ScanGuage not accurate on HEMI MDS

[Harpo]

I drove the 2006 RAM 1500 HEMI MDS towing the 6x12 Race Trailer to Clemson last weekend. I planned my trip well, stayed at 62-65mph on I-75, drafting the slower 18 wheelers when able, then exited in Macon heading up scenic backroads. Overall 13.55mpg for 900 miles. There was some good hills mixed in and about. Stayed off Cruise Control except for some boring flat sections.

The ScanGuage freaks when I go into MDS (4 cylinder mode). I'll be cruising along at 4gpm then when the truck slips into MDS, then FF almost doubles, and instantaneous mileage readout generally doubles as well. It must take avg pulse width then multiply that value to get FF.

I'm not complaining, but just wanted to advise anyone attempting ScanGuage on MDS equipment. You won't be accurate unless you run exclusively in tow/haul where MDS is obviuously disabled, or so it appears. My tow gear is light, so I tow in OverDrive mostly as long as it's not seeking lockup in 5th.

As compared to Civic, it's terrifying the gas it uses. Heck, I can average 40mph in the Civic on what it takes to idle the Hemi.

[SVOboy]

Does the MDS come with it's own FE display?

[Harpo]

Originally Posted by SVOboy

Does the MDS come with it's own FE display?

Yep, but it's useless as it reads 1.5-2mpg high for trip average of any distance as compared to fill. It doesn't to Instantaneous at all. Not until I hooked up ScanGuage could I even model "when it went to MDS." There are no other indicators, nor published condition specifications I can ever find. I hear the $125 service manual doesn't even publish specs.

It was worth the gas money.. I won my Division start to finish as did my oldest son. My youngest son went down on first downhill section, and recovered for strong 2nd. Good racing weekend in front of tons of family! Only bad side was burning 66.5 Gallons of fuel.