What is the peformance benefit of 19 inch wheels vs. 18 inch wheels. Other than looks, why do people upsize?

 

thats it...looks. they're heavier, it makes the steering heavier, and feel less responsive. But it looks 100% better.

 

Tire selection is not nearly as good with 19's either. If you track, this should be a consideration. Actually, even if you don't track this could be a problem.

 

Thanks. Thougt maybe I was missing something. Not sure why so many people buy a performance sports car and then slow it down and subtract from the performance by buying 19s, but thats just me.

 

easy...bling! get 2 sets 19 for show and 18 for go...

 

Doesn't the 997tt use 19"?
If the wheels have similar rotational mass, wouldn't the lower profile tires have some advantages in transient handling?

What are your opinions?

 

I've tried both, the car just flat works better with the 18's

 

Anyone try 17s? Taller sidewalls give you better feel (up to a point) and can improve at and near limit cornering by better "telegraphing" to the driver. Probably due to sidewall flex.

Many forged wheels are lighter than factory hollow spokes and even lighter than solid spoke and GT2 wheels (which are solid spoke). As much as 10lb. per corner.

 

With 19's you can fit larger brakes, but unless they have 2 piece rotors, that will also add weight.

 

Yes and No. You can fit larger brakes on some 18s. The larger brakes also don't necessarily add weight as the calipers are lighter. Unfortunately the calipers are not rotational weight so even if there is an even exchange in weight loss from rotors to calipers, the larger brakes could slow you down.... literally

 

#1 Many people buy performance cars. NOT many people extract anywhere near the limit of that sports car, and even with heavier 19's you arent losing all that much performance especially if you're driving on the street. The look factor will outweigh the small performance loss for many people. It's not like you're going from K24 performance back to K16's, you may lose 1-2 mph in a 1/4 mile if that, but the ride will be smoother and more responsive. Of course this also brings into play tire selection which is critical.

#2 Many custom 19 inch wheels can weigh equal to or less than stockers, so you have a bigger contact patch, less sidewall flex, and possibly lighter weight. Putting the biggest tires you can fit on a car works for drag racing, but that's about it, unless with the increased sidewall size, you are increasing stiffness by going to more track oriented tires with extra stiff sidewalls.

 

I think you guys will find this European Car article by Jay Chen to put some closure on this issue.
http://www.europeancarweb.com/tech/0...res/index.html

In his article, I captured a real good excerpt per Porsche Engineering ...."All the fuel and chassis control systems on the 996 Turbo are built and tested around the wheel and tire size and their corresponding rolling radius. Altering the standard size not only has adverse effects on the performance and handling but most likely could end in damaged drivetrain parts such as a broken front differential or viscous clutch damage (not a warranty matter). The weight of the wheels and tires is not a major factor." This just goes to show how dialed in Porsche's cars are out of the box.

 

Good article. Anyone that buys a 911 Turbo and chooses to put on 19's trading performance for looks, loses some of my respect as an enthusiast. Besides, I don't think 19's look right on 996's. 18's on the other-hand are just right.

Just my opinion.

 

My Kinesis F110's weigh less than stock 18" hollows if I remember correctly. They are 19x8.5" in the front and 19x11.5" in the back if I remember correctly.

 

I don't race 1/4 mile or on a road course, so I don't feel I have compromised my car's performance significantly with my new HRE 19s. I am not sure how much they weigh but I wouldn't be surprised if they are less than the 18" stockers I had on before.

In reference to the above European Car article, does that mean that once we start modifying our cars (like 98% of the people on this forum do) then we put our cars' systems and drivetrain at a great risk of damaging them? I am not sure I buy into that....