402 miles on 89 octane BP, 22.7 gallons...........not to damn bad

 

With a little over 5,000 miles now, I'm averaging about 16 overall and that includes lots of mountain driving.

 

You guys have me thinking somethings wrong with my truck. I have the 09 Laramie Crew with 24K miles and I'm averaging 11.7 MPG. I do have the level kit, 24" magnaflow, Undercover SE tonneu and 305/55/20 terra grapplers but that should not throw the mileage off that much? I've never really heard a difference in engine sound when the mds kicks in. Wonder if that system is not working? My truck sounds the same all the time...

 

Screwed up the exhaust and put on heavy tires with high rolling resistance - sounds about right.

As for the MDS - does the fuel saver light ever go on?


Mine has 46K on it and I get around 15 in the winter and 18 summer, mostly highway

 

no I don't have a light that indicates the MDS working? Was just reading another thread about that and may need to get my truck flashed? Screwed up the exhaust? I would think it would breath easier with a performance oriented muffler..... Tires, your spot on. I would expect a small loss from a wider heavier tire...

 

Breathing easier can = less back pressure which doesn't = performance. Usually loud muffler = more exhaust restriction any ways.

Ever notice that these "performance" mufflers never have any dyno results to go along with them, just noise.

 

Interesting observation.

 

When you take away back pressure you start messing with the MDS system. I had an 08 1500 and went to Toyo M/T 33" tires, instantly my mileage dropped from the 16's to the 13's, so yes it makes a difference.

 

Its fine you killed your mileage with the big tires...heavy, takes a lot to turn those big *** tires.

 

There is a flash for the early build 09's that did not get a the fuel saver light, it does nothing to your truck other that make the light come on when the MDS is functioning and don't worry you are not supposed to hear it engage, you are lucky like most of the early build ones are seamless, the newer ones seem to be the ones that are experiencing issues with noices and droaning exhaust etc. I think people worry too much, if they hear one guy is have a vibration in the gas pedal all of a sudden everyone else does too. I must say this truck has only been in once for some thing other than maintenance and updates.You really might be behind a few RRT's from the sounds of it that one was 10 or so back give or take a few.Doesnt your dealer tell you or maybe they just do them and don't bother, check your oil change receipts, every once in a while I will see RRT number such and such performed. After 3 years unless you have a gold plan warranty RRT's are no longer free and I am not even sure about the gold plan if it covers RRTs