^^^^ Guys, just fvck and make up already. Geez.

 

I believe it was road & track that did an acceleration and handling test to see what size rims were the best all around for performance. The end result was that the 17's were the best all around performer. But then again this was on a bmw and none of the wheels were forged. Also a wider tire could help a lot more with acceleration, so there are quite a few variables to consider when testing this.

 

For one thing, going through snow is a whole different issue then traction. Of course skinnier tires will go through snow better, but has nothing to do with what I was talking about traction. So, traction isn't a moot point at all. However, I'm not a track guy so I can't comment on whether fatter tires are better for straight line race, but I do know that if it is stickier, it will grip better, and the launch will be better.

 

Yes and no I guess. Yes snow is a diff ballgame. But it's still a matter of getting as much tire on the pavement as possible. It's just that a skinny tire will "cut" though the snow to get to that pavement vs a wide tire that just rides on top.

 

duece duece's FTW!!!

 

I tend to NOT agree with this guy...but he's right in an overall sense if acceleration AND lateral grip is being measured. His readin comprehension just sucks. 18" is the happy medium (naturally) between 17" and 19" rims given that the overall rotational height and width must stay same.

on a 17" rim, you will get a higher sidwall height, with that you get sidewall flex. regarding it's weight and potential parasitic mass, it would be ideal for acceleration.

on a 19" rim, you'll gain parasitic mass because it's being pushed farther out. the trade off is smaller tire sidewall, less sidewall fled. better steering feedback and less fatigue vs the 17"

On the 18" rim, you'll more than likely get a well rounded performance of the two other sizes.

Now, the subject matter is regarding acceleration. the consensus is that - if mass is closest to the center, there will be less effort to rotate the mass. The RPM will move at a quicker rate (much like the RPM of the engine when you install a lightened flywheel).

The smaller the rim, the less energy needed to rotate it - thus quicker revolutions.

 

Or unwanted compromises of not going to the other sizes. Plus the overwhelming factor would be the specific tire and specific tire size vs the actual wheel diameter.

 

agreed. wider tires creates more friction. there has to be controlled conditions given before making a better questimate

 

true, it's give-take between all the sizes. that facter regarding tire size is also true, and a PITA. I couldnt find race tires to match the height of the 18" oem setup for 17" rims.

 

well we will see!!!!

-sean

 

couldnt have explained it better myself... although it still stands to argue that light weight 17's with great tires with stiff sidewalls to limit the amount of flex would be an ideal set up

 

There are some small ways of limiting sidwall flex on taller tires. Means of doing that is by getting a wider rim or narrower tires. The general idea is that the tread width is smaller than the rim to induce stretching when mounted. this causes the sidewalls to be preloaded in opposing direction.

My roadrace setup is 245/45/17 on 17x10 rims up front and 275/40/17 on 17x10 in back (looking to get bigger 315/35/17). I'm very impressed with it's turn-in. And because I drive with my rear wheels...rear flex isnt an issue to me, it's making them last. . their height is almost the same the 245/45 being slightly taller (unmounted), but stretching the tires brought the height of the front tires down just a little bit..possibly even with the 275/40 rear.

 

The factory 18s are not really any heavier than the 19s. They are basically the same weight. The 19s are not good for performance driving due to less sidewall flex and a rougher more jittery ride.

When your on a track or even the road, and make turns you definitely want some flex in that sidewall or you will be hopping all over the road. Reason why you will never see a low profile tire on a track car.

 

Not always true, i know in the SCCA world challenge GT series cars alot of them use 18" rims with profile tires down to 30 at times.

-sean

 

True most of the time. I raced as you can see in my avatar picture. 18s are fine on the G35. 19s are not a RACE WHEEL. Too heavy, too much mass to turn.

On the G35 the 18s would be best, or even 17s are better for race purposes. As my point, most people who race do not have low profile tires.