MDS won't kick in at 60mph
 

Hi guys! Just picked up my new 09 quad cab 4x4 with the hemi in it. I noticed around town the "fuel saver" light goes on, but at any speeds above 50mph it won't go on. Is it because its so new? (20 miles on it)? I had the cruise set and there was no wind and on level ground. What gives? Normal?

Thanks in advance!

Well, that is not normal, if I am not mistaken 70 is the magic number where it will not engage.

I assume you are in drive and not manually shifting and your tow haul is off?

Yes in drive, not manually shifting, and tow haul is off. Maybe cuz its just breaking in?

The MDS may take a while to start working all of the time. There was a notice in my owners manual. Same thing if you disconnect the battery.

The PCM needs to "learn" your driving habits. I think.

Ditto.

And there is no magic number where it cuts out, it is all about load. Now in most circumstances, you won't have a light enough load at 70 for it to stay in fuel saver most of the time save for going down hill. I had MDS kicked in at almost 75 last week down hill. Maintaining at 70 it is in about 50% of the time. 67 it is about 80% when maintaining.

No mine will kick above 70-75..

That will be nice. I set the cruise at 75 in MI often. Will probably depend on wind direction.

I have only driven the truck once ( just picked it up today) so maybe it does need to learn. It does come on when i am decelerating from 60mph tho. It says I am getting about 16mpg on the hiway right now, but thats not bad considering it has to break in....I think.....hoping...

watch the water temp gauge , after 2000-3000 the temp will go down some?
Your milage will get better. The Hemi really scared me with thw mpg. I drive 40,000 plus a yr. I am getting better milage each week. 5049 miles now.

sounds good!