From 650+ km/tank to 460km

[caper26]

This is killing me. I bought my 2010 new in April. Always got between 135-150km on the first bar, and about 650 or more on the tank. Now my last bar started flashing at about 460km today. Yes it is winter in NS, but this has been happening all fall, and we really had a warm season this fall. My driving habits are completely the same, Even if I go all highway or drive only 6 km to work, I get 95 on the first bar.... what gives??
Oh yeah, click the link (banner) below and look at the fill-up graph...

[caper26]

just filled up... 39.2 L of gas; 479 km = 8.2 L/100km. worst tank since I bought car. yuk. Only 11,500 km on vehicle. changed oil around 6,000 and upgraded to the 0W, or whatever it was (cant remember off hand). I thought the car was supposed to get BETTER with engine break in?? Doing a road trip today, all highway. Oil levels are perfect right now, and air filter looks brand new. Maybe I should try injector cleaner or something?? This is really pissing me off...

[Bluevitz-rs]

try pulling the EFI fuse in the engine bay and let the ECU reset. Maybe it's learned bad fuel trim values.?.?

Also, I've had a few REALLY bad tanks myself and I blame the gas, not the car.I've had bad millage from petro-can and husky gas. Ethanol is bad for millage, so try and avoid using it if you can.

[caper26]

I get all my gas from Irving. Not sure if they did something different after Sep. Is that fuse labeled?

[Bluevitz-rs]

Yeah, just pop the cover off and read the underside. It's all laid out. Just leave it out for min or so. But chances are it's just the gas. Try Shell gas for a full tank and see if it makes any difference.

[caper26]

No Shell around here unfortunately. I always used that in my Camaro when I lived out west. Irving or Ultramar or Esso here. Maybe I shoulda just filled up at one of the others just now...oh well, we'll see how this tank goes. Thanks for replying dude. Cheers.

[Bluevitz-rs]

I use ultramar myself with mixed results LOL.

[MUSKOKA800]

Winter Gas = Decreased mileage.
Cold intake air temps should also richen mixtures = more power but decreased mileage.

[caper26]

Winter Gas = Decreased mileage.
.
decreased, by over 50% ?? I was averaging about 5.5L/100km, and last tank was 8.2L. That's over 50% more gas; seems absurd.
I just drove all highway and got 104 km on first bar (used to get 145); speeds under 110 km/hr. I pumped tires up to 36 PSI before I left which is probably why I broke 100 km on the first bar...but otherwise, it's still doing the same thing as last few months. Pulling EFI fuse didn't do anything, but was worth trying.

[Bluevitz-rs]

It will take the ECU a while to relearn, but I didn't figure it was the culprit.

I was averaging around 600-650 on 41-43L. Then two tanks in a row I had 510 on 41L. The tank after that it was back up to around 590 on 41L, and the weather was colder than the bad tanks. So if you change gas stations and find your millage again, it's just bad gas. It happens.

[Yury]

Yeah, 8.2 with that much highway is kinda high. I seem to be getting 8.5 with virtually all city. That's auto too. On occasion, however I do get as low as 9.7. My driving patterns are a little unstable, but sometimes I do all super short trips...maybe that's when I get bad mileage..hard to be exact.
I am, like yourself, unsatisfied...I don't feel like a Yaris should be that low.

Your summer numbers though are great, I haven't seen anything like that when I was on the highway every day. 6.9 was my best. But than, I am not sure if we were on winter gas at that time yet, it was in Oct-November.

[caper26]

Update: Still getting crappy mileage. I talked to a service tech during an oil change (speaking of oil, I had changed over to the lighter weight oil on the first oil change for the car). He basically said the same thing as everyone eles... a combination of cold air and winter tires.
I did try warming the car up right before a gas up and highway trip to eliminate that aspect, but still got right around 100 km on first bar (vice 145 ish all highway). It is now march, and summer tires going back on and getting some new aluminum rims from crappy tire ($99 ea). The tech said they could do a detailed analysis by taking the car for a drive with a laptop connected to record data at predetermined speeds and averages. If, by June, I don't see an increase, I will be getting this analysis done.

[devinlamothe]

This is something you have to get used to. In the summer on my Hatch, I can get anywhere from 120-140km on my first bar. In the winter or when it's below zero, I can get anywhere from 60-80km on the first bar.

