blownlt1bird

OK so I have a 09 GMC Sierra 4x4 crew cab with 24000 kilometers on it and have never gotten any better than 15-16 mpg. In just the last couple of weeks it has developed a stalling issue when I stop at a light. I took it into the dealership to have it looked at and the dealer just called me to say that the truck is repaired. I asked the guy on the phone what they found wrong with the truck and he told me that they changed the mass air flow sensor. It has allready been changed once at about 11000 kil. which I informed him of.
Anyway my reason for the post is that he told me that I would never get optimal fuelk mileage out of my truck because I have a cap on the truck, bug deflector on the hood, vent visors on the 4 doors and last but not least aftermarket catback duel exhaust.
So has anyone else heard this kind of a crock of s..t out of their dealer?
I did inform him that he can on no uncertain terms tell that crock to someone else that doesnt have a brain in their head.

fredkj3

iTrader: (1)

man you are going to have to tell us a little more... what engine/trans/gear is in the truck...
and yea that sounds like a croc

Bow-Tie-Beast

Out of the things you listed, the only thing that I could imagine that would be throwing off mpg is the bugflector and that's only bc it effects the aerodynamics but I don't think it would really be significant. The added weight of the topper could too buts that's only 200 lbs and it also HELPS with aerodynamics.

Proove him wrong and take it all off, bsides the catbacks, and see what you get. Its the only way you will know fer sure

smokeshow

iTrader: (16)

All dealerships sell the same bullshit...they will do anything to wiggle out of having to make repairs under warranty. I think you're getting about the mileage you should get. 15-16 is a fairly accurate average for highway/town driving.

blackjack325

iTrader: (1)

yeah, that MPG sounds about right for intown/highway driving.

get it tuned and a good cold air intake and it should get better.

2007chevy5.3l

iTrader: (21)

Im getting 16.5 mixed driving and thats with a very heavy foot lol.

JAVI05

im getting the same in my 09 5.3 6speed... 15-16 city best ive seen on highway is 16.7. lol.

blownlt1bird

Sorry forgot to mention the specs it is a 5.3 6 speed and I cant remember if the gears are 3:23 or 3:43. I just got the truck back tonight and I do have to say that it does seem to be running better I just find it hard to believe that they have had to change 2 mass air flow sensors in 24000 kilometers I guess only time will tell.
I do plan on getting a custom tune soon I have a diablo tuner and as soon as I get the thing installed back on the truck Im going to make a log and send it off to them to get a custom tune. Anyone have any comments on going that route as opposed to another tuner?