM). This means that sometimes you're pulling heat from the system that the engine cannot afford to lose, but other times it is happy to dump excess heat.

Sometimes you simply need to use the heat. One should never allow themselves to get too cold in the car. However, like any other use of energy it is best kept to a minimum. Wear a coat and hat and gloves and you'll find you don't need to use the heat nearly as often. :smile:

[Yar Is Word]

http://www.yarisworld.com/forums/search.php?searchid=433412

[otterhere]

http://www.yarisworld.com/forums/search.php?searchid=433412

Something's very wrong with the design if you have to ADD parts to make things work properly. Sloppy and disappointing coming from Toyota, IMO.

:mad:

Now back to being positive!

:biggrin:

[colb]

Yes, using the heater and fan does use more fuel. The hit is not nearly as large as with a/c but it is there.

The fan requires electricity and the alternator puts more of a load on the engine to produce it. The engine also produces only so much waste heat that makes it into the cooling system, and it often experiences drops in the coolant temperature which causes the ECU to cause the engine to burn more fuel (by running richer and/or at a higher RPM). This means that sometimes you're pulling heat from the system that the engine cannot afford to lose, but other times it is happy to dump excess heat.

Sometimes you simply need to use the heat. One should never allow themselves to get too cold in the car. However, like any other use of energy it is best kept to a minimum. Wear a coat and hat and gloves and you'll find you don't need to use the heat nearly as often. :smile:

I think I recall that cold enrichment does not occur above 135F or so on most cars... it's safe to say that your heater will never pump enough heat to get the car into the cold enrichment temperature zone under normal operating conditions. (Actually, I have had this problem in my '85 MR2 when temperatures were below 15F while driving at highway speeds, but that involves problems the Yaris does not have.) The motor produces at least as much waste heat as it does useful work, and even for a tiny Yaris it takes a LOT of energy to push around a 2500+lb metal room on wheels. Using the A/C is using energy you would not otherwise have wasted. Using the heater is using energy that you were throwing out the radiator already, and if the motor is being cooled into its cold-enrichment zone then your radiator has become extraneous.

The fan takes up close to zero power, especially at the low settings. It's insignificant compared to the headlights, much less the A/C.

[BailOut]

colb,

You bring up a good point about the cold enrichment occurrence. I see it rather frequently since I can stay in DFCO for miles on my trip home for work each day and the temperatures, especially at altitude, often dip below 0F. Folks that live in warmer, flatter climes will likely never see it, though.

While the blower does not take a huge amount of energy no energy is free, and anything it uses does indeed place a load on the engine. The engine is powered by fuel, ergo any additional electrical load increases fuel consumption.

[colb]

Ah. You certainly can get into situations where the engine gets down below operating temperature then. That is a pretty nasty situation for engine longevity too, if the motor and oil gets cold and is being driven by the car's weight going down a hill. I would coast out of gear and let the car idle for the sake of prolonging motor life (or, if it were me, I might turn the motor off). You're wasting so little gas during idle that you probably wouldn't notice the difference between coasting in gear and in idle.

Which brings me to my next point. The fan certainly does use power, but as usual we need to use our good engineering judgment and ask "how much?" In this case it is at least a couple of orders of magnitude less than the power required to move the car at any speed. Does it use energy - yes. Will it ever use enough energy for you to notice with any common form of measurement, especially gas mileage - no. And in city driving when the car is warm, it's often a toss up between turning the heater and fan on and turning the big giant radiator fan on, which will probably use ten times as much power as the cabin fan. You probably don't have that problem though :D

[NJBob]

FYI
Running the heat on the "Defrost" setting will run the A/C compressor to remove moisture from the heated air. This will cause the same drop in fuel economy as running the A/C to cool the car. If you do a search here you will find a more detailed explanation.

I don't think so. You have to punch the A/C button to do that.:iono:

[BailOut]

I don't think so. You have to punch the A/C button to do that.:iono:

No, you don't, and that's the whole gripe that everyone has with it. Whether or not you have the a/c button depressed, if you use either of the dedicated defrost settings the a/c will run along with the heater, simply for the dehumidifying effect.

[nemelek]

Does anyone actually have any proof of the 2-3 mpg loss using the A/C. Last summer I got better mpg using the A/C then I do now with the winter fuel blend. Last summer while climbing a 10 mile long 7% grade at 70 mph I experimented with the A/C. I noticed no power loss while turning it on or no power gain after turning it off.

