Sudden drop in MPGs?

Have you had the rev1 trans flash yet? Mine dropped too around 2k miles and since getting the flash it has been going back up

 

Mine dropped about 2.5 mpg three tanks ago; starting to see it come back a little on the current tank.
I'm chalking it up to winter blend.

 

Mine hasn't changed, I usually get better mpg in the winter because I don't drive as fast.

 

There is definitely a drop in efficiency as weather changes but not nearly enough to account for what you're seeing here.

 

Depends...
For every 10 minutes I idle, I lose about 1 mpg from the tank average.

 

I got my truck in August, 16 TRD Sport DCLB 4wd, I took it on vacation, bed loaded down, with stuff for a beach trip, wife and 90lb dog, I averaged 20 to 22 on the trip, mainly interstate and highway 55-70. At sea level I got 24 driving around on level ground. Back home I have been getting around 18.5-19 before the weather cooled off on my normal drive to work and errand runs, now that winter gas and cooler temps are here mileage went down to to 17-17.5 mpg, the real cold temps the other day 9-15 F, the computer was at 14.2 on my 8 mile drive home thru town at 25-30 mph. I always check my mileage from the odometer and pump at each fill up, it is usually a tenth or two higher than the dash readout.

 

Well yeah I guess if you all are idling your vehicle that long to warm up, but that's silly if so.

 

I experienced this same thing before the change in weather. I'm not convinced it is due to the cold weather or "winter blend gas". Went from 20-21 per tank to 16-17 per tank. It's worth mentioning this drop occurred right after I brought my truck in for a 10k service.

Somewhat related, how is your experience in the third gen with coasting? I find that in my truck when I take my foot off the gas, the tendency for the truck to slow down is very pronounced, much more than I've had in my past cars. Almost feels like a brake is partially engaged, although I am running duratracs.

 

That's engine braking from torque converter lockup.

 

Not always...
Driving around with a 1/2" of ice on the windshield is even sillier.

 

Do the 2017's require the flash too? My transmission seems to be doing well; haven't had the issues that the 2016 guys have.

 

My truck is garaged and there's rarely any snow in the lowlands of western WA. I don't idle it to warm it up; I just take it easy until it's in regular operating temps.

 

I know what is happening, just wondering if others experience a very pronounced engine braking.

 

Nope, mine coasts pretty normally for a truck.

 

If I found no leaks, air filter is good, engine temps good, I'd wait and see.