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My 2010 grand caravan's mileage horrible

67-70km per 15liters!
Used to be 11liters for 100km!

Help pls!
I dont know what to do and i dont have a trusted mechanic i dont wanna get r-off.

Thank you

A few questions:

-How are you measuring the mileage?
-How long since the car’s been tuned up?
-Is the check engine light on (or flashing) and have you had the codes read?
-How does the vehicle run and drive?

For those of us in the flash card section, that’s 21 mpg to 11 mpg.

@Autodummies, how many miles on the van, when was the last service, and what was done?

Usually weather, and short trips wreck mileage.

We cannot help you without more detail. You haven’t even told us how many miles it has or which engine is in it. As of right now, everything we say would be a wild guess. It could be anything from a stuck brake caliper to a dropped cylinder to your neighbor playing a siphoning prank on you.

Click the “Mechanics Files” button at the top of this page to find a good mechanic.

p.s. I think that buton could have a better name, like “Find a Mechanic”.

When there’s a sudden drop in fuel mileage, the first two things to check for is either a thermostat that’s stuck open or a coolant temperature sensor for the computer sending a faulty signal.

If thermostat is stuck open, the coolant doesn’t reach the proper temperature for the computer to go into the closed loop mode. The computer then thinks the engine is still cold and the engine uses more fuel.

If the coolant temperature sensor for the computer sends a faulty signal, the same thing happens. The computer thinks the engine is still cold and the engine uses more fuel.


Last service was 2months ago, oil change, coolant, steering fluid. Stands at 111,*** km. no check engine lights or whatsoever, it runs pretty good. I fill it up with 15liters of gas then did the “trip A” counter. Its a 3.3 v6.

Thank you so much guys. And apologies. i’m “Autodummies”. literaly.

Too few liters of gasoline to figure out fuel economy. If you had short trips instead of highway miles, the economy is going to seem worse than you should get. Try 60 liters in mixed driving and you may get better results. 60 liters on the highway will be much better.

One more question, is the chime sound normal when i turn of the engine? No lights on, doors closed. Thanks again.

Note*** they put it on the computer thingy when they serviced it. And everything is good except the fluid flush. And they did fix it.

Make sure your tires are inflated to the pressures listed on the door jamb as well. If it runs good and the check engine light isn’t on, I’d suspect that somehow you aren’t calculating the mileage correctly. A good running vehicle doesn’t just drop to the mileage you’re getting. If you reset the trip counter at the last fill up, next time you fill up calculate it again. Is it possible the counter got reset somehow? If the battery was disconnected as part of the service you got, that could reset it.

Does your car have the digital display next to the speedometer? Is there anything displayed when the chime occurs? A chime when you turn off the engine might be telling you to check the dash for warning lights, or it may just mean you’ve left your headlights on–though you’d get more than one chime for that.

You need to go through at least two full tanks of mixed driving to get a halfways accurate mileage figure.

Make sure you tank at the same station and THE SAME PUMP!

Note*** they put it on the computer thingy when they serviced it. And everything is good except the fluid flush. And they did fix it.

I don’t think the “computer thingy” tells anyone to flush any fluids. Ask friends about their mechanics and look for a new one.

Did fix what?

Where can i find the thermostat in my car?

Follow the top radiator hose to the engine. That’s the thermostat housing.

As stated, your method of determining fuel economy is flawed.

My car and others seem to be suffering poor mileage, perhaps it is just the cold weather, or a different gas blend. I have never gotten less than 16 in town and down to 12, no cel, no issues.

Barky, that’s pretty bad. From 16 down to 12 is a 25% loss. Are you sure you don’t have a stuck open Tstat or bad coolant temp sensor?

@jesmed yes I am sure I do not have a tstat problem, replaced it 2 years ago due to cel for low temp, temp is good, I thought maybe because the last oil change as I have gotten lazy and old, they set the parking brake that maybe the brake was dragging, so I suggested a rotation with my guys, and check to make sure no parking brake problem. No problems, no stored codes, all wheels freewheeling fine, and one of their mechs with the same car, same thing. Sure I know it sucks gas, but like my great grandpa said if you need eggs, you have to buy them, If I need gas I have to buy it. PS New Air filter and gas filter in sept, and total trans fluid service in august, come spring differential and transfer case fluid change. I usually use a block heater 15 deg and below, I think last year I used it twice, probably 15 times I have used it this year, and with a high of 14 below in the day I used it at work 5 cars no start after work that day.