[NJBob]

No, you don't, and that's the whole gripe that everyone has with it. Whether or not you have the a/c button depressed, if you use either of the dedicated defrost settings the a/c will run along with the heater, simply for the dehumidifying effect.

My bad...I guess. I can't find anything in the owner's manual but when I have the settings on defrost I can hit the A/C button and feel the compressor turn on. When I hit it again, it, of course turns off.

I'll have to see but I understand what you're saying. My Neon had the constant A/C to defrost which worked great but wasn't always necessary to clear the windows...not to mention it bumping up the rpm's and burning more fuel as consequence.

[NJBob]

Which brings me back the one of the things I MOST hate about this car, which is that you can't drive with the ding-dang windows down unless you want banging in your ears; this is crazy car design!!! It's hot from April through October here, so there goes my gas mileage for MOST of the year (I almost never ran a/c in the Swift; windows were always down and life was good). Honestly, I'm not sure I can last long with this car... Yes, I know you can "do things" and "add things" to mitigate that; I paid big bucks (relatively speaking) and would like not to have to remake it to make it work...

I agree that you shouldn't have to FIX something to remove the bludgening effect from high speed driving with the windows down. I added the Weathertech Window deflectors which DID ease up the pounding. However if you're driving at 60+ mpg you may as well turn on the A/C. If you have no A/C or prefer not to use it then I'd look into another car and test that bad boy at Hiway speed. :smile:

[BailOut]

Does anyone actually have any proof of the 2-3 mpg loss using the A/C. Last summer I got better mpg using the A/C then I do now with the winter fuel blend. Last summer while climbing a 10 mile long 7% grade at 70 mph I experimented with the A/C. I noticed no power loss while turning it on or no power gain after turning it off.

nemelek,

Anyone with a ScanGauge can see this in real-time. Within a seconds of turning the a/c system on a noticeable MPG hit occurs. On that grade you likely did not notice a power change because the engine was already at 90%+ load. When that happens I have noticed that the ECU does not allow the a/c compressor to clutch much, if at all.

[1stToyota]

Sorry if this sounds like a noob question, but will using the fan and heater use up more petrol compared to the fan being turned off. What about compared to the air con instead of heater being turned on?

If it does use extra fuel to run the heater, not enough to worry about. If they tell you that it'll put more load on the charging system and that'll somehow cause you to burn extra fuel...then :bellyroll: ...don't run your headlights or wipers, they'll give a big hit to the MPG :wink:

[BailOut]

If it does use extra fuel to run the heater, not enough to worry about. If they tell you that it'll put more load on the charging system and that'll somehow cause you to burn extra fuel...then :bellyroll: ...don't run your headlights or wipers, they'll give a big hit to the MPG :wink:

Headlights and wipers are not optional. Using the heating system often is.

[UTVitz]

Click and Clack on NPR's CarTalk have had this question asked of them. Technically the answer is yes, but, in all reality it's not enough to even give a thought too. Your comfort and clarity of defogged windows is more important. Now I often don't run the fan in the interest of making the blower motor last a long, long, time. Since I never seem to get rid of my cars this has so far worked on a very old Jeep and Miata. How you drive the car is by far the best way to get good gas mileage.

[blktiger60]

Something's very wrong with the design if you have to ADD parts to make things work properly. Sloppy and disappointing coming from Toyota, IMO.

:mad:

Now back to being positive!

:biggrin:

The Yaris isn't the only vehicle out there that does this.
The Dodge Calibre does it too, that's one I know of for sure.

[Spades]

i almost always run with my heater set to floor/defrost because on the sedan i have, it wont kick the A/C compressor on. if you don't belive the compressor doesnt kick on, just listen to your engine, or if you have a tach, watch your RPM's, then turn the defrost on.
it kicks the a/c on, dropping your milage.

now, in the summer, I have tried it, I get about 2+mpg better running one window on my 4 door sedan down, than running with AC on. I am guessing that isnt as significant of drag increase as all windows down, because most studies show that all windows down is just as painful on economy as windows up and AC.

but, by the theory of "the electricity consumption of the heater should on paper lower milage", then i shouldnt be able to pull the milage i do with over 1500 watts of stereo gear running,lol.


