Coochas

I don't think we can fault Porsche marketing without faulting the marketing depts at Ferrari and Lambo as well: all modern Ferraris come with 19s or staggered 19 + 20, and with the exception of the Murcielago (18s) all the Lambos come with 19s.

RonCT

I was up early with the recycling truck - You'd think that with the nasty storm we got, they would have slept in - nope!

This is what I hoped for - a spirited discussion about 18 v 19 v 20 and why, how, etc.

Tire diameters are all pretty much the same. Let's call it 25.5" just to pick a number. So whether you run 18s, 19s, or 20s, your tire diameter is 25.5" How much tire you have on the sidewall is the question. The rotors are 15" no matter what - so no matter what, you are going to have a little gap with 18s, a bigger gap with 19s, and even bigger with 20s.

The engineer I spoke with was saying how when the 997 was developed initially, it was figuring 18" wheels and tires. When marketing pushed them to 19s, a few adjustments had to be made to be able to run 19s properly. I'm not sure what they were or even why there would have to be adjustments - but that is what I was told. I have no idea what was written in books about this and I think we can all assume that if the confidential history was there was dissent between engineers and marketing on 18 vs. 19, that they certainly wouldn't let it be published. Of course the literature will say the car is made for 19s, but of course then you wonder if all C2s are running on the wrong wheels

Of course not everyone wants an efficient car. There are multiple inefficiencies in something like a 20" heavy and harsh wheel - but if that's what people want, that's what they will get. Heck, look at Porsche's option list - it's a mile long. Me - I can count the options I got on one hand.

elh0102

I agree, and I do. I am a totally non-discriminatory bling-hater. Never assume that either good taste or common sense accompany money.

Edgy01

Hey! The options list isn't a mile long, only about 65 pages when I ordered mine!

The source I pulled this is Randy Leffingwell,--who wrote "Porsche 911 -- Perfection By Design." Radny interviewed the design team, to include engineering leads as well as the marketeers.

While the book is all about the 911 from the 901 days, it ends with the 997S / Cabriolet of 2005/6. What he states within the book (a good coffee table book BTW) matches what I had read elsewhere.

I have found with Porsche that they are generally the leaders in the automotive world when it comes to pushing tire manufacturers to their limits. BMW seems to lag. In a short time the rest of the world catches up to what Porsche is aiming for. I don't believe there's a bling factor with the 19s.

The handling that I'm experiencing is telling me that something is definitely right there. Perhaps the ultimate compromise is with the cabriolets, as they also have a softer suspension setting that the 997 coupes. Thus, the best world is a 997S Cabriolet,--which doesn't shake loose the fillings in my head, yet corners effortlessly. If you want severe stick to the 997S coupe or GT3 and someday the GT2. My money's on those showing up at the party with 19s.

Crazy Canuck

I've read it numerous, different places. Excellence I think was one of them. This was back in '04/05 though.

Suspension geometry HAD to be revised for 19s to work properly according to factory sources quoted in the above articles.

The decision to switch to 19s was controversial. Bling guys were for it, purists were not (like me). Sourcing 19s, riding in 19s over frost heaved roads, lack of selection of 19s, heavier weight etc. formed my opinion. 19s do, however, look better on a 997 because of the size of the wheel arches.

Crazy Canuck

That's the storyline I heard. 18s were engineered and sometime along the way 19s were requested by marketing and changes had to be made to accommodate 19" tires and their larger overall diamater with tire on.

Crazy Canuck

997 Turbo, 997 GT3, 997 GT3 RS all come with 19" tires as standard equipment.

I could be wrong but I seem to recall that 997 cups and 997 RSRs both come with 18" wheels. No benefit it seems to go to 19s.

nkhalidi

You know Ron, I used to believe that 18s were absolutely the way to go on the 997. But the more track miles I put on my OEM 19s with PSCs (GT3 sizes), the more I think the car is a-ok the way it is, and I'm not going to mess with it. I have enough issues getting the car around the track coping with all that weight in the wrong end; wheel/tire sizes and sidewall aren't the limiting factor in my speed.

Also, now that we have PSC and Hoosier r-comps in 19" sizes to fit, it's only a matter of time until we see NT-01/RA1, V700, etc in 19. I don't drive my 997 on the street enough to justify a second set of wheels, so I'm sticking (inadvertent pun) with 19s for all purposes.

That said, on my M3 street car (sees zero track time), I downsized from OEM 19s to aftermarket 18s because I wanted lighter wheels, more tire options, and a little extra sidewall. I also love the way lowered M3s look on 18s.

But on the 997, especially seeing how the track-hardened GT3 and RS come with 19s, I just can't bring myself to downsize.

Ray S

If not bling what performance advantage do 19's offer?

They are clearly heavier (than an 18" wheel of similar design and manufacture)and not necessary to cover the brakes. Furthermore, 19" tires offer no traction advantages over a similarly sized 18" tire.

The 19's are clearly bling. They offer zero performance advantage over 18's (only disadvantages).

Edgy01

As I'm not a Porsche engineer I can't tell you the reasons that Porsche chose to go to 19s on these cars. I'm not exactly short of HP so any weight on the wheels is not noticeable by me. (Perhaps my PCCBs offset some of that gain). I like the wider wheels and tires. Running 305/30-19s (stock) on the rear.

WCE

Key point to remember is the OVERALL diameter of the tires were increased by about 1" resulting in the same sidewall height with 19's as 18's on the 996 model. On the otherhand, most 996 owners will admit those cars ride better on 17's and handle as well also. Since disc clearance isn't an issue (997's rotors aren't even 14", I think), and PASM goes a long way in smoothing the ride, Porsche went with 19's for two reasons, they could without hurting the ride or performance AND bling!

kauai_diver

The 19" offer less sidewall warping when cornering hard, but due to the harder sidewalls they do suffer from radial run out some times called "wandering".

If your driving hard over time make sure your tires are slightly under inflated, thats why I got TPMS. Good thing now it's standard.

The other reason was the size of the calipers were increased for the S.

So I disagree that Porsche did this for the bling. Questionable performance improvements? maybe arguable, but not bling. Why not 20"s for the S? diminishing returns, practicality, reliability, ...

jnx

I was unaware of this, where did you obtain this info? Thanks

Ray S

To the best of my knowledge 18's will clear the 997S calipers just fine. Additionally, Porsche could engineer the car to have the same sidewall height for an 18" or 19" tire. For example, if Porsche engineers and test drivers deemed that the optimum rear tire was a 295/30 they could play with the gear ratios to take the 3.851% difference in the OD of those two tires (18" vs 19") out of the equation. In that situation the ONLY thing you gain with the 19" wheel/tire combination is weight.

Crazy Canuck

18s clear the calipers on an S.

These came today ... and will be mated in awhile with some R-compounds for track duty.