Truck is a liar - mpg

I have done a lot of fuel mileage testing with my truck. After 6 months I can confirm it burns every drop I put in the tank.

 

I'm going to check mine on my current tank. I filled it up, reset the trip, and the onboard mpg. I'm at half a tank and it's "showing" 13.3 mpg.
It's definitely wonky. I've ran it down to 5 miles to empty and squeeze 29-30 gallons. Last tank was hand calculated at 12.9 and onboard showed 14.2 mpg.
I didn't buy it for mpg. But I would have thought it would have done a bit better. Or at least properly indicated mpg and dte.
Truck is completely stock.

 

Where? Sandstone can play hell with the MPG.

Well this is my first MPG post I have anywhere from 12.3-14.4 running back and forth to work and now back and forth to my hunting spot.
Yesterday I had the opportunity to really get an accurate highway MPG from St. Albans, WV-Dulles International and back. Route has a lot of hilly terrain and I wasn't in a hurry so cruise was set at 65. To Dulles I'm think is more downhill than up but the numbers don't lie 18.8. Dulles to WV 17.3 for a total trip average of 18.1
All I know is this beats my 06 Taco 4.0 hands down.

Oh yeah almost forgot not to get off topic. Average Fuel Economy has never been right or even close. When I left on the trip I didn't reset and it was setting at 13 something ended at 15. Hand jammed 18.8. Reset on the way home ended 18.8. Hand jammed 17.3

 

Yes, all stock the bug hasn't really bit me yet and have other obligation. It's only 2 1/2 months old with 3000 on it. I was pleasantly surprised.

 

Thank you for the details info.

 

I live north of Charleston WV and it's not anything like southern WV as far as terrain. We just took a trip to Gatlinburg TN (350 miles one way) in the wife's Expedition. It's an Ecoboost. Loaded with 4 people and luggage it returned 19.4 mpg. And those that have driven the WV turnpike understand there is constant elevation changes. Highest I believe is 3200ft. It just went up the hills in 6th.
We almost took the Tundra to put miles on it as I am running under the lease mileage. But 6 miles per gallon difference made the decision.

 

Here's my last tank.
378.2 miles
DTE indicating 12 miles
29.583 gallons to the second click on pump (same as last fillup)
Truck indicated 13.3 mpg
Hand calculated 12.78 mpg
Same station and 87 octane

Truck is a completely stock 16 Crewmax 4x4 with the 5.7
Reset trip and truck indicator at last fillup.
Half highway and half country road driving.
Looks like this is where it's going to settle in as last tank was 12.9.
Not complaining- just sharing my results.

 

I'm stuck at 12.9 regardless in town freeway 60--75--80 She just sucks gas but hey we knew that when we drove her off the lot right

 

Thanks for sharing...
This is my my last tank on 2014 Tundra 5.7 with TRD supercharger but everything else is stock. (I don't have a heavy foot)

244.5 miles
20.490 gal
Truck indicated 16.7 mpg (reset at last fillup)
Hand calculator 11 mpg
92 octane.
In town driving just to work and home.

I still can't figure out why truck indicator is so inaccurate.

 

Ask @cdkenne

 

My truck is stock 2 months ago added a tonneau cover but I don't think this make a big difference if any, This are all my fuelups from last 5 or 6 months I think and the pattern is almost the same in every fuelup, anyway I love my truck no complaints I always used 89 octane in every fuelup a exemption of the last one were I used 91 to see if make a difference but don't think so.

 

Nice truck!!!

 

Thanks, your 1794 is gorgeous, that was my second choice for a Tundra

 

My computer read 13.1, I calculated to 11.9. that's not too far off. that's all city stop and go. and I don't even care. my tacoma for 15-6
16 or so 13-14 in the winter. I also use my remote start a few times a week. all good

 

I think being 10% off is way too far off, but maybe that's just me.

And yes, have noticed my winter mpg has gone down from 18 overall to only 15.5ish

 

My truck average MPG and my BullyDog GT don't agree on the MPG/ Bullydog is higher than what the truck says...