EDIT: and as far as vehicles having the annoying booming sound with all or most windows down, and the AC kicking on when defrost is on, go drive more cars. been working on cars for a living for about 10 years now, and, most of them have these issues. alot of cars out there dont even have a windshield defrost that doesnt turn the AC on...its all or nothing,lol.

[1stToyota]

Headlights and wipers are not optional. Using the heating system often is.

Using the headlights and wipers are going to take a hit on the MPG?! :bellyroll:

[otterhere]

"...as far as vehicles having the annoying booming sound with all or most windows down...been working on cars for a living for about 10 years now, and, most of them have these issues..."

I could name ONE car* that didn't have that issue, but I think everyone's sick of hearing about it...


*2000 Suzuki Swift hatchback

[BailOut]

Using the headlights and wipers are going to take a hit on the MPG?! :bellyroll:

Yes. Energy is not free. Anything at all in or on the car that requires electricity gets it from the alternator, or from the battery which is replenished by the alternator. Any load whatsoever on the alternator is in turn a load on the engine.

Is it a huge hit? No. But it is a hit.

[1stToyota]

Yes. Energy is not free. Anything at all in or on the car that requires electricity gets it from the alternator, or from the battery which is replenished by the alternator. Any load whatsoever on the alternator is in turn a load on the engine.

Is it a huge hit? No. But it is a hit.

It's a load on the electrical system. The serpentine belt, rotating mass, etc are a load on the engine...using the turn signals isn't a hit on fuel economy. Besides, I never use the wipers...I just "plan ahead" and avoid those rain clouds. :rolleyes:

[otterhere]

"Besides, I never use the wipers...I just "plan ahead" and avoid those rain clouds."


You're being facetious... Right?

:wink:

[1stToyota]

"Besides, I never use the wipers...I just "plan ahead" and avoid those rain clouds."


You're being facetious... Right?

:wink:

It's a bailout joke around here, based on his theory about dodging. If he can avoid accidents by dodging deer that spring onto the road by planning ahead for it, I can dodge the raindrops. :wink:

[otterhere]

I actually use my wipers very sparingly; don't ask me why! I guess I think I'm saving wiper blade material or something. When it's not raining too hard, I just use my intermittant, and I actually turn them OFF at stoplights. Watch me wear out the switch.

[1stToyota]

I actually use my wipers very sparingly; don't ask me why! I guess I think I'm saving wiper blade material or something. When it's not raining too hard, I just use my intermittant, and I actually turn them OFF at stoplights. Watch me wear out the switch.

I use lots of rain-x on this Yaris. Never had a car before that had a fixed intermittant wiper. If it's a light rain the rain-x saves me a lot on turning the switch on and off.

[BailOut]

It's a bailout joke around here, based on his theory about dodging. If he can avoid accidents by dodging deer that spring onto the road by planning ahead for it, I can dodge the raindrops. :wink:
I guess we have a 1stToyota joke now, too. Something about free energy and perpetual motion serpentine belts on the Yaris. :rolleyes:

[1stToyota]

I guess we have a 1stToyota joke now, too. Something about free energy and perpetual motion serpentine belts on the Yaris. :rolleyes:

Are we pretending that belt driven accessories don't rob hp but using the turn signals and washers do? :tongue:

Guess the sale of underdrive pulleys will be down now and Toyota will go back to belt driven power steering pumps and cooling fans... and they'll switch back to 6v systems so they'll take a lot less hits on the MPG :thumbdown:

And energy isn't free...takes a voltage generator (alternator) and a reference source (battery), and of course a regulator/PCM to adjust for electrical loads. Thinking that using the radio will cause worse fuel economy is drastic and silly. And the reason the A/C uses more fuel is because it takes more force to operate the compressor with the a/c clutch engaged, vs a free-wheeling bearing, has nothing to do with current load on the alternator.

[toast]

If you want to make 1000% sure the compressor won't come on in the winter with the defrost running, pull the compressor fuse or pull the plug off the compressor. When it get's hot out, reinstall the fuse. If you're really hard core and want to make sure the neighbor doesn't borrow your car and run the a/c, snip the electrical wires to the compressor. With that said, come on folks the car get's great mileage even with using some comforts. Live a little. Oh and the booming window thing. I've found it's much better if both windows are open as opposed to just one. But I suppose that kills the aerodynamics so I guess I can't win. I will find my rock and go back under it now.

[colb]

I suppose a Yaris forum, if anywhere, would be the place where you'd expect to find people who can't get it through their heads that saving energy doesn't matter if you're not saving enough to notice.

