Best Handling Wheel 18" or 19"

I am down to the wire on any order changes. Dealer tried to wangle 19' Carrera Sport Wheels through a 997 order, you can get them now with a 997, but the rear wheel is too large at 19' X 11' versus the Cayman version at 19' X 10'. So from a handling perspective with PASM , do you go with one of the other 19s or stay with the 18' Cayman wheels. There seems to be more than a suggestion in the Porsche marketing literature that the stock 18' wheels are very light. One concern I have with the 18' now is whether the suspension will be to soft with PASM in the normal mode. Thanks, JHellow

If you go 19', Sport Designs are the lightest 19' current available, but hard to keep clean. /fckeditor/editor/images/smiley/MWPX/teeth_smile.gif

From a handling perspective, the 18 inch stock wheels and tires are a fine setup with the Cayman S chassis and 295 HP engine. The 19 inch wheels fill the wheel wells and the 5 spoke wheels look very agressive. However, the Cayman S does not need the extra rubber until it gets 50 to 100 more horse power and the quality of the ride will be compromised by running the 19 inchers. I think it comes down to a trade off between looks and ride.

I have to assume Porsche knowsthat 19swork better because the Carrera S comes with 19s, where the regular Carrera comes with 18s.

This is a whole new area as the Cayman will already have stiffer springs, shocks, roll bars, etc., so I don't think anyone has a definite answer yet on what suspension combinations will 'feel' like. IMO I don't see any reason to go to a 19' wheel except for looks at this point. IMO 99% of the people on this board will not be able to drive past the grip offered by the standard 18'wheel/tire combo on the street......including myself.

The Prosche Cayman engineers got the Michelin PS2 18 - inch Carrer GT - like wheel combination setup perfectly for the Cayman S . Mechanical grip, which the 911 has long relied on for handling/performance, is not as critical in the Cayman S because of the near perfect Cayman S chassis. So perfect is the chassis/tire setup on the 18 inch wheeled Cayman S that getting the car to go into a drift takes some skill, so stuck to the road the car already is. The longer one waits to place an order the more likelyone will get Continentals or Pirellis on their Cayman . The Michelins will provide the best combination of grip and ride quality. Moving to the 19 inch wheels means you will be moving to a less sorted-out combination of chassis/ride compliance. But if your self esteem is measured by the size of your wheels, then by all means get the 19 inch wheels or see if you can find some after market 20 inchers.

There are no decent track tires in 19' sizes at the moment. Also, there is something to be said about the difference between handling and roadholding. Roadholding is the maximum speed at which a car can take a given corner before its tires fail to keep it on line. Handling is how a car responds to a driver's dynamic inputs - how it feels to drive. Wider tires may (or may not) provide higher limits of roadholding in some circumstances, but they almost always contribute to worse handling, in that there is less feedback and modulation (controllability) possible as the cornering limits are met and exceeded. Bottom line, smaller tires are ofter more fun and they allow the car to accelerate faster due to less unsprung and rotating mass... Edited by - grant on 09/30/2005 11:30:02 AM

Thanks for the replies. I am not all that concerned with looks as I think all of the wheel combinations with the Cayman look great. The RT article stats for a Cayman with 18s compared to a Boxster with 19s, indicates that in seperate tests the Boxster S did a good bit better through the slolom and on the skid pad. Other than a change in conditions, the only thing I could surmise was the 19' wheels on the Boxster gave it some advantage. I suspect that the Cayman and PASM for that car are optimized for the stock 18s, but who knows? I suspect that the Carrera Sport wheels also are very light. JHellow

One needs to be careful whenselecting the ideal wheel/tire setup for a Cayman S and basing that decision on what works for Boxster S . The chassis in the Cayman S is so muchstiffer than the Boxster S and so one would expect the Boxster S to do better with more rubber on the road, and thus more mechanical grip,in a slalom test versus a Cayman S . Do decide if you want to configure your Cayman S for the track or the road. Also note that Porsche will not use PASM on the upcoming 997 GT3 , opting for a revised sport setup. See: http://www.autoweek.com/article.cms?articleId=102425 If you are looking for the best setup for low lap times for a Cayman S on the Nurburgring's North Loop, then PASM may not be the best choice either.

True, for any track use, buy the stock suspension (not PASM) and replace with coilovers. Many types are adjustable, so you can set up for street or track by turning some knobs. Much better performance than PASM.

What does a set of coilovers (PSS9) cost? Just curious, Thanks.

approx. $3300.... http://www.evoms.com/p%20993tt%20pss9.htm

Mpollard: Yet Rorhl did his 8' 11' at the RIng with PASM and 19's. One would think if Porsche was sending a car out to the Ring to set a time, they would do it with the best available factory configuation at their disposal. Rorhl claerly believes in PASM and I think in one article suggested it saved at least 3 seconds on the Cayman 's time. I will track the car occasionally. Perhaps my original question cannot be answered until we have cars to drive. I have reviewed Porsche 's graphs of the effect of PASM on the suspension at both normal and sport settings. The non- PASM suspension sits right in the middle of that graph. Will the 18's be too soft at the normal setting with PASM for every day driving? JHellow JHellow

If I'm not mistaken though Rorhlactually liked driving the car better with the 18's......lot to be said for that also. If you drive the 'Ring every day to work then the 19's may be to your liking.......otherwise they may just be a waste of money. Your call. I'm notquite sure but I also believe the Cayman that did the 8.11 was equipped with PASM, Sport Chrono, 19's and PCCB.........so who knowswhich option contributed the most to the3 second improvement over a lighter optioned Cayman. I'm not trying to bag on any of the above options........but we're talking about a 1% improvement here in lap time for a whole lot of $$$$.......anywhere fromabout 3%to 18%the total price of the car! Again, your call. Just remember, Porsche wants you to spend more money on options whether they truly produce better numbers or not.........so they will trot out Cayman examples loaded to the hilt every chance they get.

