Does Size really matter- wheels and tires

chilidipper

New Member
Jun 28, 2010
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Hey All, FNG out of CA. Just bought my first Stang. Need skins, running stocker wheels. What I am trying to find out is.... IS there an advantage to running larger diamenter wheels (19", and 20"s)

Seems to me that it is a disadvantage to have less sidewall for ride comfort?

2nd question- going from 235x55x18 to 275x40x18
How much i am going to lose on MPG?
 
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Larger rims have no advantage other then looks. from 235 to 275 especially on all four corners you will notice a drop in MPG due to a width increase of almost 2 inches, that is a lot more tire on the road that causes more friction. Perhaps 2-3 MPG maybe more depending on tire choice.
 
Does Size Matter

I went from the stock 17" to 18" because the outer diameter of the wheel and tire is the same as stock (27.5") with 255/45/18 front and 275/40/18 rear...

I did not experience any change in MPG but car had got greater handling and braking due to a bigger wheel/tire combination...

Torque is better because I was smoking the 17" so bad but that could be a result of a wider tire in back...

20" look cool if you want to show your car but as for performance, stick with a setup diameter that is close to OEM stock...

Dave
 
I use Tirerack.com to look at the specs. of the tire (diameter & rotations per mile) to compare sizes. If you look at the sizes of the tires you are quoting the 275's are shorter, this will give you a stiffer ride. A friend of mine used that size and burned them up in a hurry. Try something with more sidewall for comefort, in other words try to match the height size to OEM. If you change the diameter of the tire too much it will change your speedo accuracy, but then that gives you a reason to get a an SCT power flash (or something similar) to tell the car the tire diameter.
 
Great advice, I love the look of 20's , but don't like rough ride

Not to mention rim dings from pot holes. I happen to not like the hard rubber wheel look myself. I go with that works the best. Taller sidewalls help in Drag racing. Shorter sidewalls help keep the tread flat in the corners. But there is a limit to how far that benefit goes.
 
I went from a stock 235/55/17 Pirelli P-Zero to a
18 x 10 rear with Nitto 285/40/18 555 Extremes and
18 x 9 front with Nitto 245/40/18 555 Extremes
and noticed a big difference in handling from the stock 17" Pirellis to the 18" Nittos, couldn't be happier, the ride is alittle harsher but not enough to brother me, I don't think I would want anything bigger then a 18" wheel on my car, can't say that my gas mileage has changed.
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I went from the stock 17" to 18" because the outer diameter of the wheel and tire is the same as stock (27.5") with 255/45/18 front and 275/40/18 rear...

I did not experience any change in MPG but car had got greater handling and braking due to a bigger wheel/tire combination...

Torque is better because I was smoking the 17" so bad but that could be a result of a wider tire in back...

20" look cool if you want to show your car but as for performance, stick with a setup diameter that is close to OEM stock...

Dave

275/40/18 is actually only 26.66. A better choice would have been 285/40/18 which is 26.98.