Very low gas mileage, help!

[jchfriends]

Hi All:

I bought a used 2002 Avalon a month ago with 115K miles on it. I love everything about this car except for low mileage. I drive 95% city (frequent stop and go and mostly very short distance), and the mpg is only 14 with shell V-power premium gas. If I drive on highway, mpg could improve to around 20 for highway.

Other than this, I have not found anything unusual about this car.

Would a transmission or coolant flush help? I have to admit I do not know much about cars but I am trying to learn now.

I wonder if anyone has some suggestions, any information would be so appreciated.

Thank you.

[csaxon]

Do you know the cars maintenance history? You're in the tune-up mileage range (90-120k) when the spark plugs and timing belt need to be changed.

[jchfriends]

Thanks for your reply.

The problem is I do not have maintenance history of this car. The record of maintenance only shows one maintenance at 30K, nothing else. I doubt what the previous owner has done.

But I did a mechanical check when I bought it, I was told the dealer had just replaced the timing belt (with date on the belt). Hopefully I do not need to do it.

I am thinking to get the spark plug replaced, I heard it will improve MPG. But it also looks like a couple of hundred of bucks....

[csaxon]

If you can do it yourself the set of plugs is around $50. A lot of things influence gas mileage. Dirty air filter, fouled or weak spark plugs, tire pressure, dragging brakes, degraded 02 sensors (they start degrading around 90000 miles).
If the car was serviced by Toyota, they should be able to provide a computer printout. Good Luck.

[KoG506]

go to http://toyotaowners.com

sign up, its free, add your car vin # then go to service history

[jchfriends]

Thank you two.

I finally got a detailed report of my car. It is very helpful.

[MR2Jedi]

An ignition system tune up will be a big help. Plugs, wires and if your car uses them-cap and rotor. I would also check ignition timing. Proper tire inflation affects mileage too.

[maun]

Your car maybe running lean hence the high gasoline consumption. The leaness maybe caused by an air leak on the air intake hoses so you may want to check for cracks/leaks in the air intake hoses or any parts contributing air to the engine. You could also put an OBD II reader/analyzer on your car to determine the efficiency of the engine operation and then look for the problem being coded, if any. An auto supply store like Advance Auto has obd II loaners.

hope this helps,

Norman