Tire PSI, Dunlop SP5000?
10-12-2002, 07:01 PM
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Tire PSI, Dunlop SP5000?
I've been playing with my tires a little over the past few rides (the car's only been out 4 times) and I've come to the conclusion that I have no idea where the pressures should be... To many years riding motorcycles I suppose (but I can quote you those backwards and forwards).
Before I wait for the tread-wear to give me a clue, someone mind offering their thoughts? When I picked up the car from the PO, they were at 32f/30r - which seams a Lot low to me - as in, those were the pressures I ran on the racetrack with bikes. I have them at 36f/34r right now but have a sneaky thought that I should be even another couple PSI higher.
Anyway, anyone who's run these tires, your input is welcome. Shoot, even if you've got no experience with these tires, but want to offer general comments - that'd be appreciated.
TIA
Before I wait for the tread-wear to give me a clue, someone mind offering their thoughts? When I picked up the car from the PO, they were at 32f/30r - which seams a Lot low to me - as in, those were the pressures I ran on the racetrack with bikes. I have them at 36f/34r right now but have a sneaky thought that I should be even another couple PSI higher.
Anyway, anyone who's run these tires, your input is welcome. Shoot, even if you've got no experience with these tires, but want to offer general comments - that'd be appreciated.
TIA
10-13-2002, 02:33 AM
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Porsche recommended minimum cold tire pressure is 2.5bar(36psi) front and rear. Check on the back of the fuel filler door for the tire pressure sticker (or is it on the door jamb? - can't remember).
I have Dunlop SP Sport 5000's also, in sizes 225/50/WR16 front and 245/45/WR16 rear on stock Turbo S rims and run 37psi front and rear. These are an ultra high performance all season tire that I bought because of the higher treadwear rating of 340 and relativly low cost. I wouldn't recommend them for track use at drivers ed events, but for street use they are fine - very quiet, but not the greatest ultimate grip.
After about 15,000Km(9,320Miles), I had about 7.5/32nds of treadwear left - about 25% wear. The fronts showed very little wear - less than 10%. So I forecast getting maybe a little more than 50,000Km(31,000Miles) on the rears before the treadwear indicators show up. I was hoping for more than that...
I've also had sidewall punctures on the rears - twice! I've never had sidewall punctures before. So, is this just bad luck or are these tires susceptible to sidewall punctures - don't know?
Regards,
Jim
I have Dunlop SP Sport 5000's also, in sizes 225/50/WR16 front and 245/45/WR16 rear on stock Turbo S rims and run 37psi front and rear. These are an ultra high performance all season tire that I bought because of the higher treadwear rating of 340 and relativly low cost. I wouldn't recommend them for track use at drivers ed events, but for street use they are fine - very quiet, but not the greatest ultimate grip.
After about 15,000Km(9,320Miles), I had about 7.5/32nds of treadwear left - about 25% wear. The fronts showed very little wear - less than 10%. So I forecast getting maybe a little more than 50,000Km(31,000Miles) on the rears before the treadwear indicators show up. I was hoping for more than that...
I've also had sidewall punctures on the rears - twice! I've never had sidewall punctures before. So, is this just bad luck or are these tires susceptible to sidewall punctures - don't know?
Regards,
Jim
10-13-2002, 01:22 PM
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No. The tires maximum inflation pressure is listed on a tires sidewall. For these SP Sport 5000's the maximum is 51psi! I don't think you would ever want or need to run them with that much pressure.
Here is the definition of maximum inflation pressure from Tirerack's site on <a href="http://www.tirerack.com/tires/tiretech/tirespecskey.html" target="_blank">Tirespecs</a>:
"A tire's maximum inflation pressure is the highest "cold" inflation pressure that the tire is designed to contain. However the tire's maximum inflation pressure should only be used when called for on the vehicle's tire placard or in the vehicle's owners manual. It is also important to remember that the vehicle's recommended tire inflation pressure is always to be measured and set when the tire is "cold". Cold conditions are defined as early in the morning before the day's ambient temperature, sun's radiant heat or the heat generated while driving have caused the tire pressure to temporarily increase."
Here is the definition of maximum inflation pressure from Tirerack's site on <a href="http://www.tirerack.com/tires/tiretech/tirespecskey.html" target="_blank">Tirespecs</a>:
"A tire's maximum inflation pressure is the highest "cold" inflation pressure that the tire is designed to contain. However the tire's maximum inflation pressure should only be used when called for on the vehicle's tire placard or in the vehicle's owners manual. It is also important to remember that the vehicle's recommended tire inflation pressure is always to be measured and set when the tire is "cold". Cold conditions are defined as early in the morning before the day's ambient temperature, sun's radiant heat or the heat generated while driving have caused the tire pressure to temporarily increase."
