I am going to look at a 1990 740 turbo wagon later today and would appreciate some advice. I am very familiar with NA 240s and have checked the 700 FAQ. The car is supposedly "fully loaded" and well maintained with 190,000 km on it. Asking price is $Cdn 6900. I have no experience with turbos and am worried they will be a maintenance issue - upkeep costs are a big issue for me, but I do intend to do all my own mechanical repairs as I have done on my 83 DL wagon for the past 5 years. The questions:

How reliable are the turbos? I think this one will have the series 3 Garrett.

How does the AW71 compare to the rock solid M46?

The check engine light is apparently "on" in this car and the owner wants to sell without a safety - is this most likely a service reminder light, as the car has apparently been very well maintained?

Any easy checks for a worn out turbo?

The engine specs for a 1990 B230FT list the compression ratio as 8.7:1 - does this mean the engine can be run effectively with little or no boost?

Do I have to run premium gas in this engine? What kind of gas mileage can a conservative driver expect?

Many thanks in advance!

Ron Lynes
83 DL wagon 300 K km
near Brantford, Ont, Can