i have a 99 v6 accord and i get horrible gas milage. like almost 17city and like 19 hwy miles a gallon. i change my oil every 3 months.. but i still cant figure out why its so bad. i dont drive like a racer. i let my rpms shift below 3 and i accerlate really slowly. i get the lowest gas 87 octante. and.. yeah? any ideas?

 

-Maybe some sensor is bad. The oxygen sensor is known to go bad, but not be bad enough to trip your Check Engine light. You could try changing it. http://www.oxygensensor.com . I think the Denso one is the OEM.

-You could also try changing the spark plugs. I know on alot of V6s the spark plugs are harder to change, so alot of people don't change them.

-Check your air filter and see if it is dirty.

-Do a compression test to see if your cylinders are all in top shape and not more than 10% difference between the cylinders

-Change the PVC valve. I changed it on my fiance's car and got a noticeable improvement in fuel economy ~$3-4

- clean the EGR ports. They are known to have buildups of carbon deposit which can rob the fuel economy.

-make sure your tires are properly inflated

-remove unnecessary items from your car which makes it heavier.