Questions and Answers

Plymouth Voyager Needs Better MPG Q. Hello: We recently bought a 1998 Plymouth Grand Voyager with a 3.3 engine overdrive transmission and so forth. We really like the van because we were able to install a Braun companion seat in it for my wife's mother of 90 years. We average around 20 mile to the gallon and on a trip, no luggage, driving on the interstate in fairly flat country.

If I only drive 65 miles an hour we can get 23 miles per gallon tops. The problem I have is that we still have our old van 1989 Dodge Grand Caravan with a 3.0 liter motor and transmission out of a 1991 Dodge van. The reason being that the original motor gave out at 190,000 miles.

No overdrive and going on trips with all the luggage and a car carrier on top and driving 70 mph we can get up to 25 mile per gallon. I checked both speedometers out and they are correct and each vehicle has the proper size tires on them. The 1998 doesn't have any more pep then the old one, just drives nicer and quieter. Is this the nature of the beast?

My brother in law has a 2002 Dodge Caravan with a 3.3 liter with overdrive and he gets 26 plus miles to the gallon. Is there a difference in the motors or is there something I can do to improve my mileage?

A. My first thought is that I’d really want to know your mileage and when the last time the vehicle had the oxygen sensors replaced. Older, worn O2 sensors can degrade fuel mileage without setting any codes or causing the check engine light to come on.

If you don’t know this information, it would be best to plan to renew them as you would then establish a baseline for future maintenance. The sensors maybe a bit costly at first but you can perform a simple cost comparison based on an average of a 3 to 5 mpg increase, they tend to pay for themselves when renewed on a regular basis.