This past weekend we took a trip from Charlotte to Atlanta. My Prius is a 2004 with 108,000 miles on it. I normally get 47 mpg but on this trip I averaged 39-40 mpg. Since its fall and the A/C is running I should have got slightly better than average mpg. My tires or tire psi haven't changed. What could cause this drop in average? I have looked through the schedule maintenance book and there is no major service until 150,000 mi which is spark plugs and coolant. So what gives?
I remember the spark plugs and coolant are actually at 110-120k miles. Have you changed the engine air filter at 90k?
Maybe your state has switched over to Ethanol gasoline which contain 10% ethanol. This will decrease your MPG up to 10%. alfon
AGH! That's my problem. I can barely get it up to 47, and still trying for 48 on this tank. I'll start using 'better' gas (Exxon, Shell, Chevron, ect.) and see what happens. I talked to a mechanic at the dealership and he told me about the ethanol. Is there anything that can make the mileage get back up to 48-50+?? Going to make sure the air filter is always clean too.
