tochatihu said:
Perhaps he knew the screen miles and mpg, both before and after the service, and without resetting. Did some math. It would not have been completely out of line to report two significant figures, and even more amazing to onlookers.
Extra points if a calculating device was not utilized.
DAS
DING DING DING! You win the prize.
Take miles/MPG upon bringing in the vehicle. This is the number of gallons used before taking it in for service.
Repeat for miles/MPG after the service. Subtract 2 from 1, that's the gallons the service dept used.
I don't recall the actual numbers any longer. I think they drove it 2 miles though. And yes, I did use a calculator, but that was it.
Now that I think about it, it may have been closer to .057 gallons. I vaugly remember calculating the MPG for the service, and came up with 35MPG.