Why go from 17” wheels to 18”?
 

Hi all. Just wondering what the benefits are from 17 to 18 inch wheels for an S other than looks. I found a set of Porsche 18s wheels for $600. No tires, just wheels. Is there a performance benefit and is it worth the extra cost of wheels and bigger set of tires? The tires on my 17s need to be replaced anyway so nows the best time to w the change. Thanks.

The drawbacks are a harsher ride and more expensive tires.

18" will compensate some from lowering the P car to status quo

Better looks.

Doesn't the S need the 18s because of the larger front brake caliper or do 17s have enough clearance?

I have 18s but I would think that 17s would handle better and tires would be a bit cheaper

Looks mostly. The 18's fill the wheel well more than the 17's. I have a set of 18's I run normally and 17's I use for autocross. I can't tell a huge difference in the ride quality but I'm sure there is a little bit as the 17's put more space between you and the road.

S models are fine (and were standard wheel) with 17's. It's 16's that don't clear the calipers.

But with 18’s you can get Bridgestone RE-71’s on! Not on 17’s.

Serious question. Is that a good thing? I thought most prefer Michelins.

No Most Dentists prefer Colgate over Crest

Oh know, I feel a tire thread starting

Most doing autocross prefer the RE-71’s. Not looking to start a tire debate.

A lot of autocrossers prefer the RE-71’S. Not looking to start a tire debate.

what you talking bout Willis??

Re-71's and lot of other trackable tires come in correct 17" sizes. I and many others have been running RE-71's in 255/40-17 and 225/45-17 for years

17's fit a S no problem
17's are lower cost

I had to upgrade to 18's when I did the bigger brake upgrade and aesthetics was a bonus.

16's with the correct offset would have no problem clearing the S calipers. The problem is nobody makes them.

My favorite tire place, Costco, doesn’t carry the RE-71s for the front! Too bad as Bridgestone are on sale.

And, usually, the typical compound used in 18" tires wears faster than the typical 17" tire compound, as 18s usually have a higher performance rating.

Really???

Performance rating has nothing to do with tire diameter.
I would think the compound in a given tire model would be the same regardless of size.

I run 235/40/18s on the front from Costco. They weren’t listed on their site but I could order them at the store. I won’t let them mount them though.

And weight... Stock to stock 17" is lighter with tire mounted.

Thanks for the info!

I’ve got a set of 17” Boxster II wheels I bought and the 18” Lt Alloy Carrera wheels the car came with. With OEM Pilot Sport N3 tires mounted the front 17 and 18”s weigh the same. The 18 inch rears weigh less than 2 lbs more than the 17’s. Every lb counts with unsprung weight but gaining an inch diameter in rim is offset by losing a half inch of rubber sidewall on both sides of the tire. For street driving there is no difference but an extra half inch of sidewall to protect your rims from potholes is nice. On the 18’s I just replaced the tires with Pilot Sport 4S tires bought at Costco and mounted by them on my refinished wheels. They do a great job at Costco and with the deal they had on Michelin’s last June, similar to their current Bridgestone deal, I was out the door for less than just buying the tires from Tire Rack. Costco is the only tire place I’ve seen that gives you nitrogen for no charge and religiously uses a torque wrench for the final tightening. YMMV.

If you are buying Bridgestione tires, get the best price you can from COSTCO, or online and then go to a Firestone store. They will match the price and if you use a Firestone credit card, you get an additional 5% off.

Another place for a deal is Summit Racing. They will beat any verifiable priced. IIRC, they often have free shipping as well. I have played that game with them several times on brake pads and otherr parts. My last set of Nt-01's too came from them. I found my tire size mispriced on Amazon and Summit beat it by a buck and I got them in 2 days

Okay, I stand corrected... 18" light Carrera wheel is well, light as 17". But for most cases going bigger results in heavier.

Anyway factory does not recommend 18" wheels for 1997, keeping my options plain and simple.....

Yes, you can. Just go with the 225/45-17 instead of the 205/50-17. its 2 cm wider, but fits the rims and doesn't rub. As a bonus you get slightly better grip cornering because of the bigger contact area.

(Edited. the width to sidewall ratios were wrong in the original)