Increasing Gas Mileage With Taller Tires? Options

[D-Man]

It always pisses me off when my car is rated 27/34 and I get 25 in the city.

Buy sandals, apparently your foot is too heavy.

[playr158]

wheels are not considered unsprung weight....you consider them rotational weight.
unsprung weight would only be the spring around your shock at a stand still

Incorrect. Read this: http://en.wikipedia.org/wiki/Unsprung_weight

glad you linked the article i quoted

read entire threads b4 clicking reply

This post has been edited by playr158: Oct 24, 2008 - 8:28 AM

[97GTinKC]

Wheel size alone can not be used as an indicator of weight. It all depends on the particular design, and there are better and worse ones out there. I would bet you can find 18" wheels with low profile tires that will weigh considerably less than the same overall height/width combo in a 15 or 16" wheel.

I am pretty sure you would gain fuel mileage with taller tires in a GT, (maybe not an ST) there is plenty of power available at highway speeds, I keep thinking I need another gear. But keep in mind- if you do change, it will throw your speedometer off so you may not be able to accurately calculate the actual gains.

My own mileage has dropped from a constant 29.9 mpg average to 27.5 ever since Missouri forced ethanol on us. This is what happens when you get government involved in technical/economic stuff. If I am adding 10% ethanol to the fuel and my mileage drops by 10%, I am burning the EXACT SAME amount of gasoline + the ethanol, so what have we gained in carbon emissions or oil usage reductions except to now drive up the price of food also?

[GriffGirl]

But it makes us tree hugging left wing liberals out here in Oregon so happy that you're spewing corn into the environment.


CORN not CARBON

[joyworks]

Well said 97GTinKC, those are my feelings on the subject as well. Now, can anyone tell me how large of a wheel/tire diameter I can safely get into the wheel well of my Celica without any rubbing? It has not been lowered. I assume it would dependent on tire width. I will probably go with a 205 or 215 on a 16" rim. Any wider, and like people said earlier, it will negate any fuel savings.

[RickJamesBish]

It always pisses me off when my car is rated 27/34 and I get 25 in the city.

Buy sandals, apparently your foot is too heavy.

See my other thread. Don't all auto ST's get similar mileage?

[97GTinKC]

I'm going with 215/50-16 next time in place of the 205/50-16 on there now. Probably the BF Goodrich Traction TA again.

[alaNi]

touche what octane do you guys use?

[playr158]

Wheel size alone can not be used as an indicator of weight. It all depends on the particular design, and there are better and worse ones out there. I would bet you can find 18" wheels with low profile tires that will weigh considerably less than the same overall height/width combo in a 15 or 16" wheel.

this is very true. I can produce 18s that weight a LOT less than a set of 15s.....now tell me who on this site will put enough $ into their wheels that they'll buy $2000+ rims (alone) for some quality LTW wheels over your $1000 18" set of HP racing/AXIS ect.

yes i'm being bad and assuming the OP like 90% of this car culture will buy generic wheels.

[GriffGirl]

It always pisses me off when my car is rated 27/34 and I get 25 in the city.

Buy sandals, apparently your foot is too heavy.

See my other thread. Don't all auto ST's get similar mileage?

Nope, apparently not because I average 30 mpg and I know there's not THAT much of a difference between auto/manual trans.

[RickJamesBish]

Well, that's mad annoying...I'll just have to look into commonly fuel-sapping problems, since there's obviously something wrong.

[GriffGirl]

Well said 97GTinKC, those are my feelings on the subject as well. Now, can anyone tell me how large of a wheel/tire diameter I can safely get into the wheel well of my Celica without any rubbing? It has not been lowered. I assume it would dependent on tire width. I will probably go with a 205 or 215 on a 16" rim. Any wider, and like people said earlier, it will negate any fuel savings.

215 is totally fine, and probably a better choice than 205. You can go up to 225 I believe w/out any concern of rubbing, and I don't believe either one will affect mileage. I'm running 215/40R17 on a manual ST and get 30 mpg on average, that's with stop and go and highway combined.