Now, I don't just go by the "first bar" as my MPG, I do calculate it. You can check my Fuelly and see just how bad the winter has been to my mileage lol

[caper26]

Thanks for that info devin. I wasn't expecting it to be THAT bad, so I thought something was actually wrong with my car! Time to put on new alloy rims and summer tires and see what happens on the next tank.!

[thebarber]

4 bangers love gas in the winter..

Granted I got 7L/100km supercharged doing 75mph in January...lol

[devinlamothe]

4 bangers love gas in the winter..

Granted I got 7L/100km supercharged doing 75mph in January...lol

lol wut.

Yeah doing highway speeds will actually get you decent mileage in the winter months, but city driving uggghhhhhh

[landrym28]

My last tank, last week, I managed to get about 550km on the tank. I'd say I do about 50/50 between city and highway driving.

As you mentioned, there's no Shell's in your area. I seem to get my best mileage when I buy at Shell, and I get the air miles too.

Usually in the winter, I get about 450km to a tank. Oh, and I'm lucky if I can get 110km on the first bar. Of course, it's tough to gauge your FE based on the first bar.

-Matt

[caper26]

temp this week supposed to be over 20C for next few days. Hope it is like that on Wed, because I just got my summer tires put on with new rims, and I have some highway driving to do on Wed (>300 km). Tires are at 36 psi.

[caper26]

Also, cleaned the MAF sensor and vacuumed out the intake box from debris, and also the air filter (dirty side). Will be putting in some lucas fuel treatment as well.

[caper26]

Update: It was normal to be getting 140 (+/- 5)km on first bar up until Oct. Then it was in the 90's all winter. Today, after 110 km, still no bars gone, I was like "yeah, let's keep it going" until at 113 km, bar went out. Ugh. I didn't expect much until I broke 200 and still only 1 bar gone. When fuel economy was good, 2nd bar was always around 90 km (144 on 1st bar, 230 when 2nd bar went out, ish). Kept a close eye on it, and it went out at 237 km!! So either the precision of the bars has changed, or the ECU wasted a bit on the first bar while it was re-learning fuel trims due to the seasonal changes I made (temp, tires, rims, MAF sensor clean, air filter & box clean, Lucas fuel treatment). the outside air temp was about 7C during the first half of the trip (1st bar) and rose to around 15-20 during the 2nd half (the return leg). I am hoping the ECU sorts itself out on this tank, and the next one is more stable. I also did about 45 mins to an hour of city driving with tonnes of lights, start-stops, etc...) during those 1st 2 bars, so I would have gotten quite a few more kms, had I been all highway. I hope this is a good sign of FE to come! I miss it! I will keep this thread updated.

[caper26]

5th bar out today @ 460 kms. (300 hwy, rest city/town)

[caper26]

also forgot to mention I filled up at Ultramar this tank too. Just stretched this tank to 677 km's ! and got 5.8L/100 km, and I am hoping that is with fuel trims a little out of whack during the first bit of the tank.

14 Jan/12 478.9 km 39.18 L 8.2 L/100km
01 May/12 677.5 km 39.55 L 5.8 L/100km

Check out the stats above, compared to january... about 200 km more on the same amount of gas... YUK! glad it is back, but I made so many changes, it is impossible to guess which one it was. temp is about the same for last couple tanks.

[thebarber]

i find temperature is 90% of the cause of mileage dip in the winter...

[devinlamothe]

also forgot to mention I filled up at Ultramar this tank too. Just stretched this tank to 677 km's ! and got 5.8L/100 km, and I am hoping that is with fuel trims a little out of whack during the first bit of the tank.

14 Jan/12 478.9 km 39.18 L 8.2 L/100km
01 May/12 677.5 km 39.55 L 5.8 L/100km

Check out the stats above, compared to january... about 200 km more on the same amount of gas... YUK! glad it is back, but I made so many changes, it is impossible to guess which one it was. temp is about the same for last couple tanks.

Most likely the temp and some of the cleaning you've done.

I just filled up today and got 6.7L/100km. Way better than the 7+ I've been getting when it's colder out.

Then again it has been pretty cold the last few weeks up here so I'm waiting until it's 20+ degrees to get my better mileage back.

[caper26]

well, that time of year again. I can anticipate watching my MPG slowly decline over the next few months again. I never did get back the same MPGs as the previous summer. The only thing I can think of is the ignition (plugs and/or wires).

