Ok so i jsut took my 91 740 turbo on a 100 mile trip each way.....it ran fine at about 3000 rpm at 70mph....but i seemed to run through gas......i got really bad gas mialage....any answers?

 

The usuals would be plugs, cap, rotor, wires, fuel filter, air filter, etc. These things are all common culprits to bad gas mileage. What kind of mileage were you getting?

 

I agree!!

 

FYI the mileage on that vintage of Volvo isn't all that high, my normally aspirated 940 got 20/25 on the EPA tests. The turbos were one or two MPG less (thinking 19 city). Look it up on the US gov website if you want to know exactly.

I increased the mileage on my n/a 940 by 10% (that's TWO MPG) with new plugs and eliminating vacuum leaks (the vacuum hose ends were all loose). Also the cars will get less MPG with regular fuel (there is a knock sensor to prevent detonation, but using regular cuts gas mileage a lot). It's up to you whether the current 18% price difference in fuel for reg VS premium is worth it.


Even before those repairs, I got 25 MPG on the highway.

 

Strangely enough, I was poking around my engine bay and I found a few disconnected vacuum lines. LOL. I just replaced the lines, and I've actually seen a significant improvement in my gas mileage. Good call carbuff.

 

I use regular in my 940 and get consistantly 24 MPG. But the previous owner ran premium from day one. I may go back to premium. when you look at a different way it's only $4.00 for a tankful and around here they don't sell much premium so it's only about 12 cents more per gallon.