Fuel Efficiency and the Yaris

[marcus]

Originally Posted by voodoo22

A lot of whacky factors contributed to me getting my best tank of gas yet

Against:

cold morning weather
winter tires on

For:

only 2 short trips, the rest of the tank was all commute or highway driving on a shortish weekend trip which spanned just over 300 kms.
unusual blast of warm afternoon weather
no traffic jams
Oil change halfway through the tank where I got a new air filter

Somehow this combination equals

882.8 kms using 37.916 litres
4.29 l/100km
54.75mpg

I don't think I will be easily beat this mark. That shows how much of a difference those little trips make as in much better weather with all season tires, my previous best was 53.7mpg.

the most i do on 37liters is 600km if im lucky...

[metalshark]

Hate to ask again but don't they sell imperial gallons in Canada?

[Jister]

Very nice thread,
Yesterday was my first driving the yaris for longer distance - about 500km (~300 miles)
fuel consumption for the first 250km (150 miles) was - 9.5 l/100km (24.7 mpg)
for speeds between 120 - 140 kmph (75-87 mph) plus one time testing top speed - to 200 kmph (125 mph)

for the other 250 km (150 miles) my foot was very light :) just trying to keep constant speed - FC was 7.6 L/100km (31mpg) for speed between 100 -120 kmph (62 -75 mph)

the test was made on the highway with 2-3 stops for a rest
there was 3 people in the car all the time
the Car is yaris TS 2008 - 1.8L dual VVT-i

my next target is to try some road with maximum speed of 90 kmph (~56mph) and using DFCO - If I manage to make 5.9L/100 km (40mpg) with this engine - WOW! :)
Of course it cannot be compared to my motorcycle FC :) with full throtle open every time that is possible and speeds around 150 - 180+ kmph (93 - 112+ mph) FC is no more than 6.5 - 7 L/100km (36 - 33 mpg) it's the ultimate green peace machine :)

[voodoo22]

Originally Posted by metalshark

Hate to ask again but don't they sell imperial gallons in Canada?

The gas stations sell in litres, the car companies advertise in IMP MPG, because they can create the illusion of better numbers, just like how they sell meat here per kg, but advertise prices based on lbs.

My last tank would be 65.79 IMP MPG.

[voodoo22]

We managed to avoid almost any short trips again this tank and even though I got stuck in a hideous accident traffic jam one day which added 1 hour to my commute, had freezing rain, snow, strong winds and most mornings/many afternoons below 0 celsius, I still managed to eek out over 51 US MPG on these Nokians. Could have done better, but with gas prices getting cheaper people are driving exceedingly fast again and I was a lot closer to or on the 90 km/h mark than when gas was 1.40 a litre.

I am very surprised I can get over 50 under these conditions, but I wonder what I could do in the summer if I cut out the shorter trips then? Seems for me it's worth about 2-4 mpg more on a tank.

[mchllp925]

I now have 7,000 kms on my 08 Yaris and I am still only getting 10 km per litre or about 22 mpg. This is half of what Toyota has rated for this car.
My dealership says I should get better mileage when I have 15, 000kms.
Does this sound right?
Love the car but I expected better then this for mileage.
P.S. this is city driving

[BailOut]

Hello Darrin,

It is likely your driving style that is hurting your mileage. Please read through the first few posts in this thread and then try adjusting some of your habits accordingly. Let us know if no MPG improvement occurs.

[mchllp925]

Thanks! I read your earlier posts and will definitely impliment many of those points. Up here in Winnipeg our winters are harsh ( 2-3 months of -20 to -40 celsuis temps) so I will need to idle for at least 30 secs to ensure oil movement to the heads before moving.
Taking out the spare will help save gas? I will try that ( only thing in there)I was not aware of the DFCO so I will be looking for that.

So I will respond later with hopefully a better mpg.
Thank you again for the tips!
Darrin

[mchllp925]

Hi, me again, Just went to get the morning paper and I tried to keep the acceleration 2,000 rpm or lower. WOW I really am a lead foot. It took a little concentration to do that, usually got to the speed limit as quick as I could.
Ho boy can I see the fuel savings.
Darrin

[voodoo22]

Originally Posted by mchllp925

Hi, me again, Just went to get the morning paper and I tried to keep the acceleration 2,000 rpm or lower. WOW I really am a lead foot. It took a little concentration to do that, usually got to the speed limit as quick as I could.
Ho boy can I see the fuel savings.
Darrin

Hi Darrin,

I was born and lived in Winnipeg for quite a few years. I would think your biggest issues for getting great FE there (after you become more disciplined in your driving style) will be:

1) short trips - I've read in colder weather it can take 20kms for the car to reach optimal operating temperature and I would guess there's a good chance most of your trips will be less that. Combat this by walking or taking transit whenever possible, combining your short trips together so the engine doesn't completely cool down between trips, using your heater block and a grill block*.