[digitalrain]

46 MPG(according to your Fuelly) is pretty amazin if that's a mix of city and highway!

[caper26]

yes it is, and that is including really crappy mileage in winter. My average for the first 6 months was a LOT better than that, then winter hit, and then it never really went back 'the way it was'. And that is 46 mpg UK as well.

[digitalrain]

I get 37 MPG in the city and up to 57 MPG if only on the freeway. I'd sure love to be getting the same 46 MPG as yourself. Interestingly, for my car I didn't notice much difference between season as far as MPG goes.

[daf62757]

The longer I have my Yaris I am convinced that the reason some get some good mileage and some get bad mileage is good vs bad gas. It doesn't which brand you buy, where you buy it, or what time of the day you buy it. Bad gas will give you bad mileage and good gas will give you great mileage. Gas stations have no control over the quality of gas they get from the pipeline....they just sell it and you buy it....luck of the pump!

[thebarber]

his 46mpg is likely based on 4.5L/gallon, not the US 3.8L/gallon

all the same, the best usmpg i ever got was 42.6mpg (5.5L/100km) on the FIRST tank. drove fredericton to moncton, around the coast to the NS border, back to moncton then fredericton....

got ~7L/100km all city with intake/header/exhaust and ~7.5L/100km all city with i/h/e/supercharger

my vibe gt (2zz, 6speed) got 8L/100km this last fill...ftw

[digitalrain]

Yeah I think it is a IMP MPG figure. it's around 38-39 US MPG.

Very interesting that you got your best ever on the first tank of gas. Did you buy your car brand new or was there already miles on the odo?

I thought I'd get improved MPG after 10,000 kms when the engine was broken in , but there hasn't been any noticeable change either way.

I think I'd do better if I could find a source with no ethanol in it...:smile:

his 46mpg is likely based on 4.5L/gallon, not the US 3.8L/gallon

all the same, the best usmpg i ever got was 42.6mpg (5.5L/100km) on the FIRST tank. drove fredericton to moncton, around the coast to the NS border, back to moncton then fredericton....

got ~7L/100km all city with intake/header/exhaust and ~7.5L/100km all city with i/h/e/supercharger

my vibe gt (2zz, 6speed) got 8L/100km this last fill...ftw

[CB900F2]

Hi blue and all

Which is the ECU fuse to pull?

Thanks guys!


try pulling the EFI fuse in the engine bay and let the ECU reset. Maybe it's learned bad fuel trim values.?.?

Also, I've had a few REALLY bad tanks myself and I blame the gas, not the car.I've had bad millage from petro-can and husky gas. Ethanol is bad for millage, so try and avoid using it if you can.

[Bluevitz-rs]

Hi blue and all

Which is the ECU fuse to pull?

Thanks guys!

It should be labeled EFI

[Bluevitz-rs]

On another note, I've been driving really easy with some hypermiling involved by turning my engine off coasting down hills only and just in general driving really easy for the whole tank and I'm getting 5.3L/100km. My commute to work is all back roads 50km each way and lots of hills and stops. Driving the speed limit or a little over like normal and shifting between 1800-2000rpm with very light acceleration unless I need to go. Best tank so far was 780km with 41L to fill right to the top.

So that's 53mpg Imp or 44mpg US

[caper26]

amazing

[caineroad]

AT uses more more gas..

[caper26]

mileage already started to drop significantly. I never got back to the numbers I got last summer, so I am assuming new plugs make a difference. But I just got 80-something km's and first bar gone already. I don't even have winter tires on yet, nor snow on the ground, but the temps are dipping below 0 C now during the nights.

[caineroad]

does new plugs really help?

[WeeYari]

Changed my plugs at ~160K kms. Didn't change my mileage at all. Was a tad disappointed.

[caineroad]

Changed my plugs at ~160K kms. Didn't change my mileage at all. Was a tad disappointed.

how were the plugs looking at 160K? What plugs did u replace with?

If TB is clean, MAF is clean and plugs are good... what else could it be causing the poor mileage? I know temperature is a factor but when i bought the new car, it had very impressive mileage, now it's gone downhill.

[caper26]

how were the plugs looking at 160K? What plugs did u replace with?

If TB is clean, MAF is clean and plugs are good... what else could it be causing the poor mileage? I know temperature is a factor but when i bought the new car, it had very impressive mileage, now it's gone downhill.

