i heard that 18" wheels make your car slower. But physics dictates that the larger the wheel the slower u have to turn it to gain the same speed as a smaller wheel.
so unless the 18" wheels are made of solid iron they should make your car travel faster.

So whats the best answer do 18" wheels slow u down ? are 17" wheels better?


Modified by tintin11 at 5:46 AM 6/3/2003

 

You have to consider the weight of the rims and the profile of the tires (overall diameter). Just stating 18" rims will make you slower is not accurate.

 

the real concern with larger wheels and acceleration is where the weight is located. if you have two wheels that weigh 20 lbs, one a 15" and one a 17", it will be easier (and faster) to launch the 15" wheel because its weight is closer to the center. bigger often looks better, but lighter is always best.

 

18" rims will destroy any thoughts of your cars acceleration, to give you an idea, your looking at like 7 tenths to possibly a full second, ive tested it, i ran on my stock 15s ran consistent 14.1s, then ran with my freinds 17 " rims, and my times jumped to 14.5s...and my traps were slower, the larger diameter will give you a higher top end because its affecting your final drive ratio, kinda like lengthing your gears, but your acceleration will suffer..and its the fact the your moving all the weight farther from the center..think if you had a 1 foot pole with a 5lb weight on it, lifting that...then put that 5lb weight on the end of a 10 ft pole, and its much much harder to raie..your going to be the fastest with a stock size rims, thats as light as you can get it.....and the larger wheels and tires will give better handling due to the much stiffer sidewall and larger contact patch

 

There is so much speculation about rim sizes affecting acceleration, but some of it seems so unexplained.

Let's compare a 15 in rim with 205/55/15 tires with a 17 in. wheel with 215/40/17 tires. They are virtually the same wheel and tire diameter.
My question is this; Does having 2 inches MORE "rim" and LESS "tire" differ that greatly than a 15in wheel with MORE tire mass??-----to a point where it would affect quarter mile times by .7 seconds consistently? I would think there would be more to this than explained.

I understand that rotational forces act on a moment of inertia, that is not determined by only net mass: it is determined essentially where the mass is located on the turning object.

In addition, although I understand the concept that wheel diameter can affect acceleration as much as gear ratios can, then how come this isn't discussed as much? Could in theory 5th gen preludes change tire/wheel sizes to have smaller "gear ratios" and in turn keep up with their 4th gen counterparts? This seems too easy to be true.

Can anyone shed any light on these topics?

 

yes it would..look at a rim, the majority of the metal is on the outer partlike the cylinder itself..not the spoker or whatever...putting the main wieght father from the center can affect your acceleration greatly, ive tested it at a track on the same day with multiple runs got a very good average, and the 7 tenths was a higher estimate, but some if the bling bling wheels that look nice are heavy as hell..the best option you have is lightweight stock size wheels..for accleration purposes, why do you think drag racers run not only super light billit wheels when racing on slicks with super tiny light skinnes?, theres power to be made there..and Hondas arent Tourqe monsters to begine with so adding wieght to its drive wheels affects it much more than youd like to think