275/40ZR20 Conti's feel a bit rough/loud....Tire pressure?
07-28-2010, 01:47 PM
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275/40ZR20 Conti's feel a bit rough/loud....Tire pressure?
Switching from stock 18's to 20" Sport Technos with 275/40ZR20 Conti DWS, the ride is noticeably rougher and louder over my old Conti Sport 4x4s. Discount Tire inflated the fronts to 41PSI and rears to 50PSI cold. Is that a bit high? When I purchased the car on July 10th, 2010....Porsche of North Scottsdale had the tires inflated to 39PSI for fronts and 41PSI for rears. I'm thinking about deflating the rears down to 46PSI or so....Any thoughts?
07-28-2010, 05:55 PM
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No. This is a function of the tire size. If it is a big issue, go back to 18s.
I wouldn't trust Discount Tire before a Porsche dealer for proper inflation guidelines. See if Tire Rack or Conti lists it on a website. No matter what you have for pressure on larger wheels, it will be louder and rougher. I would want to make sure I have the best handling instead of a softer ride. I doubt you will find anyone that advocates under-inflating your tires.
PS - I think you meant Porsche of NS had the rears at 51 psi, not 41?
I wouldn't trust Discount Tire before a Porsche dealer for proper inflation guidelines. See if Tire Rack or Conti lists it on a website. No matter what you have for pressure on larger wheels, it will be louder and rougher. I would want to make sure I have the best handling instead of a softer ride. I doubt you will find anyone that advocates under-inflating your tires.
PS - I think you meant Porsche of NS had the rears at 51 psi, not 41?
07-28-2010, 05:59 PM
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Look at the sticker inside the door - it should tell you the proper pressures for 20" wheels/tires. I'd look at mine, but I'm in Hawaii right now and my Cayenne is in Colorado.
07-28-2010, 06:13 PM
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No. This is a function of the tire size. If it is a big issue, go back to 18s.
I wouldn't trust Discount Tire before a Porsche dealer for proper inflation guidelines. See if Tire Rack or Conti lists it on a website. No matter what you have for pressure on larger wheels, it will be louder and rougher. I would want to make sure I have the best handling instead of a softer ride. I doubt you will find anyone that advocates under-inflating your tires.
PS - I think you meant Porsche of NS had the rears at 51 psi, not 41?
I wouldn't trust Discount Tire before a Porsche dealer for proper inflation guidelines. See if Tire Rack or Conti lists it on a website. No matter what you have for pressure on larger wheels, it will be louder and rougher. I would want to make sure I have the best handling instead of a softer ride. I doubt you will find anyone that advocates under-inflating your tires.
PS - I think you meant Porsche of NS had the rears at 51 psi, not 41?
The car had been on the lot for over 100 days before I purchased it....I didn't realize the pressure was low until the day before my 3000 mile cross country trip....@Dennis: Will check when I leave work today. Think it'll list the 20" tire pressure even though my CS came with 18's from the factory?
