Hi,
The gas mileage on my 89 240 wagon is OK for a Volvo but I would like to do better. For the size of the engine and the weight of the car the acceleration is quite good. I would be happy to give up some of that acceleration for better gas mileage.
I am wondering if there is some switch somewhere in the electronics or the fuel management systemthat lets me choose between power or economy? Anybody know anything about that?

 

The only change that would be a direct correlation between your fuel economy and pickup at the stock level would be to change out the rear diff. I'm assuming that yours is running a 3.73 gear and I'm pretty sure my 92 740 wagon is as well. Other than that you can do the basic fuel economy mods (plugs, wires, etc) to help gain mpgs. I see about 27mpg if I'm easy on it and don't go over 65mph on the way home.

 

if its an automatic, im sorry. but on to the point at hand, do the basics, tune up incluiding fuel filter. then run a bottle of Red Line fuel injector cleaner when you fill up. make sure you have no exhaust leaks, make sure your PCV system is clear and working good. try using some MAF cleaner on your MAF meter and have a good clean air filter. if your really looking for some adventure, you can take the intake manifold off and really clean all the oily crap out, same with the throttle body, but if you do this make sure you get a new throttle body gastket and a intake manifold gasket....other than that, i would say drive it normaly, and you should get a little better after a full tune up and make sure your running good fuel, not arco crap. just for a base line, my 87 244 gets about 37mpg hwy 32 city and it just turned 280k miles. hope eveything works out for you!!