Atlas: Thanks for putting it in perspective. At this point I am sticking with the 18s, PASM and Sports Chron Plus. I have over optioned the car as it is. I am a sucker for electronics and seats. I am going to get the 18s painted bt Wheel Enhancement to dress them up a bit. Has anyone elso commented on how much the stock 18s look like the wheels BMW puts on the upper end 5 series? In fact they look like the same wheel. JHellow

JHellow - I think the 18's with PASM willprobably be thebest combo.No one here really knows how a Cayman 'feels' just yet....... tough decisionswhen you can't compare. When I drove a Boxster S with PASM and 19's it felt a little too hardin Sport (for normal street driving) and a little too softin Normal.....it would kind of float over bumps.Then again the Boxster S is setup a little softer than the Cayman is from the factory.......but the Cayman has had it's PASM settings tweaked also. This is one reason I'm not too fond of 'adjustable' suspensions......thequestion for the Cayman is.......do you drive around in Sport all day long and only use Normal on bad streets?.....or do you drive around in Normal and only use Sport for thetrack? I have gotten manydifferent opinions about the stock 18's......some say they look great, others say they look 'cheap'. I went with them as I happen to like the look........the BMW refis a new one on me. One thing for sure, I have used Wheel Enhancement before and they are great!

These look similar to me to the stock Cayman 18'. JHellow <input type="image" src="http://www.bmwusa.com/NR/rdonlyres/B8C29910-BEBA-4262-AE83-5450427490D7/0/star_spoke_122.jpg" />

My question is, as both the 18s and 19s use the very same tire width (235 and 265) will there be such a large difference in outright grip. On most marques the wheel upgrade options normally deliver much wider rubber. That appears not to be the case on the Cayman . Yes the rears have slightly wider metal, but the rubber is still the same size. My very basic understanding of the whole wheel/tire thing is something like this: Narrower rubber provides less grip than wider rubber. But their charecter provides softer 'limits' in handling. Predomenently that 'break away' of grip is more predictable, exploitable and controlable. Conversley, wider rubber offers high grip, but at the limit the break away is more violent and more difficult to predict and control. Smaller diameter wheels with a larger side-wall are more complient, offering better ride quality. They also allow more lateral movement of the wheel in relation to the contact patch of the tire. This adds to the feeling of more controlable break away as traction/grip is lost more progresively as the tire wall flexes under load. Again, conversley, the larger diameter wheel/lower-profile side wall combination potentially provide more outright grip to a point, and then adhesion is lost rapidly and with less indication. Is this basiclly right? If so, then a change from 18 to 19 would appear less detrimental with the Cayman , as the contact patch is actually very similar, than other marques where swapping from 18 to 19 often means goind from, say 225 to 255 widths. Jack

see the Best Motoring - EVO IX episode in which there is an interesting test between 18 VS 19 (but different tyre width). However they said that a normal driver will be faster on 18 than 19

These are the main reasons why most that have test run a Cayman seem to prefer the 18's over the 19's.....the grip is about the same, but the break away is moreprogressive with18's instead of the on/off nature of the 19's.

I think Atlas is right, but I went with 19' anyway. Looks do matter, and 19s look better. Like he said, who knows which of the options contributed to fast time, so I got 'em all! I'm a sucker.... And I don't mind contributing a little to the Porsche R&D find. I'm glad this stuff is available....

i am going to go with 19, and besides are any of you really going to take the car out on the track, imo no

I will definitely track my Cayman . Since no one really knows the 'hot' setup, I've foregone PASM and stayed with 18' wheels to start; modifications will be made as needed and with experience accumulated over time. I would expect many others to track their Cayman 's as well, but maybe your point was that initial buyers may be reluctant to track their new cars and leave it to 2nd owners to really hit the tracks.

It is just a shame that not more 18' options are available to choose between. The 19 certainly look better, in design as well as 'size'. So for me, 19 are going on as the 18s just don't offer the pesence that the car deserves. And I will be on the track with my car, no matter what shoes it's wearing. Jack

I'll be sticking with the 18's on mine... The PASM debate sounds more interesting though. Be interesting to see what the UK road testers think over the next few days when the relevant magazines come out (evo, Car, Autocar). These guys know their stuff IMO. And I'll be tracking mine too/fckeditor/editor/images/smiley/MWPX/drive.gif Stunters (Jan build, 1 March 06 delivery, provision spec Arctic Silver, Xenons, Climate, Sports Seats, Sports Wheel, PASM, Sport Chrono, HFS, Wheel Centre Crests, Crest on Seats, BOSE, 6CD....gotta draw the line somewhere!)

Standard 18s look very much like the wheels on the Mazda RX8, gone with 19' for the Cayman have the 18' on the Boxster at present.