David A

Sport Auto in Germany tested a 997 3.6 with 18 inch and 19 inch wheels back to back and the car with 19 inch was slower by 2 seconds 0 to 200 KPH.
(125 MPH).

Le Chef

If that's caused by the extra weight of 19" wheels, what impact would 20" wheels have on performance?

David A

It 's because 19 inch have a bigger circumference ratio(bigger circle) than 18 inch.

dnp_now

Did it say anything about the differences in ride comfort?

Would a 997S non pasm get better performances with 18" wheels?

David A

19 inch gets a smaller side wall, so the ride is harder but they didn't talk about the 3.8

MJones

The 18 and 19's have the same rolling diameter due to the increased sidewall height of the 18's vs 19's
is 0 to 200 KPH meaningfull at all...Does anybody really care......what are the slalom speeds?

Fact:
The 997 that competes in the Grand Am GS class runs on 17" wheels, per the rule book.

rss997

I want 16's on mine if it makes me faster than your S....MJones!

Viken

No they don't. There are two reasons why 19's are slower. One is weight and the other is higher drag coefficient. A bigger footprint produces more drag and slows the car down..

FWIW, Porsche themselves tested the Boxster very early on with 16's, 17's and 18's. The car was significantly faster around Weissach on 16's than on either 17's or 18's.

PV

Any idea what the weight difference is? I see many people, report many numbers, but how much is the total difference in weight.

Porsche themselves report the difference in drag for the wheels: 0.01 (0.28 vs 0.29).

Viken

That would be aerodynamic drag.

PV

Yep, very important for: top speed (if drag limited), fuel economy, and more.

Of course the road resistance (total different thing) will also change.

What about the weight?

MMD

If that's true I'm getting pissed. It's like posers are designing this car for Porsche. All show and no action.

I read somewhere that the 19s were slapped on the S just for looks and to differentiate it from the non-S.

So I have a slower car, with a harsher ride, just so it LOOKS cool and this is totally fine with Porsche even though they try to sell the car with all that "no-compromise-in-performance" baloney in the brochures?

PV

The S is heavier and has more drag .

Viken

First of all, Porsche is making and selling cars people want. Second, the S has a bigger engine with more torque and horsepower. As such, an S with 19's can still be a bit faster than a non-S with 18's. If you do decide to buy a plain Carrera, just don't get the 19's on that car.

riotgear

Sell your 19" wheels and buy a set of 17" or 18" wheels and get over it.