About 10 months ago, I noticed a fairly precipitous drop in gas mileage in my 2001 6-cylinder Automatic Rodeo, from the 18-20 mpg range down to about 11-12 today. I'm not 100% sure if this was an overnight thing, or something that happened over time (my wife is the primary driver of the vehicle). I've taken it to 2 mechanics, both of whom don't know the cause. Several people have mentioned the increased use of ethanol in gas today. I use Regular Gasoline all the time (87 octane). Couple of things I've tried:
- Only put 10 gallons of gas instead of a full tank - no effect.
- Run the car without A/C (1 mechanic thought it may be some kind of drag the A/C system was putting on the engine(???) - no effect.
- 1 tank of 93 octane gas - no effect.
I did notice that the car goes about .95 miles for every mile the odometer reads...so, that would do some damage to my perceived gas mileage, but it doesn't account for the roughly 40% drop I've noticed.
Has anyone else had this problem? Any ideas? Fuel additives, or more regular usage of higher octane gas?
Thanks!