Lee the diameter is the deciding facter for your purposes.Bob G.On Thursday, November 17, 2005, at 09:36 PM, GT350HZ@aol.com wrote: > First for those who may not understand, I am trying to figure out what > is the best solution for a spare tire for a 1969 GT350 that is used as > a daily driver. Currently my solution is a can of fix-a-flat and a > cell phone. > I guess I am slightly confused about the whole tire situation of what > will fit in the trunk. If a standard tire and 15" Shelby wheel would > be a problem, then do I need a thinner rim and tire, or just something > smaller in diameter? The offset will need to be similar to the Shelby > wheel so that there is not problem in clearing calipers. I thought the > diameter of the tire wheel + aspect ratio of the tire should be the > same as the tires on the car to prevent any problems with the rear end > (in case it is used in place of a rear tire). The width of the tire was > narrower on an E 70 (185-195mm) than an F 70 (205mm) series. So if an > E series would fit, then the width of the tire is the difference from > what I know about tires. I measured a 60 series tire on a 15" rim is > about 25" in height. > My 17" wheels with 40 series tires (on my cobra) is about the same > height as the 15" with 60 series tires. I really don't want to have to > mount tires on a wheel to see if they will fit. Suggestions? > Am I just making this difficult or is the situation just messed up? > > Lee > 66 # 869 > 69 # 2055