I've owned several older (80 -90s) Volvos. Loved em. Expensive to fix, parts are hard to come by but comfortable and easy on gas. Except the automatics, they lose about 20% gas milage compared to a 5 speed standard tranny.
The last one was an '89 740 Turbo manual 4 with od, consistently got 35 mpg unless I was playing around. At 200 kph you could watch the fuel gauge dropping.
I bought them cheap with high mileage and drove em till they started costing me money, usually around the 400,000 - 500,000 kilometer range.