[TR] Tire/Tube Q.

[Randall]

>    My point was about variation in grip between different 
> models within the same tire size.  Even a 165R15 is plenty 
> grippy for a street-driven TR4 (IMHO), as long as you choose 
> a tire with a good compound, like the Coopers... too bad they 
> aren't made any more.  Choose badly, and even a wide tire can 
> be downright dangerous.

Nick, I understand your point, and don't disagree (even through there is a
lot more to how a tire handles than just compound).  

My point is that all other things being equal, a low profile tire gives
better performance (with modern tire designs).  This means that the absolute
best performing tires are low profile tires.  Auto makers know this, and so
modern high performance cars take low profile tires.  High volume tire
makers get to be high volume tire makers by making tires that lots of people
will buy; not by making tires that very few people will buy.  Alas, high
performance tires that fit a stock TR2-4 rim fall into the latter category.

Just one example, the Porsche 911 was introduced in 1965 wearing 185/70
tires.  By 1970, it was wearing 195/60.  By 1980, it's descendent SC model
was wearing 215/60 in the rear (where most of the weight is).  1990 brought
225/50 and by 2000 they were up to 265/35 (!).

BTW, I was able to get 225/55-15 tires onto my TR3A; and they made an
amazing transformation in how well the car handled (along with a few other
modifications).  I was one of those guys that always thought the club runs
were boringly slow; while the guys on skinny tires had white knuckles and
complained about how fast we were going !

Randall