Hello in my 740 4 cylinder turbo I get very bad mpg. Recently I updated the air filter, spark plugs, fuel filter. And I still get bad mpg. Now when I had another 4 cylinder car with a bigger motor(2.5 iron duke), it got 25mpg. I dont know how much mpg im getting with the volvo since my speedometer doesnt work. But I can go through 4 gallons of gas after about 30miles or so. Maybe if I buy some new wheels the gas will improve?