I Don't Think My Yaris Has DFCO

[Kaotic Lazagna]

okay, i tried a tank using DFCO...i just filled up and calculated my gas mileage. it says i got 36 mpg! my average without using DFCO and just pressing down on my clutch is 38 mpg...yeah, i don't think my Yaris has DFCO.

[BailOut]

That's odd. All NA Yarii have it, Kaotic, and yours is the first time I've ever heard of DFCO causing less MPG rather than a gain.

Are you sure you used DFCO properly (i.e. above 1,100 RPM and no clutch)? Were there other factors that changed your mileage this tank (i.e. colder temps,, different fuel station or type, more aggressive driving, inclement weather, low tire pressures, more weight in the car, shorter trips, more traffic, extended idling, etc.)?

[Ah Yum]

Don't sweat it. 38 is respectable to start with. :thumbsup:

[Kaotic Lazagna]

That's odd. All NA Yarii have it, Kaotic, and yours is the first time I've ever heard of DFCO causing less MPG rather than a gain.

Are you sure you used DFCO properly (i.e. above 1,100 RPM and no clutch)? Were there other factors that changed your mileage this tank (i.e. colder temps,, different fuel station or type, more aggressive driving, inclement weather, low tire pressures, more weight in the car, shorter trips, more traffic, extended idling, etc.)?

no, i'm not stepping on any pedals. the only things i did different were a couple more start up than usual, and using the A/C once on a very short trip (meaning no more than 15 miles, and the fan was set to 1 or 2 and wasn't on for the entire trip). i also drove 5 mph slower to compensate for the A/C. and i either switched to a lower gear or used the clutch once the RPM's hit 1500.

not sure if it makes a difference, but my Yaris was one of the first few batches in the Vallejo dealership...

[BailOut]

Ah Yum has a valid point but the oddity of this is bugging me. hehe

Please try the test I outlined in my original post in the DFCO thread to determine if you really do or do not have DFCO.

[El Jefe]

you guys get crazy mileage, i only get 32 at best (i've had 38 before but only on a freeway trip) but i pretty much only drive 'city' driving and im on it all the time, so 32 isnt bad, better than my cobra that got 19 on the freeway.

[BailOut]

Anyone can get good mileage in any car, and in the right car you can get outstanding mileage.

All it takes is changing a few things with the vehicle and changing a lot of things with your driving style and tactics. :biggrin:

[Kaotic Lazagna]

lol...i'm not comfortable running that test you outlined in your thread though. i might try another tank to see if i do/do not have DFCO

[Kaotic Lazagna]

you guys get crazy mileage, i only get 32 at best (i've had 38 before but only on a freeway trip) but i pretty much only drive 'city' driving and im on it all the time, so 32 isnt bad, better than my cobra that got 19 on the freeway.

i drive mostly freeway and average between 65-70 mph.

[Chris07LB]

Anyone can get good mileage in any car, and in the right car you can get outstanding mileage.

All it takes is changing a few things with the vehicle and changing a lot of things with your driving style and tactics. :biggrin:


Unless I am reading your site wrong, its shows your past few tanks with the MPG and the average speed driven..

I see 45mph speeds listed. If thats the case, its no wonder you get in the 40+ range per gallon.

Please correct me if Im wrong.

[sqcomp]

I'm seeing mid to upper 39's on average from mine. I don't use any "special" techniques (if DFCO is considered special). 99% of the time I never go past 3000 RPM, I'm trying to stay at 55 mph on the freeway at all times. I do occasionally hit 60 on those portions of the freeway that mandate that as the speed. Crusie control on as well and as little use of the fan as well.

[boris13]

Isn't it normal for automatics to get less MPG than the manual-trans models, overall?

[stuffy]

Isn't it normal for automatics to get less MPG than the manual-trans models, overall?

that is usually the case, but i think some cars with cvt trans get better mileage than manuals.

as far as the dfco method bailout has mentioned, i have been using it since the beginning of the current tank and so far it seems to be making a difference than just putting the car in neutral and coasting to a stop as i normally do.
i will know for sure once i refill.

[BailOut]

I see 45mph speeds listed. If thats the case, its no wonder you get in the 40+ range per gallon.
As you mentioned that is the average speed, taking into account city and highway driving (30-35 MPH in the city, 55-60 MPH highway). The reality of my daily commute is a twisting, winding, 2 lane, 30-50 MPH climb over a 4,500ft mountain (8,900ft summit), dropping 2,500ft on the back side, then the opposite on the way home. That is very far from optimal mileage conditions, especially in the colder months.

