I have a 87 Turbo wagon that gets 30 mpg plus at 65 miles per hour. Keeping the car is more of a benefit to the environment. The energy has already been spent to build it and ship it to your city. The spare parts are already have been made and sitting on a shelf in a warehouse here in the states. If you baby it you should see 22 to 24 mpg around town and over 30 on the highway. Right now you have a paid for car with low insurance premiums. Volvo's in general run very clean emissions.
Fill with a good synthetic motor oil and run it for 6k mile oil changes and swap out the differential fluid with synthetic. Being you already have a locking torque converter the benefits of going to a manual will be minimal in fuel mileage gains. With a non locking torque converter in the Turbos makes the swap to a manual well worth it.
As far as the transmission fluid being swapped out for synthetic it is going to be $120 just for the fluid. Synthetic fluid in the rear end will give you the best bang for the buck when winter comes.
Pump the tires up to 38 to 40 psi and make sure the alignment is dead on spec.
Keep the car under 65 mph or 2500 rpms when on the highway. With an automatic I have found the best speeds to run a Volvo 700/900 is between 60and 65 mph for the best gas mileage. Once you go over 2500 rpms your fuel mileage goes into the toilet.
If your into spending money you can call up IPD and get a set of lowering springs. Then for a few bucks for materials close up the area between the differential and the rear bumper. The rear bumpers on these cars act like a
parachute at speed. Both tjts1 and I have seen a 1-2 mpg increase just with this one modification.
Pics of the mod under my 97 960.
