Truck was tuned to the old, nearly dead spark plugs, so the computer had overcompensated for a long time. Therefore, the mix was lean and tight, and the first road day after the tuneup, I got 27 miles per gallon.

Now, it’s not good for a vehicle to run that lean (and hence hot) but it was amusing how much you can squeeze out of an 8. And I pushed the bugger, too. Back to the usual 17-18 today.