Getting a tenth of a percent better gas mileage (like driving without DRLs during the day, or the fan on full blast, or using windshield wipers in the rain) just doesn't matter. It will not affect your wallet. It will not affect CO2 emissions. Does it really count as saving energy if there's no possible way you can ever notice it? Nope, not in the real world. If everybody saved a tenth of a percent of gas mileage, would it reduce our dependence on foreign oil? Nope.

This is often called "good engineering judgment" or alternatively "common sense."

[voodoo22]

I suppose a Yaris forum, if anywhere, would be the place where you'd expect to find people who can't get it through their heads that saving energy doesn't matter if you're not saving enough to notice.

Getting a tenth of a percent better gas mileage (like driving without DRLs during the day, or the fan on full blast, or using windshield wipers in the rain) just doesn't matter. It will not affect your wallet. It will not affect CO2 emissions. Does it really count as saving energy if there's no possible way you can ever notice it? Nope, not in the real world. If everybody saved a tenth of a percent of gas mileage, would it reduce our dependence on foreign oil? Nope.

This is often called "good engineering judgment" or alternatively "common sense."

Following this logic, will everyone please give me a tenth of a percent of their savings and salary?:wink:

[BailOut]

I suppose a Yaris forum, if anywhere, would be the place where you'd expect to find people who can't get it through their heads that saving energy doesn't matter if you're not saving enough to notice.

Getting a tenth of a percent better gas mileage (like driving without DRLs during the day, or the fan on full blast, or using windshield wipers in the rain) just doesn't matter. It will not affect your wallet. It will not affect CO2 emissions. Does it really count as saving energy if there's no possible way you can ever notice it? Nope, not in the real world. If everybody saved a tenth of a percent of gas mileage, would it reduce our dependence on foreign oil? Nope.

This is often called "good engineering judgment" or alternatively "common sense."

You completely missed out on the first tenet of engineering by failing to focus on the original problem. The original question was whether using these things uses more fuel, which it indeed does. The question was not whether it was worth worrying about or not.

Some people may not care but hypermilers strive to stretch every gallon of gasoline for all it is worth. 0.1% is a totally arbitrary number and may not sound like much but when you add it up over the course of your lifetime it becomes an easily trackable amount. For example, if you average 32 MPG then you use 0.03125 gallons per mile. If you drive 15,000 miles per year it requires 469 gallons of fuel. If you maintain this pattern from age 16 to age 75 it requires 27,656 gallons of fuel. 0.1% of that is 28 gallons, or 3 fill ups.

[1stToyota]

You completely missed out on the first tenet of engineering by failing to focus on the original problem. The original question was whether using these things uses more fuel, which it indeed does. The question was not whether it was worth worrying about or not.

So when you use that turn signal the alternator instructs the fuel pump to give the engine some more fuel, because of the electrical load? :bellyroll:


Some people may not care but hypermilers strive to stretch every gallon of gasoline for all it is worth. 0.1% is a totally arbitrary number and may not sound like much but when you add it up over the course of your lifetime it becomes an easily trackable amount. For example, if you average 32 MPG then you use 0.03125 gallons per mile. If you drive 15,000 miles per year it requires 469 gallons of fuel. If you maintain this pattern from age 16 to age 75 it requires 27,656 gallons of fuel. 0.1% of that is 28 gallons, or 3 fill ups.

Really? I don't know how many drops of fuel this will save per tank full, but what if I always remember to go to the bathroom before I get into the car...carrying that extra *payload* around has to give some kind of hit on the MPGs. Let's figure that I always remember to go before I go, for the next 30 years... :rolleyes:

[BailOut]

So when you use that turn signal the alternator instructs the fuel pump to give the engine some more fuel, because of the electrical load? :bellyroll:
How many ways do you intend to ask the same question? No matter how many times you ask it or how many emotes you use or how much you wish it wasn't so the truth does not change. Energy is not free except in your imaginary world of serpentine belts in perpetual motion.


Really? I don't know how many drops of fuel this will save per tank full, but what if I always remember to go to the bathroom before I get into the car...carrying that extra *payload* around has to give some kind of hit on the MPGs. Let's figure that I always remember to go before I go, for the next 30 years... :rolleyes:
That's not a bad idea at all. In fact it's the only sound idea I've ever seen you come up with. Though I think most people already do this as no one likes to travel while holding it.


