I have a 2006 Caravan 3.3L SE and the last two times I have gassed up, I have got a pathetic 13.3 and now 11.75 mpg respectively. Temps have been very cold here, on average around -4F and most of the journeys made are around town and have been around 10 minutes long from a cold start. Does this sound normal? I have also been using cheaper gas with a 10% ethanol content which I have now stopped using.

 

Well, there's a lot of variables which will greatly effect fuel milage such as warmup time, short trips (they greatly suck up fuel), tire pressures, driving habits, Someone stealing gas out of your car, tune up, air filter, cracked flex plate, driving in snow, thermostat, and so on. So eliminate the simple obvious stuff and go from there. I have an 03 T&C that drops about 10-15% in winter. You should also realize that winter blend fuel does reduce fuel milage plus oxygen content of cold air is higher which the PCM will richen the fuel to maintain a stoichiometric air fuel ratio.

 

tires pressures are good but there has been a lot of snow here. I guess i'll see what I get out of this tank full and go from there. I remember getting around 19 miles last time I checked before it got cold. I'd be interested to see what other people are getting though. Thanks for the reply.

 

In winter I'm getting 18-19 and in summer 22-24 with an 03 T&C 3.8

 

There is no such thing a fuel economy in cold weather.The engine runs in a full rich mode untill it gets to closed loop and that can take a log time in cold temps.I too live in cold weather and do not even think about checking milage.In fact I use a lot of fuel allowing it to run and warm up daily!

 

Great for you but I still measure fuel milage. It is an awsome tool to confirm the running condition of the vehicle. My van has a moderate drop but not of a concern to me. I also have an import car which in warm weather averages 38mpg, and in winter, I'm getting 35mpg, to me this is an insignificant change. I don't let my vehicles warm up!!!, I just get in and drive. I can do this because they are kept in a heated garage set at 60°F. Absolutely, the vehicle has lower fuel milage in winter, but not because of a 'full rich' mode. Infact, EVERY time you start your car (especially cold) it is in rich condition until the oxygen sensor comes online AND normal operating temperature is achieved. The reason for poorer fuel mileage in cold climates has to do with oxygen density and that cold regions have a different fuel blend in winter for improved cold weather start. BTW buying 'HEAT' or ISOheat or other gas line anti freeze products, in northern climates is a waste of money since the fuel already has it... and if you're in a region with ethanol blended fuel, the alcohol does the same thing as the afore mentioned products.

 

Considering your short trips (10 miles) in -4F temperatures with 10% ethanol in your fuel, that mileage may not be unreasonable because you have three strikes against you.

First, the short distance. Even in milder weather, half your trip will probably be in open loop mode. Plus, I would suspect these 10 miles aren't cruising on the highway.

Second, the ambient temps. Being that cold (and if you don't use a block heater), you might be in open loop the entire 10 miles running richer than in closed loop mode.

Third, ethanol is OK from the octane sense, it has less "energy" than straight gas and your mileage will decrease just because of the ethanol in the fuel. I don't know if 10% ethanol directly translates to a 10% drop in fuel economy or not. Plus the winter fuel blends (for easier starting) also decrease mileage.

I live in Maryland and while we can get down to the single digits (F) in the winter (such as yesterday morning), our van (2005 SXT short)) with a 3.3 V-6 is averaging around 19.5 MPG this winter.

Three key points for gas mileage:
(1) Minimize rolling friction (tires, brakes, etc.)
(2) Maximize engine efficiency (proper oil, tuneups, etc.)
(3) Driving style (throttle use, traffic conditions, etc.)

I can easliy get 2-3 more MPG than my wife purely based on our drivng styles and conditions (I have longer drives than she). I have my fun in my '98 DOHC Neon pulling 7200 RPM (manual) upshifts. In the van I try to let the transmission upshift by 3,000 RPM.

 

temps are still very cold here ( in the -Fs )and I got just under 12 mpg for the last tank full. All journeys are around town, no highway and all under 40 mph and around 15 minutes long at most. Car is driven constant throttle deployment and I let the transmission change up by itself. I stopped using the engine block heater since we moved into a home with a garage. I guess I am going to plug it back and see if it makes a difference. I'll get back with the results.