Exactly. My mileage was WAY better 2 summers ago, and we had a crap summer (low temps, lots of rain). This summer past was constant sun and warm weather and my mileage was always worse than summer before.

[caineroad]

Exactly. My mileage was WAY better 2 summers ago, and we had a crap summer (low temps, lots of rain). This summer past was constant sun and warm weather and my mileage was always worse than summer before.

your average from fuelly is 38mpg... and mine is 32mpg.
(US mpg)


you are doing much better than me!

[caper26]

yes, but I am comparing myself to myself. I am only asking for consistency and wondering why it has gone downhill

[caineroad]

yes, but I am comparing myself to myself. I am only asking for consistency and wondering why it has gone downhill

can you please talk to toyota and their technicians to see whats going on, and let us know the result.

thanks

[caper26]

they want to take it for a ride with a laptop connected, for a hefty price of course.

[caineroad]

have u also tried sea foam ?

[caper26]

on a car with 20,000 K ? no I havent

[caineroad]

on a car with 20,000 K ? no I havent

Oh.. didnt know your car is so new... you barely drive this thing!!

I cleaned my MAF and TB yesterday, the car definitely feels smooth and pick up faster when i floor it. So I would assume the mpg to get better.

I also disconnected the battery for the ECU to reset for the whole night, not sure if that helps but it turned off the engine light(it was on after I cleaned the TB).

[caineroad]

But I just got 80-something km's and first bar gone already. I don't even have winter tires on yet, nor snow on the ground, but the temps are dipping below 0 C now during the nights.

i got 64km, first bar gone.... with esso gas

but yes normally it should be over 100, maybe bad gas, try using Shell. I get the best result from them.

But i suggest trying all gas stations including smaller ones around your place, so u know which one gives the best mpg

[jayeh]

i got 64km, first bar gone.... with esso gas

but yes normally it should be over 100, maybe bad gas, try using Shell. I get the best result from them.

But i suggest trying all gas stations including smaller ones around your place, so u know which one gives the best mpg

I have an '08. I usually get about 120-160km on the first bar. 350-450 at 1/2 a tank, then 50-100 km on the bottom half a tank. It's pretty strange. :iono:

I get around the same MPG on the tank no matter how fast/slow the gauge drops.

[caineroad]

I have an '08. I usually get about 120-160km on the first bar. 350-450 at 1/2 a tank, then 50-100 km on the bottom half a tank. It's pretty strange. :iono:

I get around the same MPG on the tank no matter how fast/slow the gauge drops.

dont lie to yourself

your average from fuelly is 423.6 km per tank.

[jayeh]

dont lie to yourself

your average from fuelly is 423.6 km per tank.

I don't see what that has to do with anything? :iono:

I've had 7 tanks where I've gone over 450km.

I'm referring to the strange way the gas gauge reads not implying some strange correlation between bars used and MPG.

[caineroad]

Just changed spark plugs, mpg still the same.

MAF and TB were cleaned, engine felt smoother and car runs faster but mpg still the same.

I think it has to do with the gas, i tend to get better mileage from Shell than Esso, and then the ethanol they put also contribute to lower mpg. A few years back there were no ethanol, and now it's 10% at most gas station. How much effect does 10% ethanol have on fuel economy, is it 10% worse? I don't think so, it could be more or less. That means the 10% ethanol (and other additives to keep them balance) can potentially affect mileage by 20%, which is just a guess. But without some scientific support, I am only guessing here.

Also gas station says up to 10%, the supplier of these fuel do they regulate the 10% enough? Do they do testing regularly to ensure the percentage?

I think it has to do with gas then. Nothing wrong with the car, everyone else is getting good mileage

[WeeYari]

^ there is a recent thread here discussing the age old question of any benefit to using premium. In that thread, another tangent developed which discussed effects of ethanol on mpg.

The forgone conclusion is that ethanol does not have a negative effect. I had the opportunity last summer to run ethanol free gas while on vacation. My own mpg calculations showed zero difference.

[caineroad]

^ there is a recent thread here discussing the age old question of any benefit to using premium. In that thread, another tangent developed which discussed effects of ethanol on mpg.

The forgone conclusion is that ethanol does not have a negative effect. I had the opportunity last summer to run ethanol free gas while on vacation. My own mpg calculations showed zero difference.

where is that thread and any scientific backup?

this is from a government website about reduced mpg with ethanol:
http://www.eia.gov/tools/faqs/faq.cfm?id=27&t=4

[jcboy]

+1 ^^^

Ethanol gives out less energy than gas equating to less power thus less mileage. I dont know why u didnt notice a difference other than the possibilty that u just stay idle on ur car so it only drives the aircon.