It has become quite clear over the last week or so that you are not in this thread to learn or to contribute, but only to taunt others. I encourage you to find more effective ways to spend your time and energy.

[smacky]

So when you use that turn signal the alternator instructs the fuel pump to give the engine some more fuel, because of the electrical load? :bellyroll:




Really? I don't know how many drops of fuel this will save per tank full, but what if I always remember to go to the bathroom before I get into the car...carrying that extra *payload* around has to give some kind of hit on the MPGs. Let's figure that I always remember to go before I go, for the next 30 years... :rolleyes:

I've yet to see any positive contribution you've made to any discussion you've participated in. It just seems like you look for any post by BailOut and you contradict it. How about you just stop posting on the fuel economy forum and any time BailOut says anything, we all just assume you've found some terribly witty way to disagree with him. Just go away.

[colb]

You completely missed out on the first tenet of engineering by failing to focus on the original problem. The original question was whether using these things uses more fuel, which it indeed does. The question was not whether it was worth worrying about or not.

Some people may not care but hypermilers strive to stretch every gallon of gasoline for all it is worth. 0.1% is a totally arbitrary number and may not sound like much but when you add it up over the course of your lifetime it becomes an easily trackable amount. For example, if you average 32 MPG then you use 0.03125 gallons per mile. If you drive 15,000 miles per year it requires 469 gallons of fuel. If you maintain this pattern from age 16 to age 75 it requires 27,656 gallons of fuel. 0.1% of that is 28 gallons, or 3 fill ups.

No, the original question was along the lines of can you save fuel by not using the fan or heater. You say it wastes fuel. I say prove it. The difference is many times less than the margin of variability from tank to tank.
What is commonly referred to as "good engineering judgment" is focusing on reality, not theory. Theory says the fan uses gasoline, but reality will not back up that statement when the fan uses 10 watts and the car takes 10kW to cruise, while other random factors (humidity, temperature, wind, rain, payload, traffic) influencing mileage probably make up ten to a hundred times as much variability as you save by leaving the fan off.

Plus, you really just recommended that by not using the fan you can save 28 gallons of gas over 60 years.

[1stToyota]

How many ways do you intend to ask the same question? No matter how many times you ask it or how many emotes you use or how much you wish it wasn't so the truth does not change. Energy is not free except in your imaginary world of serpentine belts in perpetual motion.

You're the numbers geek, so prove it. Saying that energy isn't free and that using headights or the wipers will somehow cause the engine to burn more fuel doesn't mean a thing unless you've got the numbers to prove it. Show me where running the fan on speed 3 burns more fuel than speed 2.



That's not a bad idea at all. In fact it's the only sound idea I've ever seen you come up with. Though I think most people already do this as no one likes to travel while holding it.

Yeah, 30-40 years from now I might have a whole extra $ or 2 to go crazy with.


It has become quite clear over the last week or so that you are not in this thread to learn or to contribute, but only to taunt others. I encourage you to find more effective ways to spend your time and energy.

NO, I'm here to see the proof behind your honking the horn just stole a little bit of fuel from the gas tank theories.

Maybe it's because you think using the A/C burns fuel because the clutch circuit is hot, but that's not the reason. It's the extra LOAD on the engine because an engaged compressor is harder to spin than a free-wheeling bearing (like when clutch isn't engaged).

[1stToyota]

I've yet to see any positive contribution you've made to any discussion you've participated in. It just seems like you look for any post by BailOut and you contradict it. How about you just stop posting on the fuel economy forum and any time BailOut says anything, we all just assume you've found some terribly witty way to disagree with him. Just go away.

I'm sorry if I stepped on toes but I need proof before I'll believe that using the wipers will cause an engine to burn more fuel.

Yes, a belt driven fan burns fuel, a defective fan clutch burns fuel, and belt driven P/S pump burns fuel, but an electric fan and P/S pump burns fuel? I haven't seen proof, just theories that it does.

[otterhere]

I'm sorry if I stepped on toes.


You made Smacky mad, girlfriend! Rude Smacky. Must we smack you, Smacky?:laugh:

[detroiter]

Whatever happened to just driving the car and enjoying it? There's such thing as hypermiling but geez, give me a break.

[otterhere]

Whatever happened to just driving the car and enjoying it? There's such thing as hypermiling but geez, give me a break.

