Why is my 1993 Nissan Sentra getting poor fuel economy?
My car has 123,000 miles on it. I have a 1.6L engine with a 4-speed automatic with overdrive. With the A/C off, it gets 24MPG; with the A/C on, it slumps down to 18-21MPG. I have replaced my air filter and spark plugs; my fuel filter appeared to be okay. My car is really slow. I have utility vans and buses pass me while I’m accelerating from a stop. It’s not so bad without the A/C, but even then the acceleration isn’t very good. My engine is supposedly rated for 110HP, but it isn’t putting out nearly as much; my girlfriend’s Ford Probe has 110HP and it out paces my car without even trying. If you floor it, it downshifts and revs really loud but still hardly goes anywhere. The engine sounds fine and doesn’t sputter or anything. My parents’ are getting 27MPG from their 2.4L ’96 Altima and 27MPG from their 2.0L ’90 Camry while I’m getting 18-21MPG from a 1.6L engine, the smallest of all of these. Here are some more details. For the person suggesting the thermostat is bad, my radiator has
