Bought a used 2008 Grand Caravan SXT two weeks ago, with about 26k miles on it. Driven it around town for the two weeks, and we're averaging between 10-11 mpg.

We aren't driving it hard, the van seems to run great, and no MIL light on. On board computer avg economy is pretty much dead on with basic gallons divided by trip odometer calculations.

Took the van into purchasing dealer for service this morning to try to get to the bottom of it, and they claim absolutely nothing is wrong with the van. Basically telling me that it's my driving habits. First tank we averaged 10, second I BABIED it and we averaged 11.5, WOOHOO! Hate to see how it would have to be driven to reach 17 mpg.

Anybody have any idea what the heck is going on here?

 

fuel leak? Does it smoke at all?

 

I assume 3.8L and 6 speed trans.

 

Yes to both.

I don't believe it has a fuel leak, no smell whatsoever. Seems to be the most reasonable explanation though. It's not going to dump that amount of fuel, without tripping a MIL.

Final word is that they'll have a tech drive it home tonight, then recheck the mileage and all the data in the morning.

 

Yep, that would have to run pretty rich in order to pull 11 mpg.

 

Also, after the first tank, I rechecked everything that was supposedly checked before purchasing the van. Found an air filter that was black as could be, completely clogged.

Obviously that'll cause the mileage to be poor, but even after changing, the mileage has only slightly increased. Possible that it hasn't recovered from that yet? Still adjusting the fuel ratio to what it should be, now that there's actual air flow through the filter?

Apparently I'm the only person on the planet with this issue. First one this dealer has seen at least. And, to top it off, taking a 7 hour drive to Myrtle Beach this weekend. This mileage is going to kill me....

 

do you live in the upper elevations?

 

Nope, Northern Virginia, just outside of DC.

 

I live near fredericksburg va, lots of stop and go traffic

I was only getting 13.4 mpg, v6, 3.8l and I didn't think I drove rough, so I tried for the past 1250miles to keep the rps under 2000 which is very hard when pulling out in traffic, and 60 or less now I am ave 19.5 mpg

I drive 60 miles each day, 15miles in 15miles out, 2x daily
10miles of city traffic and the 5 of country highway which has a 2 stop lights on that stretch, so it is hit or miss weather I have to stop or not
if you ever check your rpms when accelerating they get over 3000 real easy,

 

Second tank, I didn't get above 3000. No hard accelerations whatsoever.

If I were getting 14-15, it'd be one thing, and I'd probably assume it was driving habits. 10-11? That's not even close to the target mileage.

Anyway, when I get the van back today, with the assumption that they find nothing wrong, I'm going to go ahead and do a BG fuel induction service to see if that improves anything.