Amen to that; I tried "hypermiling" for one day and had a headache at the end of it. If this car isn't fuel-efficient without breaking your back to achieve it, then it's not fuel-efficient. :bs:

[1stToyota]

Amen to that; I tried "hypermiling" for one day and had a headache at the end of it. If this car isn't fuel-efficient without breaking your back to achieve it, then it's not fuel-efficient. :bs:

I also "hypermiled" for 1 day and I've seen a major improvement ever since; I sold a 6.0 GTO and bought a 1.5 Yaris :clap:

[Rick]

I can think of only two sources of energy for a Yaris. The driver and the gasoline.
You turn the steering wheel, push the pedals, flip the switches, etc. ALL other energy dissipated (heat, light, motion, etc.) ultimately comes from burning gasoline. The battery is an imperfect energy storage device. More than you take from it must be put back by burning gasoline. What do you think isn't proven already??

BailOut is right ...... Those who claim wiper and fan energy usage is very small are right..... Those who think energy is entering the system from something other than driver and gasoline are wrong.

Conserve that tiny amount of energy if you like, Ignore it if you like.

Move on.

[1stToyota]

Not sure if that was based on facts or opinion. Any documented proof around here about running the fan speed on low will burn X amount of fuel, while running fan speed at a higher setting will cause the engine to use more fuel?

[BailOut]

I wasn't going to do this as I have little patience for your overall attitude but I got bored on the drive home today and played around a bit.

What I found not only supports what we have been telling you over and over and over but also shows that the energy cycle is more impacting than any of us thought.

This is detectable even while hill climbing but it is easier on flat ground or on a decline unless you have a very steady throttle foot. All measurements were gained using a ScanGauge II. Its voltage measurement only goes to one decimal place so the measurements are rough but solid.

At "rest" and with the engine running the electrical system sits at 14.1 volts. Since my DRL was on turning on the headlights doesn't produce much of a difference by itself, but combining that with the stock radio on a volume setting of about 20 and using the blinkers was enough to knock the measurable voltage down to 14.0V. After about 2 seconds of this the voltage goes up to 14.2V for a while, which indicates that the alternator is clutching and producing a higher output. Once done the voltage drops back to 14.1V and will stay there if you stop the additional drains, otherwise it will repeat the cycle of dropping to 14.0V and charging back to 14.2V. Using the high beams can produce this effect almost immediately as it is a rather large draw on the electrical system, though not nearly as much as most aftermarket stereo setups, and the alternator clutches for longer to deal with it.

So I got to wondering how much this minor clutching of the alternator was dragging on the engine. I wasn't sure if it would be measurable or not. So I brought up the "load" meter on the SGII. It reads 40 at its lowest and 100 at its highest. Every single time the alternator clutched and produced 14.2V the load reading went up by 1. As soon as the alternator calmed down it went back to 1 lower number. The instant MPG display also drops 1-2% during this time.

These measurements mean that the effect of minor electrical drains in the Yaris isn't 0.1% as was arbitrarily suggested, but is more like 1.5-2%! It will be even more under heavy, constant loads from things like large sound systems, producing even more of a fuel economy drain.

So, there you have it. You wanted numbers and documentation, and I just gave you both. Anyone with an SGII can verify my findings.

[colb]

So your gas mileage dropped by 1 to 2% for "about 2 seconds" when you turn on the radio? How much do you lose in steady state?? And how fast were you going?

Also, alternators don't have clutches -- you are opening and closing loads in the electrical system and the voltage regulator is making up for it.

[BailOut]

So your gas mileage dropped by 1 to 2% for "about 2 seconds" when you turn on the radio? How much do you lose in steady state?? And how fast were you going?

Also, alternators don't have clutches -- you are opening and closing loads in the electrical system and the voltage regulator is making up for it.

I know the alternator doesn't actually clutch but that's the easiest way to explain a load on it to most of the readers here. If you get too technical, like explaining that energy isn't free, it seems to confuse some people. :wink:

No, the mileage doesn't drop for just 2 seconds (unless you immediately stop the draw, which I did several times), but that seems to be the minimum load adjustment time for the alternator. If you leave equipment running the lower MPG and higher load state remains steady, or at least fluctuates as the voltage bounces between 14.0V and 14.2V.

My speed was 45-50 MPH.

[Altitude]

Just think of it like this - the regulator increases the current to the electro-magnetic rotor based upon the demands of your electical system and this in turn increases the attractive magnetic force, making the rotor want to 'stick' to the stators even more. This increase in force makes the alternator harder to spin - ergo more load on your engine.

