Apparently yes, but keep up on the routine maintenance to be sure your car is running in the best condition at all times. Like was mentioned before, a bad alternator can produce more drag on the engine, and lower power output which translates into lower voltage at the spark plugs meaning inefficient combustion and less power produced by the engine. All this can suck up some fuel.ammorgan said:But wouldn't the alternator stopping charging kill the battery?
Our alternator just went out and we got it fixed. I was trying to figure out if maybe that is the reason why our mileage had gone downhill over the past few months.