Fuel Efficiency and the Yaris

[Yaris Hilton]

Just a passing troll. Don't feed him.

[jjonrofl]

To the people who get 40+mpg- do you do only highway driving? I do about 70% city / 30% highway and have only managed 33mpg... :(

[Rikster]

Currently doing 47mpg, in my 1.0 3cylinder

[KrazyDawg]

What's the optimum speed for driving on say a flat road? Would it be 55 MPH? Less? If anyone has a scangauge, I would be interested in the numbers. I have a 6-7 mile section in my commute where the speed limit is 50 MPH but there are stop lights.

[BailOut]

Originally Posted by Rikster

Currently doing 47mpg, in my 1.0 3cylinder

You're off to a great start, Rikster! You should be able to stomp on us folks in the U.S. that can only get the 1.5L.

Originally Posted by KrazyDawg

What's the optimum speed for driving on say a flat road? Would it be 55 MPH? Less? If anyone has a scangauge, I would be interested in the numbers. I have a 6-7 mile section in my commute where the speed limit is 50 MPH but there are stop lights.

Hi, KrazyDawg. Using the SGII many of us have verified that 35-45 MPH is the sweet spot for efficiency on relatively flat roads. The 10 MPH difference is a broad range that depends on many factors such as tire pressure, road quality, wind resistance, ambient temperature, etc., but the common sweet spot within that range seems to be between 37-39 MPH.

[KrazyDawg]

Originally Posted by BailOut

You're off to a great start, Rikster! You should be able to stomp on us folks in the U.S. that can only get the 1.5L.



Hi, KrazyDawg. Using the SGII many of us have verified that 35-45 MPH is the sweet spot for efficiency on relatively flat roads. The 10 MPH difference is a broad range that depends on many factors such as tire pressure, road quality, wind resistance, ambient temperature, etc., but the common sweet spot within that range seems to be between 37-39 MPH.

Thanks Bailout. There's been a few occasions where someone drives at 40 MPH on the 50 MPH strech and I usually go around because I thought the sweet spot was around 50-55.

[Rikster]

Originally Posted by BailOut

You're off to a great start, Rikster! You should be able to stomp on us folks in the U.S. that can only get the 1.5L.



Hi, KrazyDawg. Using the SGII many of us have verified that 35-45 MPH is the sweet spot for efficiency on relatively flat roads. The 10 MPH difference is a broad range that depends on many factors such as tire pressure, road quality, wind resistance, ambient temperature, etc., but the common sweet spot within that range seems to be between 37-39 MPH.

Well it's not really fair, holland's landscape is all flat :D which come's in handy when it come's to fuel efficiency!

[Yaris Hilton]

Originally Posted by KrazyDawg

What's the optimum speed for driving on say a flat road? Would it be 55 MPH? Less? If anyone has a scangauge, I would be interested in the numbers. I have a 6-7 mile section in my commute where the speed limit is 50 MPH but there are stop lights.

For most cars under steady state, level ground conditions, maximum mileage is found in the vicinity of 35 MPH.

[Kal-El]

Originally Posted by KrazyDawg

What's the optimum speed for driving on say a flat road? Would it be 55 MPH? Less? If anyone has a scangauge, I would be interested in the numbers. I have a 6-7 mile section in my commute where the speed limit is 50 MPH but there are stop lights.

And that's unfortunately where we waste most of our gas - every time we have to stop. Getting back up to speed is the killer.

I'd estimate that the Yaris achieves between 45-55 mpg if it is kept very steadily at 40 mph on a level road with no head wind.

[sickpuppy1]

Well I cant gripe! Just got my 2010 Yaris sedan last Saturday, filled up by the dealer, so not sure how well it was done. Anyways, I have a tendancy to "top it off" , but I filled it slowly and checked at the 1st click. 10.2 gallons,lol pretty low. 40.9 mpg for 418 miles .When topped off at 10.8 gallons its 38.7 mpg. Not bad for the first tank. That 418 miles is total on the car, so were a couple of thousand away from broke in. And to be honest, not being used to the car and not using the cruise much, I've found myself between 75 and 80mph at times. Anyways, lovin it so far!! I'm gonna bump the tire pressure a bit and see how I like it. I'm not gonna go the hyper miler route, but will adjust driving to a certain extent to help. I owned a 2001 Civic before this and routinely got 36-38 with it.

[Ranger SVO]

So far I'm very happy with my Yaris. Last week I drove 218 miles and put in 5.52 gallons of gas. Thats about 39.5 miles per gallon. In my opinion, thats really good.

