Bigger Diameter = Slower car???

[7amood5041]

I'm planning on buying new rims and some of my friends advised me against going for 19" because it will make my car slower. Is that true? if it is then how slow will i b? Will the width also cause any similar affects?

The diameter of the wheel and the new will will not differ alot, and the new wheel will definitely by lighter. But what will change is the profile, it will have to be smaller. could that be the culprit?

Thanks

[TR GTO]

Some people think you're just putting overly large wheels on a car. The fact of the lighter weight of the wheel should keep from causing any unwanted rolling mass.

[purplenurple]

My car felt a bit quicker with my 19s, but I lost about 5lbs per corner

[GTOsarge]

Think of the rear sprockets on a 10 speed bycycle. It might change things a little but not enough to notice. A taller tire will have a larger diameter to complete 1 revolution.

[DAH GTO]

I was told by John at CCW going from OEM 17" to the 505A 19" with the 245/35-19 front tire and 275/30-19 rear tire, the overall height of the tire is the same as the OEM 17", 25"

[JDolan]

I wouldn't worry about it making you slower because its very negligible.

[Hendrix-Engineering]

I was told by John at CCW going from OEM 17" to the 505A 19" with the 245/35-19 front tire and 275/30-19 rear tire, the overall height of the tire is the same as the OEM 17", 25"

Actually i think 25.6 is the corect hight

[jon6.0]

Rotating weight kills acceloration. When I put my Ruff's on in 20x10 and 19x8.5 they were signifigantly heavier than my stock stuff and I felt the car go slower. If the new stuff you get is lighter than stock you will feel the car be snappier and quicker.

[ShelbyGoat]

Do you road race? Drag race? Auto-X? Serious street racer?

If not, I wouldn't worry about it. My 19" CSL's are looking good all day everyday...

[Choosetoride]

bigger diameter = your car has more miles on it than it says it does.

[MoNsTeR]

The only thing i hate about my 19's is the sidewalls..Im always dodging pot holes daily..

[7amood5041]

Thanks for the input guys,

So the most important factor is the weight of the wheel, not anything else. If it is heavier, more power is needed to rotate the wheel.

Not to go off topic or anything, but could the width also make the car slower?

[Summerwolf]

width adds weight, bigger tires more weight. there is a tradeoff in everything.

[jon6.0]

bigger diameter = your car has more miles on it than it says it does.

That's backwards. Bigger=slower mph indicated.

[itslow]

bigger diameter = your car has more miles on it than it says it does.

That's backwards. Bigger=slower mph indicated.

You need to work on your reading comprehension. ;) A larger diameter wheel will result in a speedometer that indicates a slower MPH than actual (you [jon6.0] have that correct), which, in turn, means the car is actually traveling farther than the speedometer/odometer indicates (which is what Choosetoride posted).

Larger OD - Speedometer/Odometer read less than actual; car traveling faster/further than indicated.
Smaller OD - Speedometer/Odometer read more than actual; car traveling slower/less than indicated.


RE: original post;

The new wheel may be lighter than your stock 17/18", but it will likely have more weight further away from the hub which will increase the amount of rotational inertia. That inertia will hinder acceleration. However, for anything but drag racing, it is pretty much inconsequential. And if you're serious enough about drag racing that the reduction is of great concern, you'd be going the opposite direction and using track-only 15" wheels with drag radials.

In summary, if you're driving the car on the street; the 19" will work fine and you won't notice and SOTP change in performance.