By changing to a smaller diameter tire you are doing the equivalent of
numerically raising the ratio in your rear end. It will now require a higher
RPM than before to maintain the same speed.
>===== Original Message From Dave Houser <mgs4dave@warwick.net> =====
>Folks,
>Just purchased a set of 4 tires thru the Tire Rack, Pirelli P-400's
>175/70-14's to put on the NOS Minilites for the 64 B roadster. At
>present I have a set of Dunlop SPs of 165SR 14 size on the stock steel
>wheels.
>I wanted to make sure that there would not be any clearance problems,
>that's why I went for that size.
>Well, I mounted one tire on a Minilite, compared it to the height of the
>165SR 14 and there was at least a 3/4" difference(smaller) and put it on
>the rear. With the tire on the car and jack removed, I looked under and
>there is gobs of clearance from the wheel well outboard to the inner
>wheel well. So much for that concern. Now, here's the question: Since
>I'll have a smaller diameter wheel/tire combination, how many more revs
>will the engine have to turn at 60mph? I know I should gain in
>acceleration, but lose in making the engine work more at speed.
>Anybody help?
>Cheers, (Four days to Carlisle!)
>Dave Houser
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