Hi all,

I have a question about the Miles Qer Gallon guage on my minivan. Is it accurate because According to the the on dass gauge I'm not getting the milage i should be getting. I'm only getting about 15 miles to the gallon. Not much better on the highway only about 19. Is this a common qromlem. If so what can I do.

 

That's tough to answer without knowing a bit more.

What size engine and what transmission do you have? What kind of driving do you do? Is it stop-and-go traffic or all highway? If it's a mixture of the two, what perentage of each do you do? How do you drive? Do you push it or just cruise along at a moderate speed and easy acceleration? How much of a load do you usually carry? Are you alone or do you do much of your driving with a load of passengers or cargo?

My 2010 T&C Touring WPC edition has the 4.0 liter engine with the six speed auto. I get about 19 mpg going to and from work. I can get up to 26-27 mpg if I cruise at 55-60 mph on the highway. The computer seems to be fairly accurate from my experience. It took six months or more before the mileage seemed to reach it's natural average. The first few tank-fulls, the mileage wasn't very good, but everything was tight and I was naturally accelerating rather slowly with the new car.

My 2007 T&C with the 3.8 engine and the four speed auto would get a little better mileage, but it would go into top gear at just over 40 mph. With my 2010, it doesn't shift into sixth gear until you hit almost 55 mph.

Your car will get it's best mileage at the lowest speed you can drive in the top gear. That's when it will turn the fewest engine RPM's. My drive to and from work averages right around 40 mph. I used to get a couple of mpg better with the 2007 due to the different gearing, engine and the 2010 weighs a bit more than the 2007 did.

Even the way you accelerate can affect your mileage in ways you wouldn't think are correct. In most vehicles, with a gas engine, you'll actually get better mileage if you accelerate at at moderately good pace and get to cruising speed quickly. A cylinder on a gas engine burns just about the same amount of fuel whether you're at full throttle or part throttle. The stoichiometric mixture of gasoline and fuel is a fairly narrow band. It's not like the old days with a carbureter that would just dump a bunch of gas into the engine when you pressed the accelerator. Modern fuel injection systems and computers keep the air/fuel mixture very close to the ideal range at all throttle settings. Accelerating at a very slow and easy pace, the engine has to pull the pistons in the cylinders that are on the intake stroke, down agains the intake manifold vacuum. A throttle setting that's more wide open, lowers that vacuum and puts less of a load on the engine.

Basically, driving in a manner that will turn the fewest RPM's per mile will give you the best mileage. That usually means the lowest speed at which you can keep the engine in top gear. On my 2010, that's about 55 mph. On my 2007, that was just over 40 mph.