Ok there is just way to many postfor me to read about this. i'm actually getting worse milage with it then my friend with is 03 fully loadedbed gets. i get 11mpg with 87 and 13-14 with 93. I also have a K&N intake and a Flowmaster exhaust. I mean come on my camaro witha built small block gets better milage then my truck and that has almost 400 hp. Also my truck is "EATING" antifreeze. it's not leaking from anywhere and it's not getting into the oil. but i go threw a gallon just about every 6 weeks or so. i also have almost 20,000 miles on it. has anyone else had these problems? Also when i bring it to the dealer they say nothin is wrong, they won't do anything for me. Don't get me wrong i love when i but it to the floor and tires roast and it throws you back and just launches off. I love the power it has just wish i could fix my problem. any suggestions?

 

I get 9 mpg with my usual "spirited" in town driving. It isn't just driving habit though, as on the highway at steady speeds of ~ 70 it improves to maybe 12 mpg at best. I'm going to do plugs & wires soon (55k miles) but I'm not expecting miracles.

 

it simple to fix. hit your od off button and mds goes away

 

man i cant believe your getting that bad of mileage with MDS, i am getting about 14 around town when i keep my foot out of it and about 18-19 on the highway between 70-75

 

I have none of those problems . Sure it is heavy on the gas but when you think of all the things you can do with your hemi i dont think i would trade it for anything ... well maybe a cummins but thats another story

 

Do you smell coolant at any certain times....like WOT or idle? Since you don't see it dripping anywhere it has to be burning off before the coolant hits the ground.

Driving habits is probably why your mpg is so low along with whatever truck configuration you have...4x4, quad cab, etc

BTW what year is your maro and what mods do you have done?

 

Well... let me guess at this... you have changed the exhaust... so therefore.. you hear it when the MDS kicks in.. you don't like it... so you romp on the gas pedal till it sounds better....now now... don't call me an @ss... I do the same thing... droped the stock muffler and put in a Magnaflow.... sounds good at an idle.... sounds good on take off... but at cruising speeds... horrible... just horrible... that may be one of the causes of your poor mileage..... I have a 07 Quad cab... with a loaded tool box... city... i'm gettin anywhere from 10 and up... and on the highway... i'm gettin anywhere from 15 to 22.....AM i wrong?

 

I had a Ford Taurus (no more Fords for me after that car) that I had to keep adding coolant to, no leaks and never saw or smelled a drop of antifreeze. Car hadabout the same mileage when I noticed the problem, it turned out to be a bad head gasket. The car ran fine for about 30,000 miles, the car had just over 50,000 miles on it when it when it leaked enough to cause problems.
The thing had a very small leak on the head gasket, near the exhaust and the antifreeze was burned off as it leaked. If you are adding antifreeze often, there is a leak somewhere.

I like the MDS, I get between 17-20MPG with my 06. You have to keep it in MDS to get good numbers. I bought my truck used and it had a Flowmaster on it, and it sounded like crap when the MDS kicked in. I just installed a Borla cat back system, and it sounds great, absolutely NO drone.When the MDS kicks in, it isn't annoying.

 

Sorry, I don't get the connection. Why blame MDS for a coolant issue? My 300C gets great mileage (for a 4200# car with a V-8). I suspect the highway mileage would suffer considerably without MDS.

 

A lead foot equals bad gas mileage. I drive my truck like a truck, not a race car at Bristol. I get 16 mpg around town. I don’t go around lighting up my tires and I run stock exhaust. The MDS works fine and I can’t tell when it’s active or not. Maybe it’s just my driving style. Red