I have a 71 coupe RS replica with the following wheel-tire combination:
front: BF Goodrich Euro TA 225-50-15 on 15" Fuchs
rear: BF Goodrich Euro TA 245-50-15 on 15" Fuchs that look an inch wider than the front wheels

I just bought the car. The tires were brand new at the time of purchase.

How do I choose pressures when I have no treadwear to examine? Do I just start at the factory pressures?

 

yes, probably something like frt: 29, rear: 36..., maybe lower, with less difference between them, but confirm for your specific car. tire pressures are based, more than anything, on vehicle weight.

 

Thanks, Kevin!
I would have guessed only ~3lbs difference front to rear...

 

your guess may be right! check out the original factory recommendations for your car - that's the best place to start on tuning tire pressures.

 

Thanks, Kevin- the factory are 33 front / 36 rear so I'll just start there...
I appreciate your help on this!

 

On the later cars with 16" rims the pressures were 28/29 (205/55 x 16)up front and 36 rear (225/50 x 16). If you like to run alittle loose (like me) then the pressures can be slightly higher, 30 psi up front and 39 psi rear (because I'm measuring the pressure on a warm tire (I have a short drive to get to the air pump), I'm really at the equivalent of 28/36.

Richard
'87 Carrera 3.6L <img src="graemlins/yltype.gif" border="0" alt="[typing]" />