About 80% of my driving is highway, the rest city. Awesome little car

[Falconia]

Originally Posted by BailOut

You're off to a great start, Rikster! You should be able to stomp on us folks in the U.S. that can only get the 1.5L.



Hi, KrazyDawg. Using the SGII many of us have verified that 35-45 MPH is the sweet spot for efficiency on relatively flat roads. The 10 MPH difference is a broad range that depends on many factors such as tire pressure, road quality, wind resistance, ambient temperature, etc., but the common sweet spot within that range seems to be between 37-39 MPH.

You mean the real speed or the speed that speedometer shows. I just checked with navigation system that speedometer shows 4,4mph above real speed

[Hypermiler]

I am using a ScanGauge II to help me get the most out of a gallon of gas. Since I got it, I have been monitoring the ScanGauge II and have been able to manage a new best of 47.5mpg. That was the fuel economy average for a ride home from work, a 34 mile drive. It is flat, speed limit if 50mph, and only a few stops... Ideal for generating great mileage numbers.

But 47.5mpg is in Prius and the econobox diesel range - AWESOME for a $15k car!!!

[BailOut]

^^ Well done!

[pawsplus]

Got 40 mpg on my second tank!! I drive mostly on state roads/back roads. Not too many stop signs but lots of hills and turns and slowing down and speeding up. Some in the city. Wasn't on the interstate at ALL during this tank!

[talnlnky]

Originally Posted by sickpuppy1

I'm not gonna go the hyper miler route, but will adjust driving to a certain extent to help. I owned a 2001 Civic before this and routinely got 36-38 with it.

hahaha hahahaha.... yes you will, just wait 3-6 months, after what... 2 weeks you are already tracking fuel efficiency and posting about it... HYPERMILER HERE YOU COME!

[Boost Addicted]

''2) Accelerate and brake slowly and steadily, avoiding jackrabbit starts and stops. No one ever got a trophy for getting to the next red light first or getting up to highway speed in the first 200m of an on-ramp, and you can't beat the timing of a stop sign. In the Yaris I try to never let my RPM get above 2,000 unless I need to merge quickly, in which case I allow for 2,200. The only time I get higher than that is on the climbing side of my mountain commute, as once you get into 6% and 7% grades it simply requires more fuel to keep moving.''

Shifting and accelerating at such low RPM's is actually very hard on the transmission and engine.... We've had multiple cars in the shop with tranny problems because people are afraid of RPM's.

It is fact that MPG, at a X miles per hour, is un-affected by RPM's. You could be at 2K or 5K, at X speed, you're getting the same fuel mileage. The difference is engine and transmission load.

And trying to accelerate from lower RPM's puts a huge load on the engine, and actually uses much more fuel than if you accelerate from 3000 RPM's. Think of it like riding a mountain bike. Does it take more energy to get to 10mph in the highest gear, peddling slowly (due to the force it takes), or in the lowest gear at a faster rate, with great ease?

Trust me on this one lol, do NOT be afraid of RPM's, it doesn't affect fuel mileage in the terms stated above. Do your engine and tranny a favor by shifting at 3K or even a bit higher. I'm rarely cruising below 2 grand... And I get great fuel mileage.

Not tryin' to stir up arguments here, just letting you guys know what I've learned throughout the years of going to school for this as well as field work.

=)

[Boost Addicted]

'10) and never idle it to warm it up. The Yaris offers a low coolant indicator light in the dash panel that let's you know when it is running in its least fuel efficient state. As for idling to warm it up, remember that you're getting exactly ZERO MPG while idling.''


I also have to disagree with this lol. As you DO get zero mpg while warming up, you're getting worse fuel mileage driving it cold, especially in the winter... In the summer, not so much.

But in the winter, metal shrinks even more with the colder weather, and your tolerances are loose (eg. piston rings, oil pump gears, valvetrain) making operation sloppy, inefficient, and less resistance to wear. In addition, the coolant temp sensor will dump a bunch of extra fuel until the engine is at its operating temperature... So even though you're running rich at idle to warm it up, you're still using more fuel when driving it cold...

Ofcourse, when you measure lost MPG's when letting it warm up at idle, vs driving it right off the bat, numbers will be lower... But if you calculate volume of fuel used to warm the vehicle at idle vs. volume of fuel used to warm it driving when its cold, idle will get better mileage every time.

In summer weather its really not necessary.. But regardless of ambient temperature, you shouldn't put the car in gear untill 10 seconds after ignition to allow for oil to properly lubricate all parts of your engine

Just my .02 :)