C5 - Tire Pressure in Non-Run Flats

Yokohama AVS's @ 35psi front and rear--same as on the C4. Haven't got enuf miles to get a measurement of wear across the tread yet. Feel good.

-- PJ '89 Hookercar '02 e-blu coupe

You won't get the tire builder or the dealer to give you an answer on that one. Best to look at a car that uses the tire brand you pick and see what they are supposed to use. Another way is to set it on a very smooth surface and blow it up until you see the edges lift. Then back it off so you have a flat tire patch on the road which should be about 10% more than the run flats as a maximum. I've run anywhere form 31 to 33, even tried 35 but it's to harsh and won't stick in straight line acceleration. At the present time I'm running 31 cold which will build to about 33 hot.

RUN FLATS SUCK!!!! If you run what they tell you, pressure and alignment, the back wear out in the middle and the front wears out on the inside edge, cups. Four set all did the same thing, first set I had 4 wheel alignments twice before I took them off and threw them away. Second set was the same thing with one alignment at 4,000, replaced them with none run flats. Third set was the same thing on the '04 with one alignment at 8,000 I put on the first set of none run flats I kept from the first C5. Fourth set was the same thing with one alignment at 8,000, couldn't stand them at 15,000 and replaced them with none run flats.

I'm only on about 2,000 on the '06 with none run flats and it's like getting a new car.

Dad

Dad, how many miles were on your c-5? I have over 80k, 4 or 5 sets of the fact runflats. I had no prob with them , except they don't last long. I get even wear , and have never had an alignment. Diit with my neighbor, who has over 100k on his 00 C5. the stock goodyears have a higher speed rating than the competition as well. What I do like about the runflat is besides being a good perfomance tire, is its inherent safety feature. And the money you save on buying non runflats may be spent on rim repair when you get a flat. I

Right at 70,000 but 20k of that was with non runflats. The reason for the alignment was because they cupped in the inside front at about 7,000, all 4 sets, which includes this C6. I have no rough roads, no curbs to bump and park in a garage and the alignment showed no need to change its settings.

By the way, there was no cupping on the non runflats on any of the C5s with

3 times the miles on them. My driving tends to be long sustained drives at speed, not short trips. My effort is not to save money but to have a safe tire that will allow me to have a conversation without the tires singing so loud it's impossible. I do my short trips and shows, (if I do any shows) in my ''72, my feelings since 1957 have always been that to enjoy a Corvette you drive it, not show it off.

When was the last time you saw a 35 series tire let the rim hit the road? One of the first things I did in '97 was to take the valve core out of one and drive the runflat to see what it would handle like. Being curious I did the same thing with the non runflats and yes they let you down some but they are controllable. You hear the runflat and you feel the non runflat, but you would have had the low tire pressure warning long before a leak would have you in trouble. Now a blow out or a severely ruptured tire is a whole new ball game with either tire.

My theory is that the runflats are not made for sustained speed driving. The heavy edge blocks get to hot and start to sling out causing edge wear, cupping. My last set went to GM mounted on the rims after they were replaced, rim, sensors, and mounted. They checked them at 1,400 and 8,000 miles and they still cupped. That was just a couple of weeks ago and I've heard nothing yet, will be happy to just get my wheels back, they can have the tires.

As a note my third set of runflats had 7,500 miles on them two weeks after I took delivery of the '04, they were replaced with non runflats that week. If they would have fit the C6 they would be on there today.

One thing I'll say for the car and the tire is that they are strong. Going through the Rockies in heavy traffic I nailed a rock about the size of a softball at speed and it sounded like it tore the right wheel and front end off. Brought up the tire pressure and watched it until I could get to a turn off and there was no pressure lost. Other then a scratch on the bumper cover and a cut in the air dam there was no visible damage. Later that day I found an alignment shop in Buffalo and had them check it, everything OK.

Drive what you're happy with, me, I'm not happy with the runflats.

Dad

Thanks...appreciate the advise.

Mike