Cole

They also like carburetors and iron engines!

MjRocket

Seems like an *** backwards question to me.

Why NOT? If thats what he likes and was able to make it happen?

And to be honest it looked great, his car drew quite a bit of positive attention.

I mean why do any of us do half the crazy stuff we do to these 25+ year old cars? Obviously because it makes us happy.

Thats all that matters

worf928

You threw out a bunch of stuff not related to overall diameter. I tried to disambiguate.

Those are not race cars. Lamborghinis etc., are just as market-oriented as a Camry. Just a different market.

At this point it's the consumer market that is driving suppliers to push lower-profile tires into racing. Not engineering.

Obviously. Else these 20" wheels and tires would by flying off cars right and left.

You guys missed my point or I didn't make it very well: You have to consider the whole package unless you are interested only in looks.

That's actually another, very good point. The tire weight is out at the far end of the lever arm. Take a 16" wheel and put a heavy tire on it and overall performance will be worse.

Great. You have a good combination then.

I run taller- and wider-than-stock wheels too and they do work better than stock.

I've improved the handling of many 928s, as far as the drivers are concerned, by having them get rid of huge, too-heavy 'bling' wheels in favor of a wheel/tire combination much closer to the design parameters of the suspension and car.

The last example was a '90 with 8x18" and 10x18" turbo-twist replicas. Those wheels with PZero tires were far, far heavier than then D90s it came with. It's now both faster (objectively) and handles better (subjectively) with 16" OE 928 wheels. It certainly looked The Bomb with the 18"ers. But, it drove like a truck. The owner was more interested in how it drove than in how it looked.

worf928

Absolutely. Modern tires are great. But, IMO there is limit (it's not a well-defined line though) and I'll bet that limit is somewhere in the vicinity of 70mm of sidewall for a 928.

In New England that limit is closer to 90mm unless you like getting your rims straightened twice a year.

The F1 guys pitched a royal fit when Continental (IIRC) said that they'd only supply F1 if they went to 17"+ wheels. And they wanted to supply those tires because they were more relevant to the consumer market.

Porsche's engineers made a judgement though. They prefer some sidewall.

Cole

That really isn't a true statement without the following qualifiers.

1. .....based on early 1970s technology
2........based on early 1970s tire size manufacturing abilities, cost and technology.
3......based on early 1970s knowledge of suspension/tire dynamics and materials.


Based on your logic Porsche Engineers also preferred cassette tapes!

Cole

....it should also be pointed out that the "Porsche Engineers" were the first to really " prefer LESS sidewall and set that example when they put 16s and later 17s on the 928 to begin with.

Remember that the norm back then was 15" and smaller. The same generation Ferarris were still running 15s.

worf928

Why don't you re-read my post above wherein I provided an example of 2014 Porsche tire sizes?

TL;DR: even in 2014, the largest-diameter OE wheel from Porsche has more sidewall than a 928 would have with 19" wheels.

Cole

....and the 1971 Porsche 917 Race car had 17" rear wheels!
....and the 1987 Porsche 959 as an example came with 17s. (Ahead of its time again)

Porsche was leading with larger wheels for a long time. I'm sure choices had to be made about the consumers ability to buy tires too.

Cole

Eh....not really. I just checked the size of 2014 Turbo Tires against my 19s.

Rear is -.12" less and the front has .14" more sidewall. Hardly argument worthy differences.


Rear.


Front.

worf928

What size tires are you actually running? Your first post shows a different front tires size than you show in the above capture. If you are indeed running a 255/35-19 on the front as shown immediately above and not a 255/30-19 as in your first post then you have virtually the same sidewall height and not less and I stand corrected. You are of course at the very limit of what will fit in the wheel well; it's the same overall height I run on the front and everything has to be just right for no rubbing.

Andy Kay

So for the guys that have moved to an 18 or 19 inch wheel, how do you like the ride compared to the earlier 16 or 17 inch? Better … worse … harder … Keep it simple please ... I'm a simple kind of guy!

I'm looking for the most comfortable and quiet ride!

Cole

The first post was definitely a "guess" at what I thought was on the car.......which you can see from the way I posted it. (I wasn't at home with the 928 when posted)

The second post I was actually at home and checked the tires to make sure of the size. (no rubbing fwiw)




I found my 19s to be a much better ride than the 16s I took off. Its a very comfortable ride. That doesn't mean that all 19s will ride better than all 16s. In my case the tires that came off were about 20 years old.

FWIW, I also have a 951 on 18s, a Cayenne Turbo with 18" winters/22" summers, a T4 Eurovan on 18s, an C5 S6 Avant on 18s and I think the 928S4 rides better than all of them. Nothing harsh about the ride at all.

Bigfoot928

still break loos at 60 in 3rd gear.... I suspect that will get worse with the corvette 6 speed trans...... going in soon...

Cole

All part of the reason most high powered modern Porsches are AWD and traction controlled.