I purchased a 2000 Grand Caravan with the 3.3 flex fuel engine about 6 weeks ago. I previously owned a 1996 Grand Caravan with the 3.8. The 2000 has 54K miles. I noticed that the fuel mileage of the 3.3 was only averaging around 19 where the 3.8 was averaging around 22. I decided to change the plugs, air filter, pcv valve and fuel filter on the 3.3 to help the situation. Since that change 1 week ago, I have watched my mileage average decrease to 16. I gapped the (Champion) plugs at .050 like the book said, the air filter and pcv valve were both Fram brand and the fuel filter was a Purolator. Can anyone help determine why my mileage is getting worse? Thanks!

 

You could check for exhaust leaks. Make sure all your hose lines are not broken. Also tire pressure.

 

Sounds like you are looking in the right areas. A tuneup and properly inflated tires should have given you nearly a 10% increase. Pull the wheels - make sure you don't have a binding brake caliper or rear drum.

Also, you mention it is an E-85 capable FFV vehicle. If so, and youARE using E-85 you can expect aslight decrease in fuel economy (3-5 mpg hwy). This isa normal conditionwhile burning E-85 and MPG will increase when yourefuel withunleaded.

 

One thing you did wrong was to buy any Fram parts for anything.