If you dont have the pumpkin open, you can spin a rear tire one revolution while counting the number of times the driveshaft spins (I put a piece of tape on the tire and a marker dab on the DS - both so I can keep track of revolutions).
If the DS spins ~3.5 times, you have 3.55's. If it spins just over 4 revolutions, you have 4.10's. Etc.
If you dont have the pumpkin open, you can spin a rear tire one revolution while counting the number of times the driveshaft spins (I put a piece of tape on the tire and a marker dab on the DS - both so I can keep track of revolutions).
If the DS spins ~3.5 times, you have 3.55's. If it spins just over 4 revolutions, you have 4.10's. Etc.
i'd suggest doing something like 10 spins, then dividing by 10 after. sometimes it can be hard to get a good reading, so this will reduce the error in your judgement.