According to the avg mpg on my durangos's computer I am getting about 2-3mpg less in my new/used '06 5.7L MDS Durango than in my '04 non-MDS Durango. Any thoughts on what the prob might be?
Thanks!
Mike Yates

 

I was told that the overhead console is inaccurate,
FF

 

Fascistfaction is correct. Almost always inaccurate.

The only way to gauge your fuel consumption accurately is miles driven divided by gallons you pump into the fuel tank.

 

First of all, as stated, ignore the overhead and hand calculate. That said, most Hemi Ram owners report better gas mileage AFTER turning off MDS (with a tuner)...

 

ok prob a dumb question, what is MDS?

 

Multi displacement system...I believe shuts cylinder fuel supply to uneeded cylinders when on highway to conserve fuel.

 

It shuts down four of the eight cylinders by filling them with air only. No fuel or spark until you press on the gas in order to pass or climb a hill at highway speeds,
FF

 

Mike:
+3 on the overhead console not being very accurate. You should find that you can use the reset button to bring this reading back to zero for a fresh reading, but the old gallons used per tank vs miles driven is still the best method.

Re the MDS, depending on your personal driving style, you may see little to no difference in the mpg of your D.

Hopefully you are running the required 5w20 weight oil so the system can work as designed.

Your best shot at seeing good mpg will be steady state cruising (no towing) on the highway. Some folks have reported 21-22 mpg with MDS under these parameters.

If you are lead footed, keep a lot of crap inside, or live in a mountainous area, the MDS will engage rarely.

My 04 Hemi SLT usually returns 13 mpg around town and 16-18 mpg hwy depending on how my luck is running.

This is with the 3.55 gears. Don

 

I use the cruise control for my daily commute on the turnpike and that seems to help along with the MDS system. I never tallied my gas mileage which is strange as I am a controller,
FF

 

Do both of your D's have the same gear ratio? I am not even sure if there was an option for 3.92's on the 2wds...