Think of the force it takes to remove a rare earth magnet from your refrigerator versus one of those cheap 'carry-out restaurant' magnets and you'll get the idea.

[yaris-me]

I wasn't going to do this as I have little patience for your overall attitude but I got bored on the drive home today and played around a bit.

What I found not only supports what we have been telling you over and over and over but also shows that the energy cycle is more impacting than any of us thought.

This is detectable even while hill climbing but it is easier on flat ground or on a decline unless you have a very steady throttle foot. All measurements were gained using a ScanGauge II. Its voltage measurement only goes to one decimal place so the measurements are rough but solid.

At "rest" and with the engine running the electrical system sits at 14.1 volts. Since my DRL was on turning on the headlights doesn't produce much of a difference by itself, but combining that with the stock radio on a volume setting of about 20 and using the blinkers was enough to knock the measurable voltage down to 14.0V. After about 2 seconds of this the voltage goes up to 14.2V for a while, which indicates that the alternator is clutching and producing a higher output. Once done the voltage drops back to 14.1V and will stay there if you stop the additional drains, otherwise it will repeat the cycle of dropping to 14.0V and charging back to 14.2V. Using the high beams can produce this effect almost immediately as it is a rather large draw on the electrical system, though not nearly as much as most aftermarket stereo setups, and the alternator clutches for longer to deal with it.

So I got to wondering how much this minor clutching of the alternator was dragging on the engine. I wasn't sure if it would be measurable or not. So I brought up the "load" meter on the SGII. It reads 40 at its lowest and 100 at its highest. Every single time the alternator clutched and produced 14.2V the load reading went up by 1. As soon as the alternator calmed down it went back to 1 lower number. The instant MPG display also drops 1-2% during this time.

These measurements mean that the effect of minor electrical drains in the Yaris isn't 0.1% as was arbitrarily suggested, but is more like 1.5-2%! It will be even more under heavy, constant loads from things like large sound systems, producing even more of a fuel economy drain.

So, there you have it. You wanted numbers and documentation, and I just gave you both. Anyone with an SGII can verify my findings.



:w00t: Very smart! :w00t:

[1stToyota]

I wasn't going to do this as I have little patience for your overall attitude but I got bored on the drive home today and played around a bit.

What I found not only supports what we have been telling you over and over and over but also shows that the energy cycle is more impacting than any of us thought.

This is detectable even while hill climbing but it is easier on flat ground or on a decline unless you have a very steady throttle foot. All measurements were gained using a ScanGauge II. Its voltage measurement only goes to one decimal place so the measurements are rough but solid.

At "rest" and with the engine running the electrical system sits at 14.1 volts. Since my DRL was on turning on the headlights doesn't produce much of a difference by itself, but combining that with the stock radio on a volume setting of about 20 and using the blinkers was enough to knock the measurable voltage down to 14.0V. After about 2 seconds of this the voltage goes up to 14.2V for a while, which indicates that the alternator is clutching and producing a higher output. Once done the voltage drops back to 14.1V and will stay there if you stop the additional drains, otherwise it will repeat the cycle of dropping to 14.0V and charging back to 14.2V. Using the high beams can produce this effect almost immediately as it is a rather large draw on the electrical system, though not nearly as much as most aftermarket stereo setups, and the alternator clutches for longer to deal with it.

So I got to wondering how much this minor clutching of the alternator was dragging on the engine. I wasn't sure if it would be measurable or not. So I brought up the "load" meter on the SGII. It reads 40 at its lowest and 100 at its highest. Every single time the alternator clutched and produced 14.2V the load reading went up by 1. As soon as the alternator calmed down it went back to 1 lower number. The instant MPG display also drops 1-2% during this time.

These measurements mean that the effect of minor electrical drains in the Yaris isn't 0.1% as was arbitrarily suggested, but is more like 1.5-2%! It will be even more under heavy, constant loads from things like large sound systems, producing even more of a fuel economy drain.

So, there you have it. You wanted numbers and documentation, and I just gave you both. Anyone with an SGII can verify my findings.

I wasn't going to use one of your quotes, but I gues I will.

As best as I can remember, and adjusted for current topic...

