Huge drop in MPG

[14HighCountry]

About 10 days ago I took my truck to the dealership to get oil changed and they did the recall about the transfer case shift to neutral. Before I took the truck to the dealership I was getting 17.2 MPG average. Now I'm barely getting 13.5 MPG average. Any ideas about the huge drop in mpg?

[TheFactor]

Maybe your average dropped from the truck going in for service and it was idling for a long time . Have you checked from setting your trip for the miles you've recently drove to see what your mpg is in that time frame ?

[14HighCountry]

I have drove 1300 miles since the service. I'm getting 80-100 less miles per tank. I haven't done any mods, get gas from same station, and driving same distance

[MMC]

^ This mine idled for over three hours while they loaded the software. Cold temps and winter blend fuel also lower MPG's.

[BIGDOGx]

Winter blend fuel maybe, also we have had quite a temp change across this country this last week.

 

Lol should of scrolled down to see MMC beat me to it.

[stevev]

I lost 2mpg with this cold weather and winter blend gas. My Uncle with a Ram Hemi told me he's down 3mpg recently too.

[bladz1454]

+1 to the winter blends. I purchased my truck last November when winter blends were already out and was on here b*tching about my 12-13 MPG out the gate but I shut up pretty quickly in the spring when I got 16 city and like 21 hwy. Granted my lifetime MPG in 12,000 miles is still like 15mpg hehe

[TJay74]

Some shops run the truck while the updates load, my shop plugged in a battery charger when they loaded mine. I would ask your shop about it, running the truck the entire time is bad business in my eyes.

[srphoenix]

Yeah, this truck doesn't like under 35 or so for fuel mileage. I have the 3.08 gears and mine goes from averaging 19-20 in combined driving down to 16-18. I'm sure the winter blend fuel has something to do with it too. At least gas is cheaper again! (either way I still get about the same gas mileage as I did with my Evo X, lol)

[TJay74]

I have noticed just with the cooler temps alone my MPG has dropped with no change in driving style. Just one of those things, more than likely the ECM runs a richer fuel mixture once the IAT sensor sees the cooler intake temps.

[BigBadSierra]

Mine dropped to 15 mpg.. Of course I think it's due to the high Winds and having the 4x4 on everyday ha ha...

 

Still doing better than my Brother in-law 2013 Silverado 4x4 he has been in the 11-12 mpg range this week.

 

But been fun bashing through the snow drifts...

[LS 1st Gen]

Mine dropped about 1mpg average after the Tcase recall. They must have flashed a new ECU update or something.

[Ventilator]

Mine dropped after the T/C recall, Odometer peek, side seat air bag recall, but it was getting better until the WB gas and cold weather got here. So now it will be next spring/summer before I know for sure.

 

I know they didn't run my truck while doing the downloads, because I checked the Hour Meter before and after. The whole thing took about 3-4 hours, including oil change and tire rotation.

 

When I have my tin foil hat on I wonder if they are collecting data, and controlling our MPG through these updates/downloads? The better they do now, the better the gov't will want them to be later. I think they are milking us along on the MPG, kind of like the computer companies do? Tin foil hat off.

[glcbn]

When I had the transfer case and "peek in" done my mpg went all to crap too. But it recovered back to what I was averaging within a few days.

 

What really sucks is how much (mpg) I'm losing now because of the changing seasons. Winter!

[td33]

I can't help you with the mileage drop, but my truck has over 15,000 miles, my overall avg since new is 17.7, also tow a boat during summer months. I make sure I use the the 355 HP it has, love the power it has and real happy with the mileage its getting.