Seriously man, im not kidding.

[edmscan]

I have noted a 20% decrease in fuel economy for my Yaris since the start of "colder weather". I don't expect to see this decrease change until the end of the winter weather. Hopefully in spring I will get back to my normal mileage. Btw .. I was experiencing about 650 km per tank in the summer time and now it is about 520 km during the colder weather, so similar to the mileage decrease noted by the OP.

[WeeYari]

I dont know why u didnt notice a difference other than the possibilty that u just stay idle on ur car so it only drives the aircon.

Seriously man, im not kidding.

I was ecstatic with the thoughts of running ethanol free gas. Expected clearly visible, near earth shattering improvements. Not.

All I can say is, with my mpg logged with each and every one of 297 consecutive fill-ups since I took ownership of my car, the instances where ethanol free were used did not differ from fuel with ethanol added.

Power should only be 'necessary' during take-off and hill climbing. Once the vehicle is rolling, you essentially only need enough to maintain momentum. At this point, the lower power in ethanol gas would be negligable in its impact on f/e.

[caineroad]

I was ecstatic with the thoughts of running ethanol free gas. Expected clearly visible, near earth shattering improvements. Not.

All I can say is, with my mpg logged with each and every one of 297 consecutive fill-ups since I took ownership of my car, the instances where ethanol free were used did not differ from fuel with ethanol added.

This doesn't apply to everyone :clap:

[edmscan]

I was ecstatic with the thoughts of running ethanol free gas. Expected clearly visible, near earth shattering improvements. Not.

All I can say is, with my mpg logged with each and every one of 297 consecutive fill-ups since I took ownership of my car, the instances where ethanol free were used did not differ from fuel with ethanol added.


I also tried Ethanol free gas in my Yaris. The conclusion .. there was NO difference in fuel economy detected. The only place I noticed a difference was my wallet as it was more expensive.

[matti]

I have noted a 20% decrease in fuel economy for my Yaris since the start of "colder weather". I don't expect to see this decrease change until the end of the winter weather. Hopefully in spring I will get back to my normal mileage. Btw .. I was experiencing about 650 km per tank in the summer time and now it is about 520 km during the colder weather, so similar to the mileage decrease noted by the OP.

I've also seen an approximately 20% drop in fuel economy in the past month or so. My last car (Corolla) had a similar reduction in cold weather.

[allyart]

in my place (jakarta,indonesia) getting a 12km for 1litre is very good, considering the traffic jam around here

[Viperoni]

Power should only be 'necessary' during take-off and hill climbing. Once the vehicle is rolling, you essentially only need enough to maintain momentum. At this point, the lower power in ethanol gas would be negligable in its impact on f/e.

That's not the way it works.

When ethanol is substituted into the fuel, it reduces the amount of energy in the fuel - so there's less energy in the fuel.
That translates into less energy per unit volume in the fuel and less overall energy in the entire tank of gas.
You *should* see a difference in gas consumption.

I know I drop down from ~500km per tank (40L fillup) to ~450km per tank once winter fuel starts getting supplied at the pumps.

[Bluevitz-rs]

^x2

Though my millage is higher per tank, the drop is about the same. 650-700 in the summer and 550-650 in the winter. It really depends on how many short trips I make and the temp.

[edmscan]

My last 2 fill ups (partial fill ups) have been about 7.3 L/100 KM or 32 US MPG as compared to 40 US MPG during the summer time. So .. there seems to be some consistency here. It is 100% city driving with no highway driving.

Looks like my fuelly is sure taking a hit during the winter time.

[jayeh]

My last 2 fill ups (partial fill ups) have been about 7.3 L/100 KM or 32 US MPG as compared to 40 US MPG during the summer time. So .. there seems to be some consistency here. It is 100% city driving with no highway driving.

Looks like my fuelly is sure taking a hit during the winter time.

I'm glad I'm not the only one. My MPG dropped quite a bit and when I switched my snow tires from the very very heavy generic steelies to a set of toyota steelies that were about half the weight. My last tank was only 30 mpg! :mad:

Now it's sitting at about 33.5mpg on this tank according to the scan gauge.