Hello
I inherited a Volvo S40 2001 with 50,000 miles on it (I don't think it has turbo). The first thing I did when I got the car was bring it to the volvo dealership for an inspection, which it passed with no found problems (I had thought maybe the coolant boiling out when i opened the radiator cap was a problem, but apparently not.) now that I have it back, I just realized that the gas mileage is terrible - around 5 mpg or less in the city!
does anyone know what the problem might be? the air filter looks clean and the tiers are at the correct pressure. I heard that perhaps it could be the spark plugs or O2 sensors, but the check engine light is not on, and could these factors alone account for such a dramatic reduction in MPG?

Thank you for any insights.

 

All North American market 2000-2004 Volvo S40's had a 1.9L turbo engine. The European versions had other options like a 1.8L and even a diesel engine. Are you in North America?

5 mpg? Ouch. A bad top O2 sensor will lower your mileage but not that bad. I'm thinking you have a stuck caliper or collapsed brake hose or partially applied parking brake. Try driving the car around the block to warm it up then stopping and checking how hot the wheels are. This happened to me just last week in my new-to-me 1995 Chevy truck. The right front brake hose collapsed internally and caused the right front caliper to not release pressure. The result was a very hot wheel in a short time. So hot it burned my fingers touching the wheel.

 

Thank you Hudini! hopefully its just the breaks, but I just had them replaced at Volvo (cost was high so the job should have been done right - or at least one would hope).