I rarely get the light in the city unless a roll up towards a light. On the highway however, I see it on frequently!

 

Finc.jb:
Are you only checking while headed West? Wind may play a large roll, esp. on the wide open spaces.

 

You would have the 3.55 if you do not see a $375 option on the sticker for the 3.92 Anti-Spin Diff.

 

Thank you kindly Sir!

 

My build date and options are the same as seigell quoted here. FWIW, I've noticed the same function of MDS as seigell. We only have 300 miles on the truck. And we have averaged 13.0 MPG hand calculated. I notice the "FUEL SAVER" light on while driving around town when around or over 30 mpg with light pedal pressure. Pretending there is an egg on the pedal is key. But I admit it is really hard to do that all the time. This truck is just to much fun to drive.

 

It's all about averages. Don't look for the light - instead look for the averages. Here's a couple of things that I've discovered re the MDS:

1. It does work - but is only noticeable with the 3.92 gear ratio trucks. On the 3.55's - it's very hard to notice.
2. It will kick in when coasting, driving down hills and steady freeway driving.
3. Wind does make a difference. I traveled 250 miles down I-40 in the Western US on Monday - had a headwind - averaged 16.4 mpg. I traveled the same 250 miles in reverse yesterday - no wind - averaged 19.9 mpg (I have a tonneau cover).
4. You really can't control the MDS well. While you can try to drive like you have an 'egg' on the peddle, if you do you'll have to apply even more pressure to speed up, etc. which will offset any MDS savings.

Lastly - I'm thinking of turning the MDS light off. Why would I want to know? What good is it? If I just drive my truck sanely and appropriately the MDS will kick in when it can and save me gas mileage when it can.

 

A good summary, and I agree. It seems I have the 3.55, and I have great difficulty telling whether it's in or out, exactly as the system promises.

Two more points - I had the system engaged at 78 mph indicated this morning, which surprised me. And, cruise control is more effective than imaginary eggs to me. The pedals override the CC if necessary. Between the MDS, tranny & CC, the truck can work out for itself what it needs to be doing far more dynamically than your right foot. That's why they spent so long and so much on the R&D in this wonderful vehicle.

 

Well I've driven it N,S,E and West and it doesn't come on while on the highway with or with out the cruise on. Am I bummed? Yes. Will it make me want to get rid of the truck due to gas usage? NO! I keep hoping that the truck needs me to drive more highway miles to get the computer used to them, as almost all miles on the truck have been city.

 

My MDS doesn't come above 80km/hr....I only have 2500km on the truck....

 

This does not appear anywhere in the manual (I just checked), but, it is possible that you do not have this display turned on.

If you have the EVIC (electronic vehicle information center) there is a setting panel that allow you to choose all sorts of options -- if the horn beeps when you lock your truck, if the side windows tilt downward if you put the car into reverse, etc. One of those settings is the Fuel Economy Display. This has to be checked and turned on for it to display in your EVIC when activated. You should probably check that.