Tire Pressure & Fuel Economy - Toyota Yaris Forums

enkid · 12-04-2006, 10:34 PM

I got my 5-speed Yaris sedan in August. My second through 5'th or 6'th tank of gas gave me from 48 to 53 MPG US 5% city /95% hwy. I think 52-53MPG was with 100% gasoline, and 48-50MPG was with 10% ethanol. Then I pumped up my tires to 42PSI, and at the same time the weather started getting colder. My mileage dropped to 42 - 44MPG. I did another 6 or 7 tanks full, averaging about 43MPG. Then 2 tanks ago, I checked my tires pressure - was 40PSI. I reduced it back to 32PSI. Immediately my gas mileage went back up to about 48MPG! This is backwards from what I'd expect. They're stock tires Goodyear Eagle GT's.

Has anyone had a similar experience?

BMGYaris · 12-05-2006, 12:53 AM

you sure you are in america?

vodkalush · 12-05-2006, 09:40 AM

what is stock tire pressure suppose to be at 32 or 42 (15inch steelies)?

Andrew Chalmers · 12-05-2006, 09:45 AM

Quote:

Originally Posted by enkid

I got my 5-speed Yaris sedan in August. My second through 5'th or 6'th tank of gas gave me from 48 to 53 MPG US 5% city /95% hwy. I think 52-53MPG was with 100% gasoline, and 48-50MPG was with 10% ethanol. Then I pumped up my tires to 42PSI, and at the same time the weather started getting colder. My mileage dropped to 42 - 44MPG. I did another 6 or 7 tanks full, averaging about 43MPG. Then 2 tanks ago, I checked my tires pressure - was 40PSI. I reduced it back to 32PSI. Immediately my gas mileage went back up to about 48MPG! This is backwards from what I'd expect. They're stock tires Goodyear Eagle GT's.

Has anyone had a similar experience?

Higher psi isn't always more efficient if the rubber is losing traction because the tire is too hard.

BMGYaris · 12-05-2006, 10:24 AM

The manual recommends 32 psi all around, or the front two tires something like 5 psi higher if you regularly exceed 100 mph. i just dont understand 50+ mpg using american gallons...

eco · 12-05-2006, 11:56 AM

I only got over 42mpg once(42.3),and that was in the summer,no a\c on,windows up,going 60mph,and had 39 psi in my 17" tires that take upto 50psi.

60 Somethings · 12-05-2006, 01:44 PM

Have to wonder about the calculation abilities of those getting in the 40MPG+ range on a more than a very occassional basis.

My calculations, and that of my ScanGaugeII, show about 34.5 MPG in city driving right now, on "winter" gas. We keep up with traffic (not very hard to do) and hit 4,000 RPM occassionally. The tires are kept at 34lbs.

It's nice to know we could squeeze out more mileage if gas was in short supply, but wouldn't expect much more than 36-37 based upon our experience. Very happy with mileage/performance trade-off.

keesue · 12-05-2006, 02:48 PM

I have mine set at 32 psi and I am getting 36 mpg (US Gallons) consistently with mostly freeway driving 75/25 split.

12-04-2006, 10:34 PM	#1
enkid Drives: 07 Yaris Sedan Join Date: Nov 2006 Location: RI, USA Posts: 25	Tire Pressure & Fuel Economy I got my 5-speed Yaris sedan in August. My second through 5'th or 6'th tank of gas gave me from 48 to 53 MPG US 5% city /95% hwy. I think 52-53MPG was with 100% gasoline, and 48-50MPG was with 10% ethanol. Then I pumped up my tires to 42PSI, and at the same time the weather started getting colder. My mileage dropped to 42 - 44MPG. I did another 6 or 7 tanks full, averaging about 43MPG. Then 2 tanks ago, I checked my tires pressure - was 40PSI. I reduced it back to 32PSI. Immediately my gas mileage went back up to about 48MPG! This is backwards from what I'd expect. They're stock tires Goodyear Eagle GT's. Has anyone had a similar experience?

12-05-2006, 09:40 AM	#3
vodkalush I drive a yarrrris View User's Garage Drives: 07 Sedan Polar White Join Date: Sep 2006 Location: Rochester, NY Posts: 1,009	what is stock tire pressure suppose to be at 32 or 42 (15inch steelies)? __________________ Docotrs say all the drikning has mesesd up my seplilng and radieng Get your YarisWorld.com stickers here!!! The Official Toyota Thailand Accessories Order Thread will work for parts

12-05-2006, 01:44 PM	#7
60 Somethings Old Folks View User's Garage Drives: 2007 Yaris LB, 2006 4Runner V8 Join Date: May 2006 Location: Vancouver, USA Posts: 222	Have to wonder about the calculation abilities of those getting in the 40MPG+ range on a more than a very occassional basis. My calculations, and that of my ScanGaugeII, show about 34.5 MPG in city driving right now, on "winter" gas. We keep up with traffic (not very hard to do) and hit 4,000 RPM occassionally. The tires are kept at 34lbs. It's nice to know we could squeeze out more mileage if gas was in short supply, but wouldn't expect much more than 36-37 based upon our experience. Very happy with mileage/performance trade-off. __________________ We are the proud owners YARI - He's a loaded Silver LB with ATTITUDE!

12-05-2006, 02:48 PM	#8
keesue Chillin' out by the Bay Drives: 2007 Yaris Liftback Join Date: Nov 2006 Location: The back streets of San Fran Posts: 151	I have mine set at 32 psi and I am getting 36 mpg (US Gallons) consistently with mostly freeway driving 75/25 split. __________________ Gettin' all the way down. Meteorite '07 HB STILL completely stock; but.... checkin' out da other ones to see what's what.

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12-05-2006, 12:53 AM	#2
BMGYaris Drives: Yaris 3dr Hatchback Join Date: Oct 2006 Location: South Carolina, USA Posts: 255	you sure you are in america?

12-05-2006, 10:24 AM	#5
BMGYaris Drives: Yaris 3dr Hatchback Join Date: Oct 2006 Location: South Carolina, USA Posts: 255	The manual recommends 32 psi all around, or the front two tires something like 5 psi higher if you regularly exceed 100 mph. i just dont understand 50+ mpg using american gallons...

12-05-2006, 11:56 AM	#6
eco Drives: 2007 Black Yaris sedan Join Date: Sep 2006 Location: Atlanta Posts: 884	I only got over 42mpg once(42.3),and that was in the summer,no a\c on,windows up,going 60mph,and had 39 psi in my 17" tires that take upto 50psi.