If you want to get better MPG on the highway the #1 thing you can do to help yourself is to slow down. Every MPH you drive over 55 takes away 1% of your fuel efficiency, and every MPH above 65 takes away as much as 5% due to the physics of aerodynamics. A common example used is that it takes an average of 20% more fuel to drive 70 than it does to drive 55. Get in the right-hand lane and stick to 55 MPH and watch your MPG shoot up.

Pumping up your tires to at least the max sidewall rating not only improves handling on wet and dry pavement but also increases MPG by decreasing rolling resistance, and increases the life of your tires by producing a much more even tread wear pattern. As an example I run my RE92's at 60 PSI for most of the year, dropping them to 44 PSI (which is the max sidewall) in snowy conditions.

Btw, the site linked in my sig, CleanMPG.com, isn't mine. I'm just a member and contributor. You can read much more about increasing your MPG there, and start logging your own fuel usage if you like.

[CASTREX]

every MPH above 65 takes away as much as 5% due to the physics of aerodynamics.

Pumping up your tires to at least the max sidewall rating not only improves handling on wet and dry pavement but also increases MPG by decreasing rolling resistance, and increases the life of your tires by producing a much more even tread wear pattern. As an example I run my RE92's at 60 PSI for most of the year, dropping them to 44 PSI (which is the max sidewall) in snowy conditions.




Last night I was doing 110 MPH, that means... 225% more fuel !!!! :eyebulge: well it was fun tough... :bellyroll:

60 PSI ???? :confused: that's like twice the recommended pressure for the car!!
So it's Toyota recommending low tire pressures for us to get bad MPG ??

[BailOut]

So it's Toyota recommending low tire pressures for us to get bad MPG ??
Toyota recommends a tire pressure based solely on ride comfort/smoothness rather than anything to do with mileage or handling.

The recommended 32 PSI is one half of the reason the Yaris feels like it's rolling laterally sometimes, especially in corners or high winds (the other half is the suspension). This is also one of the main things that leads to all the complaints of crappy and sluggish handling.

With the tires at 44-60 PSI there is a noticeably rougher ride as evidenced by slightly feeling a highway concrete joint in your seat when you used to just feel it on the control surfaces but that is a very small price to pay to get an MPG boost and much better handling.

For example, on the downhill side of my commute home there are 2 tighter-than-usual right-hand turns. They each have the warning signs for 30 MPH and back in my 32 PSI days I used to take them between 25 and 35 and could sometimes feel a little slippage. Now at 60 PSI I blow through there in a 5th gear DFCO at 45 MPH without so much as a tire squeal or wobble.

[Chris07LB]

Thanks for the info, Ill be sure to look into the site a little more.

Side not, you ever try doing 55mph even in the slow lane in NEW JERSEY??? Aint gonna happen!! :laugh:

As you mentioned that is the average speed, taking into account city and highway driving (30-35 MPH in the city, 55-60 MPH highway). The reality of my daily commute is a twisting, winding, 2 lane, 30-50 MPH climb over a 4,500ft mountain (8,900ft summit), dropping 2,500ft on the back side, then the opposite on the way home. That is very far from optimal mileage conditions, especially in the colder months.

If you want to get better MPG on the highway the #1 thing you can do to help yourself is to slow down. Every MPH you drive over 55 takes away 1% of your fuel efficiency, and every MPH above 65 takes away as much as 5% due to the physics of aerodynamics. A common example used is that it takes an average of 20% more fuel to drive 70 than it does to drive 55. Get in the right-hand lane and stick to 55 MPH and watch your MPG shoot up.

Pumping up your tires to at least the max sidewall rating not only improves handling on wet and dry pavement but also increases MPG by decreasing rolling resistance, and increases the life of your tires by producing a much more even tread wear pattern. As an example I run my RE92's at 60 PSI for most of the year, dropping them to 44 PSI (which is the max sidewall) in snowy conditions.

Btw, the site linked in my sig, CleanMPG.com, isn't mine. I'm just a member and contributor. You can read much more about increasing your MPG there, and start logging your own fuel usage if you like.

[CASTREX]

Toyota recommends a tire pressure based solely on ride comfort/smoothness rather than anything to do with mileage or handling.

The recommended 32 PSI is one half of the reason the Yaris feels like it's rolling laterally sometimes, especially in corners or high winds (the other half is the suspension). This is also one of the main things that leads to all the complaints of crappy and sluggish handling.