2) stop & go - I always find Winnipeg to have far too may stop signs & lights. Portage near main? There's a red light every intersection! Accelerate as slowly as possible from a dead stop and get off the gas and coast asap when approaching a red light. Also, plan your routes to avoid lights. I used to drive through the zoo and on Wellington (even though it was out of my way a little), because of the lack of lights or stop signs and the nice curves in the road.

3) weather - the winter months are going to shave a lot off your mpg. Maybe 10% or more when it gets to -30 celsius every day in February! Use your block heater and combine short trips.

4) road conditions - roads that aren't plowed in the winter and poorly drained roads which easily flood in the summer are going to be your own worst enemy. Ride it other peoples tracks and try to stay on the dry parts of the road.

Of course, these are just some tips (I don't feel like typing more). When the speed limit is 60 or less, there's no reason why you can't keep your rpms under 2200 100% of the time. Inflate your tires to max sidewall, and I can't stress enough to go as lightly on the gas pedal as possible.

Unless all your driving is over very short distances (under 10km) and you have no choice but to drive in horrible stop and go traffic, there is no reason why you should be able to attain over 35 US MPG 100% of the time. Once you become experienced and more disciplined you should be able to consistently break 40 US MPG in the summer.

Check out cleanmpg for a more thorough guide on how to consistently achieve great FE in your conditions. There's no trick to it, just hard work and discipline.

*I wouldn't recommend a grill block unless you have something for measuring the engine temperature to be safe.

[mchllp925]

All I drive is less then 10 kms. I live out in Transcona and drive to Palliser on Kernaghan. I have definitely found my driving habits are bad. So far in 1 day I have mastered taking off slowly from a stop and not going over 2,000 rpm.
I am still concentrating on coasting to stops. 26 years of bad driving habits wont change overnight, but I'm giving my best. LOL
At least I can't fault my Yaris.

[voodoo22]

Originally Posted by mchllp925

All I drive is less then 10 kms. I live out in Transcona and drive to Palliser on Kernaghan. I have definitely found my driving habits are bad. So far in 1 day I have mastered taking off slowly from a stop and not going over 2,000 rpm.
I am still concentrating on coasting to stops. 26 years of bad driving habits wont change overnight, but I'm giving my best. LOL
At least I can't fault my Yaris.

It took me 3 years to get to where I am now and that was after about 16 years of driving much less disciplined.

I'm interested to see what sort of MPG you're going to be able to get in those conditions as they are definitely close to the worst you can have for FE, but at least you don't have to drive through the Mountains like Bailout. At least Manitoba is flat, flat, flat

Keep in mind, no matter what you get now, you will see much higher numbers in the summer, so if you can stick with it and hone your skills (like it sounds you are), you're really going to reap the benefits during that one warm week in July

[orheen]

For the fuel consumtion of yaris 1.0 your speed must be at 65 km/h when only driver in the car. When you 5 people your speed must be 100 km/h

yaris 1.3 best fuel comsumption speed 78 km/h

yaris 1.4 d-4d manuel 78 km/h

yaris 1.4 d-4d multimode 68 km/h

I will put the diagrams here that show speed - strenght. And fuel consumptions.

[TT75]

Hi all,

I regularly collect the fuel consumption of my Yaris. In the picture you can see the collected data. I hope it will give you an idea about Yaris's fuel consumption.
Note:
At each filling of fuel tank, it is completely filled with fuel until the tank is almost overflow.

[marcus]

wow......great lookin graph.. good job..atleast ur stats are more realistic..very close to mine...i just dont get how people getting 800km on a 37 liters...i think ill get bored hypermilling the whole time..

your dec 11th 2008 was a little weird seems not possible unless you kept ur engine running in neutral for a very long time.. plus it shows hwy.. you going 180km/hr the whole time??

[TT75]

Originally Posted by marcus

wow......great lookin graph.. good job..atleast ur stats are more realistic..very close to mine...i just dont get how people getting 800km on a 37 liters...i think ill get bored hypermilling the whole time..

your dec 11th 2008 was a little weird seems not possible unless you kept ur engine running in neutral for a very long time.. plus it shows hwy.. you going 180km/hr the whole time??

Thanks for your comments. I think it may be possible to run 800 km with 37 liters (37/8=4.6 lt/100km) if the car is Yaris D-4D (Diesel engine) and if it is going on highway. Beacuse, D-4D has a theoretical value of 4.5 lt/100km on highway. However, it is nearly impossible to get 4.6 lt/100km with 1.3 VVTi engine (gasoline).

