Spare tire diameter

[grubinski]

I would suspect the tire diameter is the same as the stock tires, so that the ABS doesn't get confused. On my S, which came with 17s, the stock tire sizes are almost exactly 25". If I don't see anybody else answer this, I'll pull mine out tonight and measure it.

I co-drove a Fiero rally car with a friend of mine (Doug Chase of Duvall, WA) about 10 years ago. I don't look down on them ... at least the engine is in the right place. More than you can say for a 911.