Tire SO3

[Mrdi]

My search netted advice on racing so....
Suggested street tire pressure for
SO3 245x45x16 and
So3 225X55X16
Tire mounter suggested F38/R48 seems Hi.
Break in suggestions?
All Comments appreciated.
Thanks,
Mrdi

[cstreit]

I run about 34/36 street in cooler months. 32/24 hot summer. Seems good.

[thabaer]

Pressure requirements can vary depending on WHAT 225 or 245 you have mounted. I found myself running 36/42 once to keep the rears from scrubbing away the center tread. Try to get actual S-03 info if you can, they've been out long enough now that there should be easy to find that experience on this board.

[Mrdi]

Just called tire rack. They say 29/36 ?

[racemor]

How does tire rack's recommendation compare to factory settings? I'm wondering because I'm using stock pressures on my '73 with 205-55 SO3, which are a very different size from the originals.

[NYSCAR]

Hey racemor,

I was thinking about the 205/55-15 SO3's for my 73 S, how do they fit on your car? you like 'em? How do they look (smaller?)?

Thanks

Brad

[Mrdi]

The 225 55 16's fit on the front of my 88 911, I've heard of others having problems but not with the 15" wheels

[Randy W]

I've had mine about a year - great tire. SO3 pressure are somewhat camber dependent - if you have 1/1.5 degrees negative, 32/35 on a 2400 lb car seems to work well. Less camber seem to need higher pressures. Break-in is not absolutely necessary, but best would be two medium speed laps followed by a hot lap then store tire/wheel off car for a few days.

[Mrdi]

I'm primarily
LOOking for street pressures not track

SO3's
F 245 45 16
R 225 55 16

Thanks

[racemor]

Brad, I love the tires! I've tried a good number of hi-perf street tires over the years on different cars. I think these may be the best I've had. Only a Hoosier or Kumho DOT race tire seems to have more ultimate grip. Seem to be as good in the wet as in the dry based on our local wet weather Pelican mountain drives. They are a little short but I am still running nearly stock ride height and alignment. I'll fix that with new torsion bars and shocks this summer I hope.

Here is a shot, mine is the silver car at the front of the row.

[Superman]

The greater the difference in pressures between front and rear, the greater the car's tendency to understeer. I use pressures a bit closer. Fronts are only 2-3 lbs less than rear.

Too little pressure causes tires to flex more, heat up more and wear faster, particularly in the tire's center where heat is greatest. Higher tire pressures do not sacrifice grip, they only run cooler and firmer, and wear longer.

[Mrdi]

So what numbers would you put with your comment
Superman?
F 36
R 40
?

[curtisaa]

your car appears to have 6's & 7's. What tyre sizes are you running ??

[Mrdi]

Fuch 7 225 55 16
Fuch 8 245 45 16

[racemor]

Curtis, they are 15" x 7" all around, 205/55-15 all around, rolled fenders. Only rubs in the really rough stuff pushing very hard. New alignment should help.

[NYSCAR]

Thanks for the info Tom, I think those will be the next tires on my 73 (not bad price on tirerack.com too!). BTW very nice looking E there

Brad

[curtisaa]

I am about to order thru Tire Rack 225 X 55 X 15's for the rear of my 70S. I have the deep 6's. I used to run these (225's) on my ex-73S but like you've done looks like I may have to roll the rear. We'll see..

[Randy Webb]

If I have 6" F and 7" rear wheels on my '73, is there a size of S)-3 that will fit? For sure? Or is it just an experiment to see if they fit w/o rubbing?

[RallyJon]

Better late than never... I just swapped the Euro T/A balloon tires out for S-03s in 205/55-15 front and 225/50-15 rear. The S-03 is a very wide tire. The fronts are actually 218mm wide on 7" wheels and the rears are 233 mm wide on 8" wheels. If they don't quite fit there are other tires in the same nominal size which are smaller.

Here are a few pics.