I put new 195/60x15 tires on 5 1/2" Fuchs to replace the original Michelin 165 x15's.
Do I run the same tire preessure as before; 30lbs rear and 27lbs front? I have this amount of air in the tires now but they look "flat". Since the tire size has increased, does the amount air have to increase too??? What inflation pressure do most of you use?
Thanks for the help.

The pressure is not directly the amount of air,
wich means to get the same pressure in a bigger tire you need more air....

I run 34 all the way around on 205's which gave me a great feeling and traction on the road.

'74 2.7L /6 conversion - 5 lug

I run 15 X 7 Cookie Cutters with approximately the same size tire (185/60)

I also have a set of 15 X 6 Fuchs with 195/60 that I have had on the car (not excited about Fuchs and one tire requires to much weight to balance it for my comfort).

I run 26 front and 28 rear just like the factory specs. Pressure run is a function of the weight of the car and heat buildup to maintain maximum tire contact patch with the road. Last thing you want is to have to high of pressure to crown the tread.

When I ran the Streets of Willow with the car, I reduced the pressure to 25 on all corners.

When we raced on Goodyear slicks and using a tire pyrometer to check temperatures to maintain full contact, initial pressure was set at 19 lbs on all corners (2100 lb car, 50/50 weight distribution).

Play around and set them for your type of driving and comfort, but I feel starting with the factory specifications is a good place.

Unfortunately, every tire and wheel combination is slightly different. Starting at 27/30 is probably a good idea and a good baseline. Ultimately where they belong is determined by tire wear ( bald in the center, pressure too high ) ,ride quality ( are you getting beat to death ( too much pressure ) ? and does the car handle the way you want it to ( turns in to corners well etc. ) . Going up or down 2 psi can make a big difference to a sensitive driver who knows his car. Too much pressure...near the max inflation pressure marked on the tire, will give you a harsh ride, poor handling and wear in the center of the tire, but isn't dangerous. Too little pressure ( below 20 psi ) can cause excessive heat in the tire and lead to catastrophic failure. 27/30 sounds good to me .

I run 35psi of Nitrogen... Not air...

You have to find the sweet spot for your tire combo and driving style.

I run 205/50/16 on 6" rims and use the stock pressures. Tread wear across the tires is excellent.

Yokohama S Drive P205-50-15 street not track running 27LBS all four corners, don't put enough miles on it to know how the ware is but the ride is much better then 30 plus lbs. Cars relatively light so lower pressure may be relative, i.e. my truck runs 35 LBS.