2012 Dodge Grand Caravan Pentastar
 

I guess this is a bit of an introduction,
I've built and tinkered with vehicles for 35 years, always wanting a bit more performance and more fuel mileage on all of them. I guess maybe my 1986 VW Jetta turbo diesel I left alone because I thought it was pretty near perfect in the fuel mileage department. I am in Canada so I think in the old Imperial gallons, so my MPG figure may sound high for Americans. I am trying to adjust to L/100kms that my Caravan is calibrated in.

I tried to to post a graph of my fuel mileage, but I need 5 posts, so excuse my repeated posts. I'll try to make them interesting reading...

My last new vehicle was a 1999 Caravan and I remember its fuel mileage was terrible (17mpg) on the first tanks and gradually improved over 20,000kms to as much as the occasional 35mpg tank on long flat slow runs. So, I realize I have to be patient and get some miles and a baseline on this new Caravan before I can really prove any mods.

I bought this van because I like to travel and need to haul motorcycles and snowmobiles in all seasons, and I need a vehicle I can camp in. I had a Ford Taurus Wagon and a Jeep Cherokee before this and while they would tow the trailer, they were too small to camp in really, except in an emergency.

I gotta say, this Pentastar engine is peppy. It will scream! 285hp and fly by wire.
It had 100kms on it when I bought it, so for the first 500km I drove it pretty much normally, avoiding cruise control, high speeds and steady speeds. I didn't idle at all, used moderate throttle until warmed up, and then used up to 3/4 throttle quite often once the engine was warmed up. I tried to keep the revs down but 3/4 throttle delivers 6000rpm shift points. I played with the fuel mileage display, using it and resetting it often on the first couple tanks to get a feel what mileage for various conditions is, so I don't have an indicated mileage for the first tanks for this reason.

So, first ten tanks of fuel, speed and indicated fuel mileage on the meter:

http://sphotos-h.ak.fbcdn.net/hphoto...27827166_n.jpg

Any suggestions on what I can do to improve on this besides keep breaking it in and slow down?

I'd look at pre-heating fluids (synthetic, after break-in complete). Same for keeping coolant temps high with radiator cover (winter front) adjustments.

On vehicles specified for work, I think the best plan (past establishing a "perfect" mechanical baseline) is in:

1] Reducing all miles via trip-planning (combining errands, best-order-routing, etc); and,

1] Driving the remaining miles as well as possible.


There is a good deal of depth in those two, I have found. But reducing warm-up time to a minimum is basic to success.

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Have you browsed our lists of mods & driving tips?

65+ Efficiency Mods

100+ Hypermiling Tips

Three immediate steps, in order:

-There should be an "Econ" button down below the radio that lights up a green leaf when you press it. That changes the TCM- it locks up the torque converter sooner and shifts less, even skipping gears. Automatics are funny- if the driver is going to be an idiot, more gears give better mpg. If the driver is willing to take some personal responsibility for it and meet the car halfway, there's a button that will give you fewer gears... for better mpg.

-Pump up the tires. I went up from 35 to 39 psi without throwing the TPMS light. It's my wife's DD and she's not a hypermiler.

-Get an SG or UG. Having multiple mpg displays helps you know what you're actually doing- the longer view, short trip and current values all work together.

My 2011 does pretty well. I reset the mileage back in June and it shows 20.3 mpg since then- which includes a few camping trips with the kids, the dog, a pop-up camper and a canoe.

1/2-3/4 throttle till somewhere between 2000-3000 rpm, let off to get it to shift, reapply as much as possible without causing a down shift and repeat till up to speed.

Good points. I notice the warm up mileage is terrible. My strategy has been to start and go immediately, use about 3/4 throttle to get up to speed briskly while driving heat load into the engine (to get it warmed up), then coast while at speed to maximize miles while minimizing enriched fuel use. This seems to work according to the on-board display, anyone have opinions on this strategy?

Winter is coming, I really like the idea of front covers. Van is designed to operate in Texas, doesn't need that air flow in Canada in January...

Will do fluids after break in, and I am a motorcycle rider so I minimize my cage (4wheeled vehicle) time on purpose all the time anyway. Bought the van at the end of July and it took a couple months to put 1000kms on it!

Yes, I have been a lurker for years actually, followed your projects, and successfully employed pulse and glide driving to get huge (30%) gains in mileage on a Taurus and Toyota Echo. Echo got 80mpg(imp) over a 1000km trip. Experimented with P&G with the Caravan and it will be a viable technique, including engine off P&G, which seems safe and easy with this vehicle. While P&G and EOP&G work, not always practical and looking for what others have found works with their Caravan. Notice on my graph slowing down directly corresponds with improved mileage!

I have to thank you for this site and I intend to be a financial supporter to return what you have given me here. Thanks!

Green Econ light ON! Done. I played with it and honestly cannot see a difference in shift patterns. I have put this down to the van being new and probably has a "break-in" engine/transmission program running for now. Shift patterns are not great with this transmission. Short and long shifts at same throttle setting. Cannot believe MercBenz was behind this development! Again hoping this will smooth with time.

Leary of high pressure tires. Tried this on my Taurus and Cherokee, and besides harsh ride, there are safety and control issues especially on wet and icy roads. I ran as high as 45psi which is unsafe in my opinion and gives diminished returns at top pressures, so I think your recommendation of 39psi sounds wise.

I work for Michelin so I get Michelin/BFGoodrich/uniroyal tires for free, so I will be looking into Low Roll Resistance tires, but I see choices for this van are very limited. I am open to recommendations...

I have been trying that, but this is a "fly-by-wire" system with no feedback to the pedal and the transmission seems to have a mind of its own. Darned thing will go to 6500rpm at 1/4 pedal in some gears and then shifts at 3000 in the next gear. Grrrrrrr! If I let off to get it to up shift, it will hammer back down a gear as I gently reapply throttle to accelerate. I expected more out of this transmission, and hope it will improve with time.

Pleased with the van over all. My 99 Caravan delivered 17 and 18MPG(imp) for the first tanks of fuel so the 2012 is already ahead of that. The 99 eventually went to ~30mpg(imp) after 20,000kms. This 2012 van seems to have lower rolling resistance (although it feels heavier) so I am hoping to get it up into that range.

You have given me some things to work on, thanks guys!

Steve

I just checked. In my 225/65/16 I can get Yokohama AVID Ascends, Goodyear Assurance Fuel Maxes and Michelin Defender Green Xs pretty easily. I'll be slapping a set of Goodyears on it before winter hits.

Funny, the Michelin site rates the Defender as an 8 out of 10 for fuel efficiency?
2012 Dodge Grand Caravan Canada+Value+Package Tires | Michelin Tires

My only winter choice (which I have to make soon) would be the X-Ice® Xi3.
2012 Dodge Grand Caravan Canada+Value+Package Tires | Michelin Tires |Winter Tire

It is rated at 10/10 for fuel efficiency. What is with that?
Winter tires are always less fuel efficient for various reasons.
I work for Michelin but I am a mechanical/electrical guy, not a tire expert.

Does anyone else understand this? (Defender 8of10 fuel rating vs X-Ice®Xi3 10of 10)

Steve