senicalj4579

iTrader: (41)

Had my mt dr 275 40 17 for about 10k miles. Kept them at 32psi for street use. The centers are worn much more than the sides. This is my first set of these tires. Before you tell me they had to much air 75-100% of max psi is recommended by MT for street use. 44 psi is max on these tires so that means 33psi for street use. I guess these are truly a track tire meant to be ran with 20psi or less huh?

senicalj4579

iTrader: (41)

http://www.mickeythompsontires.com/tech.php?bulletin=s3

oldguy99Z

iTrader: (2)

I think you are running more psi than most people probably run in those.How wide your rims are would also affect your tread wear.I can tell you that I have some MT 275/40/17 dr's also on 9" wide 10 spokes and run 27-28 psi on the street and they bow out in the center a little.Actually I think you did pretty good if you have 10,000 miles on those tires and they are not worn out.I would be happy with that-those tires aren't designed for good wear you know.

FASTFATBOY

iTrader: (23)

Center wear is a sign of too much air.

senicalj4579

iTrader: (41)

I just checked my service notes and I had these tires a little over 12k. Maybe 15 track passes also. To tell you the truth, I never took any air out at the track because I was hooking at 32psi launching the car just off idle maybe 1k. They are bellow the wear bars now. Another thing is I didnt really punish them on the street but one time when I laid a 30' strip up hill LOL


yep

RevGTO

iTrader: (12)

I run 18-22 track and 25-27 street. I've never heard of anybody running over 30lbs. on the street. These tires tend to wear from the center out in my experience. Running 32lbs. is just going to make it worse.

senicalj4579

iTrader: (41)

Yea I hear ya. MT must recommend 75-100% of max psi for street use for a reason though.

StraightTimeStirrups

For Lawsuits so you dont blow a tire off the bead from cornering too hard!

You should chalk line every tire on every car with the tires up to operating temp and drive it down a dead level road (no Crown in the road) and start at max pressure drive a couple of hundred yards and see where the chalk is worn. If its worn in the middle and not the sides, the tire has too much pressure for the load on it. Drop the pressure until the chalk line has worn evenly across the tire.

Once you have done that, you will have inflated the tires to the proper pressure required for the load it is carrying. Up or down for that you need to experiment for your best racing results for the conditions on the track!

Joe

blue98Z

iTrader: (29)

Well said Joe!

ABA383

iTrader: (1)

That's how I've done it for years. It's the only way to accurately check proper tire inflation on the street.

--Alan

FASTFATBOY

iTrader: (23)

Or just do a tire cleanoff on a good road to see the black marks. Stripes on the outside, blank in the middle means not enough air.

Black strip in the middle with no outer marks, too much air, adjust to get a full black mark on the ground that matches the width of your tire.

underpressureWs6

iTrader: (17)

ive ran the 295/45-17 mt dr's for 4 years now and have gone through 2 sets, i keep them at 28psi on the street and they wear very even all the way across the tire.

11SECSS

iTrader: (199)

with my car being lighter then most I run 25psi on street and 18-20 at track.

lemons12

iTrader: (71)

You're too smart for your own good! LOL

Quit doing math, we're gear heads... 25# is the most I ever ran.

senicalj4579

iTrader: (41)

lol since this thread I dropped them down to 25psi cold. The car feels more boaty around corners now though and not so sure I like it on the highway.