[s-cars] BR improvement over G60's; correction

[Steve Marinello]

Actually, as Richard and I suddenly realized, while the effective diameter
increases by 26% with the Big Reds, since area is the issue here, it is
related in terms of the diameter squared, so the actual cross sectional area
improvement going from the G60's to the Big Reds is just under 60%.

The improvement has to be based on the absolute difference in cross
sectional area.

Factoring out the pi/4, you have  [2(44x44)+2(36x36)]/2(45x45) = 1.596

You don't take the square root; that's just to get at the equivalent
diameters.  Actual difference in area is in L-squared dimensions; the cross
sectional area, as stated above.

It's been almost nine years since I left academia...pretty bad for a former
engineering prof......

Steve