14.5 x 32 good years on 2 cars. 6.5 in my 2650 pound truck and 6.75 pounds in my dads 3150 pound Nova... Only 5 in my 16 x 33's on my dragster... Hope this Helps!
In my experience 9.5 would be way too much. The thing to remember is that every guage is different and you should use the same guage everytime. I have 3 of the Moroso guages that are all the same part number, but all read a little different.