Until now we were consistently getting 22-23mpg on the freeway from our '88 245 auto. The car also didn't want to go up the hills happily without taking it out of the overdrive. I changed a few things:

- a new OEM air filter
- air'd up the tires from 30psi to 35psi
- removed the clutch fan in favor of an electrical fan from an old chebby
- switched to "Energy Conserving" 10w-30w oil, whatever brand is on sale, usually $1.19 a qt.
- and this one i think is really what made the difference...there's a beige plastic vacuum hose that connects the intake manifold to the ignition unit (i think that's what it is, next to the windshield washer bottle), this was disconnected near the manifold so I reconnected it.

The car can now maintain its speed going up the avg grades and the gas mileage has picked up quite a bit.

218k and counting...