The gas mileage in my car is degraded significantly the last three tanks. What should I look for? Details of the vehicle are below, but this question could also apply to anyone who sees this problem with their car.
It's a 2005 Chevy Aveo, about 108,000 miles. I normally get about 32 (which already seemed low for a compact), but recently I'm only getting 23-24, or a 25-30% drop. It's a manual (5-speed) transmission. I'm used to a small drop in mileage as the weather turns colder each year, but even then I still normally make at least 29-30. One other possibly-important detail is that we did store the car for about 6 months last year, but it had been doing well for a few months since we started driving it again (after some post-storage maintenance, of course). It feels like it still has just as much power as it always had, but that is an entirely subjective (unmeasured) observation.