"I need mileage logs for 3 tanks, using the radio, and 3 logs without the use of the radio, or your findings are meaningless" :wink:

You can do that if you like, but I've got better things to worry about than saving a few cents per year, as in not using the blower for the next 60 years. :rolleyes:

[BailOut]

I wasn't going to use one of your quotes, but I gues I will.

As best as I can remember, and adjusted for current topic...

"I need mileage logs for 3 tanks, using the radio, and 3 logs without the use of the radio, or your findings are meaningless" :wink:

You can do that if you like, but I've got better things to worry about than saving a few cents per year, as in not using the blower for the next 60 years. :rolleyes:

*sigh* You... just... don't... get it.

You cannot get 3 tanks of data without using the headlights or blinkers (I know some people never use their blinkers but I always do) so the usual testing method cannot apply. Nor can you ride down the road with the hood up and with a stupid friend sitting in the engine bay with a voltmeter hooked to the battery.

The best possible test that can be performed is with an SGII and that is what I did for you despite your antagonistic and manner-less attitude. I have gone out of my way for you and now I am done with you.

[1stToyota]

*sigh* You... just... don't... get it.

You cannot get 3 tanks of data without using the headlights or blinkers (I know some people never use their blinkers but I always do) so the usual testing method cannot apply. Nor can you ride down the road with the hood up and with a stupid friend sitting in the engine bay with a voltmeter hooked to the battery.

The best possible test that can be performed is with an SGII and that is what I did for you despite your antagonistic and manner-less attitude. I have gone out of my way for you and now I am done with you.

You've just got double standards and you haven't proven a thing. You're telling me that you can't do w/o ANY one single electrical load long enough to get the 6 tank average that you demand of others?

I don't know, since this is a thread about the heater...I think I could go long enough w/o using the heater if I was compulsive geek enough about it. BUT since your last posting was about the use of the radio I know that it's the ONE electrical load that certainly could be switched off long enough to run 6 tests. You say it causes extra fuel consumption, prove it expert. Is that too much to ask in a fuel economy forum that's based on so much testing and results? :iono:

And to get my quote right, I didn't mention a thing about testing headlights and blinkers...

"I need mileage logs for 3 tanks, using the radio, and 3 logs without the use of the radio, or your findings are meaningless"

Bye, BailOut :w00t:

[BailOut]

*sigh* I have to admit that you are wonderful at trolling. I only wish you would use that energy for something positive. I bet you could do some neat things if you put your mind to it.

There is no double standard here as a 6 tank test is simply not required to prove what we already know is true. 6 tank tests are only needed for for working with unknown factors. You asked for some numbers and so, even though I thought it was rather silly to do so, I went out of my way and got some for you. If you would like a more extensive test then feel free to do it yourself.

It doesn't matter what electrical device you wish me to go without for a 6 tank test because it is simply not my responsibility to satisfy your curiosity to that level regarding something that we already know. That responsibility is your own.

[1stToyota]

*sigh* I have to admit that you are wonderful at trolling. I only wish you would use that energy for something positive. I bet you could do some neat things if you put your mind to it.

There is no double standard here as a 6 tank test is simply not required to prove what we already know is true. 6 tank tests are only needed for for working with unknown factors. You asked for some numbers and so, even though I thought it was rather silly to do so, I went out of my way and got some for you. If you would like a more extensive test then feel free to do it yourself.

It doesn't matter what electrical device you wish me to go without for a 6 tank test because it is simply not my responsibility to satisfy your curiosity to that level regarding something that we already know. That responsibility is your own.

OP: Does it use more fuel?

You: Yes, using the heater and fan does use more fuel.

You just make statements then admit that you refuse to back them up with a 6 tank mileage log test?

"6 tank tests are only needed for for working with unknown factors."

Exactly. "unknown factors" equals statements about things like radios burning more fuel w/o even a single 6 tank test ever being done to back up one of those radio, turn signal, auto-dimming mirror, etc theories...??

Boy, I sure stepped in it when I asked you to provide actual proof that these things burn more fuel, didn't I? What you really provided was proof that your charging system was working properly, not how much of an actual hit you were taking at the gas pump. I don't want to be overly obsessive about everything from using backup lights to honking the horn and how many cents it will cost me, so I'll move on and leave you to yourself.

I'm done...and that means I won't come right back to this thread like you just did after claiming to be done. No proof was good enough for me.

[eTiMaGo]

I'm sorry guys but this thread has turned to plain old bickering on semantics... gonna close it before it gets any worse.