Bigger Rims Better MPG?
 

Is it true that if you get larger and lighter wheels on your car you will get better MPG. Or are the stock wheels ideal?

Re: Bigger Rims Better MPG?
 

Lighter, yes.

Bigger wheels, assuming shorter tire sidewalls, would simply mean more shock travel/heating that would otherwise go into tire sidewall flex.

Otherwise simply a question of comfort.

Better to have the tire and suspension absorb the road "undulations", not the entire vehicle weight.

Re: Bigger Rims Better MPG?
 

Not necessarily so in the 2008, NHW20 models. Toyota came out with a "Touring" car and though the wheels are a little larger, they used a smaller sidewall. The tire diameter didn't change, which _MIGHT_ impact mileage.

Be very, very careful about going with a wider tread. This increases the rubber area exposed directly to the line of motion and can easily impact mileage. Also, there are some reports of wider tires extending out far enought to impact the edges of the wheel wells when going over bumps. This would be a very, very bad thing.

There may be some better things to do to improve your mileage than changing wheels and tires. What are you getting now and where do you want to be?

Thanks,
Bob Wilson

Re: Bigger Rims Better MPG?
 

I believe the Touring models do get a bit less than the standard model. Some Japanese folks with the Touring edition swapped out their 16s for 15s.

Re: Bigger Rims Better MPG?
 

51 is my average, which Im very happy with, considering what most people are getting in their non-hybrids. I watch my monitor constantly so it's hard for me to think I could get any better. Is that low to some of you guys?

I was just trying to figure that -in a mile, a bigger wheel will take less rotations and a smaller wheel will be more. Thats the only thing I was going off of with the better mpg on bigger rims. Otherwise I don't know much on physics and all that...

I saw a prius with nice wheels on it and I was thinking about getting some. However I don't want to change wheels if it's going to dramatically hurt my mpg.

I have a 2008 prius -package 6 if that matters

Re: Bigger Rims Better MPG?
 

A larger -wheel- (the aluminum part) will result in a heavier wheel/tire combo. Heavier will decrease the mileage.

While your thoughts of a large dia. wheel turning less are correct, it's the combination of the vehicle driveline design and the wheel that matters. The Prius is optimized for the overall diameter of either the 15" or the 16" combination (they both have the same overall diameter). Because the wheel weight goes up faster by diameter than the tire weight comes down due to sidewall height, the 15" combo is lighter than the 16" combo.

Now, if you wanted to drop the wheel weight to get better mileage, Volk Racing has come out with some really nice wheels for the Prius that are about 30% lighter than stock (same size). They are available in 15" and 16" sizes, 15" again being lighter.

CE28 ECO DRIVE Volk Racing Prius only Wheels
15 inch: 4.6kg (10.1 lbs)
16 inch: 4.9kg (10.8 lbs)

Toyota OEM Rim
15 inch 6.5kg (14.3 lbs)
16 inch 6.9kg (15.2 lbs)

They aren't particularly expensive compared to other good quality aftermarket wheels, at around $400 each or $1600 for a set. They also have a lot of "bling". ;)

Re: Bigger Rims Better MPG?
 

You're doing very good. Take a look at the average for your model Prius, 47.5 MPG, and you are doing about 8% better than the average. Come the warm weather, you'll do even better.

You have a great car and I would recommend getting a little more experience before looking at changes to the running gear. Some of the tricks in the Prius FAQ could help; recording your mileage to track progress can help; for now, enjoy the car and puzzle out how to improve operation of what you've already got.

Bob Wilson

Re: Bigger Rims Better MPG?
 

Good Day Tideland Prius; May I inquire where you got the JDM Prius interior footwell lighting? and the LED licence plate lights?

BTW; I own a 2008 Prius Touring and currently average between 45 to 49MPG.
Regards, Robert

Re: Bigger Rims Better MPG?
 

It appears you are getting decent MPG as is. I wouldn't waste my money on a new set of rims/tires. Your biggest factor going against you now, is weight. If you want to spend money, see if you can replace some components (hood, trunk, etc) of your car with CF.

Re: Bigger Rims Better MPG?
 

I have a 09 Camry and I added 20's My milage wasnt affected at all. I get 39 mpg, but its also a Camry. I am supposed to get 34.