My Durango - need fuel efficiency tips

durango · #1 08-30-2009, 11:21 PM

I recently purchased 2006 5.7 Hemi Dodge Durango 2WD.

Based on 2 refills so far it seems it's averaging 13MPG ... which is very scary to me. I looked into several articles, sites. Checked air pressure, coasting, not not to speed and braking, staying under 70 speed limit. Still testing but what are some other tips would you recommend? I appreciate any help, this is my first 'big' car.

Thanks!

Elixer · #2 08-31-2009, 02:49 AM

Read the basics: http://www.cleanmpg.com/forums/showthread.php?t=1510
Then read them again, and again. It's all there and it's possible to get really big gains if you're willing to study and understand.

In such a big car however with such a huge engine, even using mastered hypermiling techniques will probably never give you really great numbers. I think 20 MPG would be about the absolute limit without making really drastic and probably unsafe changes to your driving style.

A lot of people don't want to hear this, but the best hypermiling technique for trucks is to only use them when you need to. Use a smaller car for commuting and then only pull out the truck when you need to haul a large load or tow something large.

That aside the techniques that will give you the biggest gains in FE in such a vehicle are DWB and DWL. Think about anticipating far ahead what you are going to do, and concentrate on not giving your car any more gas than you need such that you don't have to use the brakes. On the interstate reduce speed. You'll probably get optimal steady state fuel economy around 50 mph. So the slower you are able to go on the interstate (traffic allowing) the better FE you'll get. Of course in all cases keep safety in mind!

Taliesin · #3 08-31-2009, 08:54 AM

Quote:

Originally Posted by Elixer

On the interstate reduce speed. You'll probably get optimal steady state fuel economy around 50 mph. So the slower you are able to go on the interstate (traffic allowing) the better FE you'll get. Of course in all cases keep safety in mind!

By all means follow the link and use what is there.

However, at least in my trucks, the best steady-state FE comes around 30-35 for manual (in top gear).

In trucks, speed kills FE very quickly. and automatic transmissions don't make it easy when they only get top gear with torque converter lockup at 55 (that's where my Ram gets it).

I haven't been able to use the SG in my Ram yet, so I can't give you really good info there. I do know that I usually got 15 mpg when using regular gas (I haven't driven it enough to know more since I started hypermiling).

SD3_Driver · #4 08-31-2009, 06:12 PM

it will be a challenge to get that vehicle to be fuel efficient, so maybe another car is the better solution ...

JusBringIt · #5 08-31-2009, 06:16 PM

pulse and hangtime will benefit you a lot, but you would have to master all the techniques in order to bring the durango up to 20mpg...it'll have to be somewhat warm weather too. Good luck.

brick · #6 08-31-2009, 06:55 PM

KEEP_IT_ROLLING! I have had the "opportunity" to hypermile a few big, thirsty vehicles and that's the most important thing in my opinion. Acceleration kills you, so plan way ahead and try to avoid slowdowns. And given the aerodynamic profile I strongly recommend keeping highway speeds to a minimum.

Unfortunately the Durango has a well-earned reputation as one of the least efficient vehicles available, even amongst its peers in size and weight. (My knee-jerk response was "set it on fire" but we really aren't that kind of site. For all I know you use it to haul around 8 people every day which would be justifiable. And if you just drive yourself around in it then you don't need me telling you that's ridiculous.) The best way to stay motivated is to remember that even 1mpg when your baseline is 13 is a significant gain. So shoot for two and see what happens.

Just be patient and above all be safe.

Die2self · #7 08-31-2009, 07:32 PM

I have the 3.9L V6 Dakota 4x4 and My combination is 15 MPG, Before starting was not a speed demon (most of the time) anyway and was get 17-19. I am now on my 31st day of over 22.5 MPG and my last tank was 24.4 MPG over 450+ miles. It is possible to get in the lower to mid 20's and with more coaching and time I think I could get 30 out of it, but that would be very hard. I have been working on some Pulse and Glide (as I have a Manual) but most of the time it is in pulse hang time in town. As stated above Acceleration is a killers for us with large vehicles even when accelerating slowly, which sometime just seems to drag it down even more. Just stick to it and see what works, faster accel, but try and keep the RPMs under 2000 and force the trany to shift earlier. Or use the slightist touch on the trottle and try to keep the MPG's as high as possible.

Welcome!

Taliesin · #8 09-01-2009, 07:24 AM

I think the first thing we really need to know is which transmission you have. That will let us know where you sit now and what skills work best.

I take that back...

I was just looking at fueleconomy.gov and it seems that the only tranny you can get for that is the auto.

I'm almost lost at this point. My first move would be to get a ScanGuage attached to it and see what kind of speed works best for it.
That will also show you what kind of fuel you are using in idle. With an engine that big, shutting off at stoplights and, shortening the warm-up time, and getting it off early on arrival are all very important. Idling with that one will use a lot of fuel to go nowhere.

Let us know where you are and what kind of fuel you are using too. Ethanol doesn't help much for anyone's fuel efficiency.

durango · #9 09-01-2009, 11:48 AM

Taliesin - I am using 87 gasoline.

jcp123 · #10 09-01-2009, 12:54 PM

Well, I'll admit that already, driving a Mopar puts you behind the 8-ball, their trucks' fuel economy has consistently lagged behind Ford's and GM's fuel economy. Trust me I know - I had a '99 Dodge conversion van once that saw only 12mpg where Ford Econolines and Chevy Express vans were seeing 14mpg.

Check your acceleration - keep the RPM's below 2k when you're accelerating. This will try your patience at times. It's ok once you realize that the other drivers going around you in a huff aren't paying to keep your truck filled

On the highway, as much patience as I know this will take, see what happens when you back the speed down to 60mph as I have to in my Mustang. Though you have the overdrive my Mustang lacks, your aerodynamics, like those of my Mustang, are poor, and backing the speed down will help immensely. I similarly backed down to 40mph on my commute from doing the 50mph speed limit.

Also, refrain from using the air conditioner. Depending on what part of the country you're in, this may be easier than in other parts of the country.

Lastly, take advantage of every opportunity you have to coast. Any small downhill section will do, especially if you opt to shift to neutral while coasting. It's also useful to scan far enough ahead to anticipate red lights and slowing traffic and start to coast down your speed ahead of time - you'll avoid sitting there and waiting, avoid idling time on your motor which burns more fuel than you'd think, and avoids burning fuel to maintain your speed approaching the stoplight/stopsign/whatever obstruction is there.

As a side note, doing these in a relatively crude manner in my Dad's truck, a Hemi-powered '07 3/4 ton 4x4, I was able to raise the trip to Home Depot from ~11mpg to ~14,5mpg.

Similarly, in my Mustang, combined with tuning my carburetor (unnecessary since you have electronic fuel injection), slowing my acceleration, and pumping my tyres up to 40psi, I have gone from ~14mpg to ~17mpg on my commute.