[88 coupe]

Originally Posted by Oldsguy

I heard ........

Is it reasonable to assume the author’s statement was not challenged, at that time?

........ it would be more accurate to turn the driveshaft ........

You have a shaft, with a hand crank on each end. Using one crank, you rotate that shaft, exactly ten revs, and then another ten, using then other crank. Which crank gave you the most accurate reading?

Now let’s split the shaft in two, and add a couple of reduction gears, between them. Now we repeat the same tests using the same cranks. Which crank gave the most accurate reading.

Now put a crank on the subject driveshaft and then one, or both, wheels. Which crank would show the most accurate reading.

I heard it would be more accurate to turn the driveshaft and count the revolutions on one of the wheels (they should both be up in the air) ……..

I would have asked the author to explain his logic.

…….. This is because the driveshaft is the source of the power to the wheels anyway so you are applying power and "simulating" the same action of the car in use.

OK. The author drove his car for exactly ten miles, then got behind and pushed it for the same distance. All the time, keeping count of all driveshaft and wheel revolutions.

Assuming no tire slippage, what difference, in numbers could we expect between the first and last ten miles of the trip?

Did the numbers change because the wheels were turned, instead of the driveshaft, during the second ten miles?

Norm