this inquiry moves beyond benz wheel and tire issues, but i would like to think that you will indulge me, here.

though i have a small collection of benzes[mostly dedicated to the work of bruno sacco], when i acquired my 1997 s500c[c140] and my 2006 cl500[c215] i found the michelins that benz selected to be less than what i wanted in tires.

i found the yokohama avid v4s the superior wet road handler and much quieter for the s500c.

and i found the continental extreme contact dws similarly superior to the factory selections for the cl500.

last year, i acquired a virtually undriven 2008 porsche cayenne turbo fitted with 275/40-20 bridgestone dueller h/p sport tires.

i have now driven the vehicle for 6,000 miles[total of 8,000 on tires] and i am astonished at the rate of wear.

but more importantly, i find the tires totally lacking in wet road capabilities. and though metro-houston has been in something akin to a drought, when it does rain, these tires are not suitable.

porsche, as did m-b for the c215, fits a dry weather tire. and porsche goes further in recommending only a porsche-sanctioned version of a few dry weather tire. PORSCHE RECOMMENDS NO ALL-WEATHER TIRES for this vehicle. and prefers some porsche-specific version tires for the summer tires that are also available without the porsche specific designation.

personally, for driving in the texas gulf coast, my criteria is for an all season tire[focusing on wet condition handling, braking].

porsche sanctions no tires of these specifications. but i am looking at the yokohama parada spec-x and the continental extreme contact dws when i replace the bridgestone dueller h/p sport tires within the next 2,000 miles.

what would be your thoughts?

Albert, while I have no experience with Porsche automobiles I suspect the recommended tires are Z-rated (with a low Treadwear number on the sidewall). The soft rubber compound provides superior traction in dry conditions, but wears quickly and can handle sustained high speeds.

All the tires Porsche recommends likely are Z-rated with a stiff sidewall. The sidewall on all-weather tires is not as stiff so Porsche realizes handling will suffer, and doesn't recommend them.

What type tires you install is your choice to some extent. I know that some tire dealers will install only tires that their computer system shows as compatible for a particular automobile. If you take loose wheels to have your preferred tires installed that would be a different story.

When I replace tires on our MB automobiles I take loose wheels and new tires to our local MB dealer because they use the 2-piece MB balance weights. That way I avoid wheel damage and cheap lead balance weights.

__________________
Fred Hoelzle

Will you take the Porsche to it's top speed? Not likely. Therefore, go with an all-season tire of your choice and worry less about about sliding off the road on a wet day. Can I drive the Cayenne? lol

__________________
John Breslin
93 500E, 92 500E, 86 190E 16V, 62 220SEb
Music City Chapter MBCA

Better pull out that too-powerful engine, too.

__________________
Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

thnx yr responses.

no, i am not going to be running this beast beyond 100mph.

in this almost drought year in metro houston, tx the factory fitted bridgestone dueller h/p sports have been fine. but when i am driving it when it is raining, those shoes are spooky.

i encounter similar spookiness with shoes for my m-b 2006 cl500. once again, m-b fitted as oe summer[dry] condition rubber.

15,000 miles ago, i fitted the newly introduced continental extreme contact dws shoes.

initially not bad in the wet. but as the rear shoes wore at twice the rate of the fronts, in the last 2,000 miles, once again the car became spooky in the wet.

new safety inspection time for the cl500. new shoes for the rear. those contis were down to the wear bars.

fronts were only half as eroded.

for the other benzes that i drive regularly, i have found yokos to be the best. the avid v4s on the 1997 s500c and the avid h4s on the e320 cab. quiet. excellent in the wet, transmitting road feel.

i think the 1987 560sec is running another yoko bit of rubber. much quieter than the oe michelins. and far superior in the wet.

the most astounding shoes that i ever ran were the michelin xwx's that i fitted to my 1986 560sel. no durability, however.

May be apples and oranges, but...I had a friend in San Antonio who complained that her tires had plenty of tread but she constantly skidded on wet pavement. Thinking it was her brakes, she had already had much brake work done with no help. When i flew down to see her, i found that there was indeed plenty of tread, but the compound was rock hard--no grip at all when wet. My (unscientific, uninformed, ametuer) theory was that the summer heat cycles had cured the rubber. Made for no tread wear, but also no wet grip.

If there is any credence to that, then another consideration might be getting a sense of whose tire might be less likely to harden with repeated high heat cycles. Just a thought.

__________________
Earl McLain
'02 C230 Kompressor
'89 560 SEL "Frau BlueCar" (retired April 2004)

shoes for high-performance vehicles remain a mystery to me.

on the other hand, i have found the tire rack survey results to be pretty much spot on.

and because i consider shoes the cheapest method of achieving active safety, i try to run the best in certain categories of performance: wet handling, wet braking, quietness.

had i not been planning a run last year into the high altitudes of the desert southwest, i don't think i would have acquired a porsche cayenne turbo. on the other hand, after acquiring a virtually unused,loaded 2008 model, i care to say this - porsche did it the best of any similarly styled vehicles. it puts all the similarly market-targeted benz models to shame. renders them as soccermom conveyances.

what brought this up is that porsche has this thing about "its recommended tires". all of which are considered dry weather tread designs.

on the texas gulf coast, dry weather tread design and compounding don't satisfy me. in the wet, those specs can be quite scary.

benz is just as crazed as porsche by the way. it also prefers to fit and recommend dry weather shoes.

i run 'em until replacement is indicated, then i fit all weather shoes, that lead the tire rack evaluations for wet performance and quietness.

the cayenne turbo is a fun horse to ride. the fit and finish are superb. and being seated high so as to look down the interstate is a real plus.

the astonishing aspect of the vehicle is the implementation of torque and horsepower at already elevated speeds, allowing you to move through slow moving clots of interstate traffic as if those clots are parked.

ordinarily, i would never acquired such a vehicle. almost a year later, i am tickled that i did.