The record on Dec 11th 2008 is for a long trip on highway. You are right that my speed was around 150-180 km/h for whole the trip. Actually, board computer says it is 7.9, but the calculation says it is 8.1 which is even higher :).

[knowmercy]

You know, this article is an absolutely great resource! I'd like to offer some, hopefully insightful information to it. Some of these suggestions do make your car use less gasoline, however they can substantially wear on other parts of the vehicle. For instance, shifting at 2k rpms will almost certainly lug the motor and the risk of detonation is considerably higher at rpms that low. The second thing about that is you actually burn less fuel depending on the engine load at the time. So shifting at 2500 or 3k under light load burns about the same amount of fuel as shifting at 2k under moderate load or heavy load. You press on the gas harder, more air comes in and the engine puts more fuel in there. Also, turning off the engine at lights is horrible for it. Every time you restart the engine it takes a short period of time to rebuild a "safe" amount of oil pressure in the engine. This is not achieved if you start the engine and drive off. Not to mention the wear on the starter, relays, and fuel pump. Not trying to be a downer on any of the resources that have been made available. Making a car use less fuel doesn't equate into the best health for the car. Also, always running your car at low rpms actually creates a TON more carbon build up inside the engine. I hope this is helpful to folks who are trying to not only save fuel, but keep their car running for a long time. :)

[BailOut]

Welcome to the forum, knowmercy. I know you meant well with your post and I appreciate that, but I disagree with most of what you presented.

Originally Posted by knowmercy

For instance, shifting at 2k rpms will almost certainly lug the motor and the risk of detonation is considerably higher at rpms that low.

The ECU adjusts for this by retarding the ignition timing by quite a bit. I have never heard any audible indicators of pre-detonation.

Originally Posted by knowmercy

The second thing about that is you actually burn less fuel depending on the engine load at the time. So shifting at 2500 or 3k under light load burns about the same amount of fuel as shifting at 2k under moderate load or heavy load. You press on the gas harder, more air comes in and the engine puts more fuel in there.

The fuel/air map in modern engines is anything but linear, and using a simple tool like a ScanGauge shows that what you say here is just not the case. The loads do not always occur where you think they do.

Originally Posted by knowmercy

Also, turning off the engine at lights is horrible for it. Every time you restart the engine it takes a short period of time to rebuild a "safe" amount of oil pressure in the engine. This is not achieved if you start the engine and drive off.

While it is easy to believe statements like this they simply are not true. Oil pressure has nothing at all to do with the current coverage of oil on any part of the engine. Pressure only lifts oil from the pan to the top of the block where it begins a gravity-fed trip back to the pan. Oil does not magically disappear from all internals the second you turn off the ignition.

Originally Posted by knowmercy

Not to mention the wear on the starter, relays, and fuel pump.

As is mentioned in the first posts in this thread, the break even time for idling versus all wear and tear on a modern vehicle is just 7 seconds. If you can't wrap your head around that number then allow me to show you a real world example:

Even with the carpoolers, equipment, snow, elevation and climbs I deal with I still average about 46 MPG. I think we can all agree that the median MPG for all Yaris owners is 32 MPG. I drive roughly 17,000 miles per year. At 46 MPG I use 370 gallons of fuel. Someone at 32 MPG uses 531 gallons to go the same distance. With fuel at $2.50/gallon I will spend $925 on fuel for the year while the 32 MPG-er will spend $1,328. This means I save $403 per year in fuel costs.

To put that into perspective a starter replacement costs about $180 and comes with a lifetime warranty (I am at 37k miles and still on the OEM starter despite using it more than a dozen times per day). A replacement fuel pump costs about the same (I am still on the OEM). Relays are all less than $20 (I am still on the OEM).

In other words, even if I had to replace one of those items every year I would still come out way ahead.

Originally Posted by knowmercy

Also, always running your car at low rpms actually creates a TON more carbon build up inside the engine.

This is inaccurate. Carbon buildup occurs due to incomplete combustion and exhaust processes. This condition is rare in the Yaris due to the tight control the ECU exerts, and from posts in the tuner forums I would say that it is far more likely to occur at high RPM than low. It's not like I have torn down my engine but I see no signs of carbon or sludge anywhere that is easily accessible (none under the oil cap area, nothing in the throttle body, no fouled O2 sensors, etc.).


Again, I know you meant well, but spreading disinformation helps no one. In the future please be sure to research any information you have before sharing it, and never, ever be afraid to perform your own research.