If you are using the digital display to determine mileage, then the remote start period is the main problem for "low" mileage in the winter. You really need to do the calculations by hand to get the true MPG.

 

Not surprised with this mileage, specially with cold idling engine. Eh...my wife's Suzuki SX4 without remote starting and no idling cold turns out 17 l/100 km in winter city driving... that is 17 miles per imp gallon, under 15 miles per US gallon with a 2000 cc engine working on a glorified go-kart....

No miracles in winter....an idling engine gets 0 miles per gallon....

HOwever....complaining the same about my Pontiac Transport 19 years ago (still running) I tricked the engine temperature sensor so that almost as soon as it is started, I switch on a resistor in parrallel with the thermistor sensor that makes the computer believe the engine has warmed up...and this instantly leans the fuel mixture ( to the point the engine coughs if I make it too soon) and that made a tremendous improvement in winter gas mileage. Notice that when engine is cold, the O2 sensors are not used to check emission and it runs on default values making sure the engine will run in the cold...that means RICH....and it smells. IN fact, the engine combustion chambers get warm enough well before the coolant has actually got warmer..which takes some time in cold winter.....so my duty is to inform the computer of that fact....

 

That is why warming up your car is just a waste of gas. They are designed to be driveable no matter the engine temp and when you are driving it will warm up faster. I realize many of us "need" our car to be warm when we first get in it, but it is just a waste of fuel.

 

My SXT has about 2500 KMs on it and I would say I get 9.9 (light load)-11 (loaded) litres/100 KM on highway trips and about 13-14 in town. Those numbers shown at the dealers are junk, you for the most part not get those numbers. I would like to see who gets 7.9 for the highway with this van.

 

Mileage is heavily dependent on driving style. I have no doubt I could get a new van close to rated MPG because I can get my 02 to 8.7L/100KM on the highway. To do that, I set the cruise at 100KMPH and I don't override it for any reason except slowing down. I average at the WORST 12.5L/100KM in the city. If I was getting worse I'd stop driving.

If you want maximum gas mileage you have to drive for maximum gas mileage every second you are driving. I ease into the gas when the light turns green and I let the van shift no more than 2500RPM. I never ever jack rabbit start, not even once. I do not pass. I slow down early. Coasting is key for good gas mileage.

I'm not trying to infer anyone is a bad driver, but 95%+ of people either drive aggressively or just don't care about maximum fuel mileage so they inadvertently drive aggressively. My buddy with a 2011 complains that I beat his mileage alll the time yet he is always telling me how well that new engine pulls and how he seems to be going 140KMPH without realizing it. That is why his mileage is so bad.

 

About fuel mileage improving with miles, it is true.
My 1999 Caravan improved steadily for 20,000kms starting at 17mpg on the first easily driven highway fuelmileage tank, up to highway tanks of over 30mpg(imp).

My 2012 has 4000 kms on it now and has shown a lesser mileage climb (I guess it is a "dip" in L/100kms!):


There is another 4 more tanks after this, one really bad one of about 17 l/100kms and a couple really good ones better then 10. This was just the last graph I had prepared. The green line is the indicated mileage on the display, moderately accurate but not exact.

Speed is a big factor.
Mileage tend to dip strongly after 100kph. I have a graph for this as well:
With more data plots on the graph I believe that line will become a sharp curve.



Or here if you like it in MPG(imp), sorry about the speeds in kph:



This gives a rough idea of the improvement to be had from slowing down.

Stop and go driving is very problematic with the van, very hard on fuel.
The excellent 283 hp does not help, takes gas to use it.

I expect these figures to improve slightly in the next 10,000 kms,
so overall I am not unhappy with this fuel mileage.

 

Hey those are some nice graphs, thanks. I will show this to my girlfriend and try to get her to slow down, LOL !

 

Gosh, when I was young, what I wanted most in all the world was a fast girlfriend!

 

My 2012 Dodge grand caravan SXT avg of 29mpg on a 200MI Trip this week with 27ka on the clock I use shell mid grade, stp additive and a top cylinder lube mixed in the gas for best results

 

ControlI also do very easy take off from the stop lights, leave good distance between cars so not to brake often and control throttle movement, keep speed 60mph or lower and only use the eco button on the hwy , tire pressure @36PSI avoiding sudden stops &starts