I just bought a 95' GMC Sonoma bone stock with 98,000 miles. I haven't driven it long enough to find out but, What kind of MPG should I be expecting on the highway? And what's the best quickest way to get the most MPG? Other than driving it right.

 

I had a '95 with the Vortec 4.3. It would get between 24-26 MPG on the hiway w/o
babying it. But I had a few tricks that I'd hoped would really work on city streets, but
they worked better on the open road. Instead of 32 psi in the tires, run between 35-38 psi. Make sure all the filters are clean. Regular oil changes with 5W-30. Keep it tuned, use platinum plugs, but plugs are a pain to change - go thru the fender wells.

Taller tires help, narrower tread works too. Anything to lessen rolling resistance will
help. Ride the hills with foot off the pedal, but this requires a change in driving habit.
There have got to be other tricks, but I hadn't found them. Who knows maybe some
other aftermarket stuff will work as well. Forget the flex fan, they don't make 'em to
fit the S-10 Blazers. You would have to go to an electric fan to reduce demand on the
engine. In the city, you'll get around 16-18 MPG - maybe.

I used to load mine down with all kinds of stuff and of course the more weight, the
less the MPGs.