For DD - 17" versus 18" ride 'comfort' impressions...

...during my search for M 030 info, I noticed some folks suggesting that the 18" rims actually ride better than the 17". On my 993's I actually felt that the 18" turbo rims and tires rode softer than the stock 17-inchers for some weird reason. I think my 993 18" rims had Conti's. My 17" stock 996 rims have Conti's and they seem to ride rather harshly - not complaining, but was wondering if it would make more sense to find a softer riding tire than to switch up to 18's. Any comments or observations ???

I thought you were selling your car?

Softer riding tires for a Porsche? Or are you talking about a Cadillac?

we didnt accidently think we just bought a Lexus..... did we? "but was wondering if it would make more sense to find a softer riding tire than to switch up to 18's" I just sold a set of 18" twists in very good condition for under $600/ shipped - you can find these locally for around $400-$500 would be my guess and if you wait, you can find a set with tires on them. Then just swap out your entire set, this way you can swap back....then sell the set you least prefer (or send them to me - i'll cover the shipping costs )

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...if I were offered 24 for it, I'd take it. But I think I'll just drive it for now

I drive my 996 every day on 18s, and the highway ride is excellent. It's sometimes hard to believe tha this is a sports car based on how smoothly it cruises. I think 18s are a good combination of looks and ride quality. I don't think I'd go up to 19s, even though some have.

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...do you have standard suspension or M030???

I have 18's no issues with ride quality, but than I get what I expect from a 911.

I have both 17" and 18" sets. The 17" are the stock 10-spoke wheels with Michelin A/S tires that I used as my winter tires this year. They were on the car when I first bought it with the stock suspension and I didn't care for them at all. The floating feel that so many on here have complained about was actually very unsettling, especially at higher speeds. I picked up some 18" Sport Designs with Contis and noticed a significant improvement in handling but the ride was perhaps a bit more harsh. After upgrading to the ROW M030 the float is gone but I don't appreciate any worsening of ride quality with the 18". It really feels planted now. I've had the 17" back on since Nov. '08. Much more confidence inspiring with the suspension upgrade. My Sport Designs are now being straightened and refinished with new rear Contis too. Should be back this week! To sum up my experience I would have to say that the overall ride quality is definitely better with the 18" and M030. The ride is softer on the 17" but you give up so much in handling you'd be better served to get a Lexus instead.

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+1

On my car, with the X74, my snow tires (on 17"s) ride noticeably softer than my summer tires (18"s). Probably a factor due to both the "snow-tire-ness" and the rim size.

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^^^ +996 +18 +PSS10s

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I have the stock C4S suspension, which I believe is equivalent to the M030. Someone correct me if I'm wrong on that...

^^^ Correct

On a 02 C4 cab, I have two sets, the 17" 10 spokes original, with Michelin PS and another set, "aftermarket" Turbo Twist, 18", with brand new Michelin PS too. Last week, I shifted from the 17" to the 18", there is a LOT of difference. the 17" are softer, the 18" puts you in a much more "contact feeling" of the road. If you have a wife that likes confort, ..keep the 17" ! (I have also a Cayenne S with air suspension, and ..now it has 34'000 miles in ..Comfort position !)

Too many variables to make blanket pronouncements. Tire brand and even tire pressure can make a huge difference. Ride quality is a result of matching tire sidewall characteristics with suspension characteristics. It's not so simple as saying 185/70-14s will make your car ride better. My C4S 18s rides vastly better than my 993 on 17s. Again, too many variables. Well, there is one hard and fast rule: Bilstein HDs ride like crap regardless of car or tire.

17" provides a smoother ride for DD. Handling doesn't suffer much if you compared aginst the same tire. This is street driving after all.

I just changed my 17s to 18s and I do feel that my 996 rides better with the 18s. May not be softer, but the car just seems to handle better. I went from michelin to sumi too.

On my 17" twists w/ snow/winter tires, the car feels much more bouncy compared to the solid, more planted ride of 18" twists w/ summer tires. I'm sure if I got summer tires for the 17" rims, the ride would firm up and feel more similar to the 18". But a taller tire is always going to have more "bounce". I'm thinking of selling my 17" rims and winter tires, since I rarely drive the car as it is, and never take it out in the snow. I was also thinking of selling my Potenza summer tires and switching to Conti Extreme Contacts for year-round fun without the switch to winter rims. Still un-decided at this point.

I stuck with the Porsche recommended 18" wheels for my winter tires. The fronts are the same size as the summer wheels, and the back tires are down to a 265 from a 295 (10" wheel vs. 11" wheel). I haven't tried them out yet, so I'm curious to see how it rides. I don't expect it to handle like it does with summer tires, but I don't expect it to be vastly different for daily driving at reasonable speeds. I'll report back in October/November!

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Let us know how you like the sumis. As you all know, you are never far from needing new shoes in these cars. I run 18" 275 Dunlops on the back in the winter and didn't notice much handling difference. The MO30 suspension is pretty stiff for a DD on our really crummy roads. I'm running PS2's in summer and have just dropped the rear tire pressure to 39. My back teeth are appreciating a little softer ride but the trade off is faster tire wear.

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I like the sumis so far. I have about 1000 miles on them, and my daily commute is about 50 miles each way. They have some hard spots in the morning, but once they are warmed up, they are really great. So far I would recommend them to others here. You really cannot go wrong for the price. As far as handling I really see no difference from the Michelin PS2 Rib, and actually think I have a little better grip. But that is probably due to the 17 to 18 switch too.