With the tires at 44-60 PSI there is a noticeably rougher ride as evidenced by slightly feeling a highway concrete joint in your seat when you used to just feel it on the control surfaces but that is a very small price to pay to get an MPG boost and much better handling.

For example, on the downhill side of my commute home there are 2 tighter-than-usual right-hand turns. They each have the warning signs for 30 MPH and back in my 32 PSI days I used to take them between 25 and 35 and could sometimes feel a little slippage. Now at 60 PSI I blow through there in a 5th gear DFCO at 45 MPH without so much as a tire squeal or wobble.

None of the following links agree with your statement.

I just think that running on 60psi tires is not very safe... even more if you are driving up and down a hill every day.

http://www.sportcompactcarweb.com/tech/0208scc_tire_pressure_guide/

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=72

http://www.nhtsa.dot.gov/cars/rules/TireSafety/ridesonit/brochure.html

[BailOut]

I hear you, CASTREX, and all I can say is this:

1) None of those articles ever took rolling resistance into account.

2) None of those articles looked at actual tire longevity.

3) These articles are usually written by the same folks that swear to this day that you absolutely must change your oil every 3,000 miles when Toyota says 5,000 - 7,500 (depending on the engine) and extended synthetics say 12,000 - 15,000.

4) Very few writers, or the organizations behind them, do their own science. They simply mimic what has been published elsewhere.

5) Don't forget that pumping the tires up higher greatly extends tire life so it goes directly against the interests of tire companies, tire sellers and tire installers to have you use a higher PSI.

6) Try it for yourself rather than letting others make the decision for you. However, if you don't want to pump up your tires you certainly don't have to. Like all other hypermiling facets it is left to personal taste.


Just know that Prius owners typically run around at 42/40 PSI on tires that are listed for 35 and several of us on CleanMPG.com are running around at 50+ not only without problems but with many tangible benefits.

[churp]

Pumping tires up higher than normal wears the center of the tread out faster, underinflated wears the outer edges of the tire out...at least with normal matched wheel and tread width. Granted the Yaris is light so wear will take a long time to show.

Sorry Bailout but I value my life more than a couple miles per gallon....in the midwest you won't catch me doing 55 in a 55 limit, I'd get run off the road...and in the 75 zones, 75 to 80 is a safe feeling.

[Kaotic Lazagna]

I'm seeing mid to upper 39's on average from mine. I don't use any "special" techniques (if DFCO is considered special). 99% of the time I never go past 3000 RPM, I'm trying to stay at 55 mph on the freeway at all times. I do occasionally hit 60 on those portions of the freeway that mandate that as the speed. Crusie control on as well and as little use of the fan as well.

really? when i used to drive 55 mph, i average no less than mid 40's mpg.

[El Jefe]

i guess thats my problem....i can't drive 55.....LoL

[d2dailly]

Thanks for the info, Ill be sure to look into the site a little more.

Side not, you ever try doing 55mph even in the slow lane in NEW JERSEY??? Aint gonna happen!! :laugh:

i feel ya. i am always doing about 80 in the fast lane but when i get people up my ass i hit 100 or 110 lol NJ has very aggressive drivers. guess thats why insurance is so high here

[Kaotic Lazagna]

i feel ya. i am always doing about 80 in the fast lane but when i get people up my ass i hit 100 or 110 lol NJ has very aggressive drivers. guess thats why insurance is so high here

wow, the fastest i've ever driven in my Yaris was 85 mph. LA also has some aggressive drivers.

[Astroman]

Ok, I'm a little fuzzy still on how to use DFCO. (I have an automatic.) So all I have to do is take it out of overdrive, put it into "3" and not press the gas pedal while say, going down a hill? Or do I have to put the key in the "acc" position and follow those steps? Forgive me for my ignorance.... I read through every single post on this and I'm just not 100% certain.... Thanks!

[BailOut]

Astroman:

There is no need to touch the ignition control. Just put the transmission in 3 or L and let your foot off the accelerator.

[Astroman]

Astroman:

There is no need to touch the ignition control. Just put the transmission in 3 or L and let your foot off the accelerator.

Thanks! That was very helpful and quite simple. :clap:

[Pavel Olavich]

Astroman:

There is no need to touch the ignition control. Just put the transmission in 3 or L and let your foot off the accelerator.

BailOut is correct! The A/T Yaris uses Grade-Logic (sorry to use a Honda term), and it works great, but I often manually shift to 3 and 2 to take advantage of (1) DFCO and (2) engine braking to save the old brakes.