Ideal Tire Size
 

What do you think is the perfect tire size for street performance on

Turbo Twists 18" Front 7.5 ET45 and Rear 9" ET52

I am upgrading from 17" to 18"s this summer and am looking for the perfect style, look, balance and street performance. Probably will get either BFG or Michelen Summer Tires

Front: 225/40/18
Rear: 265/35/18

Those are the OE sizes for 18" wheels.

Take a look at the Firestone Indy`s before you buy. I run 18`s 225/40 265/35 .Really like them. Quiet and good in the wet.Nice price too.

For "street" performance tires look at Pilot SuperSports. Not low cost, but simply a great tire. For lower cost options, Sumitomo HTR ZIII and Hankook Ventus V12

Front: 235/40/18
Rear: 265/35/18

Is what I run to minimize understeer, the 235 fits fine on OE wheels which have ET 50 offset

You need to be a little careful with 235 on the front, it can rub the fender liner at full lock
depends a bit on what actual tire you use. Check the diameters and see where you are

I put the Hankooks on +/- 8 weeks ago. Very pleased with them and paid $630 all in.

What is the "Ideal" tire size???? Well what the engineers put on the sticker under the hood of course. Personal preference may vary.

The manufacturers put the most economical; I'm seeking inputs from a variety of perspectives vs "personal preference" from engineers.

Inputs from everyone have been informative.

Cheers

Ummm. No. Porsche engineers choose tires based on desired handling and safety for the masses such as desired understeer characteristics. Porsches engineers even specify N spec tires to obtain these ratings, which may be overkill for some personal preferences. I'm not saying a manufacturer such as KIA doesn't choose the cheapest (economical) but Porsche engineers have certain performance objectives in mind when they specify sizes. If you read the post above concerning the 235 tread width it is done for personal preference which is a desire to tune out a little of the understeer.

You do need to look at actual tread width. It varies a lot from tire to tire.
You can have 225's that are actually wider than 235's

Sure, and Continental's will suit that need for German vehicles at a cheaper cost than Michelens which are more popular on the performance aspects which many indorse.

Under steer is not all negative either ...