3 months of fuel economy statistics for MT V6 TRD OR. BS will be destroyed.

Exactly. I have noticed the pump I calibrate my scangauge to can vary about .2 to .3 gallons. I have since calibrated by filling the neck completely, which seems to give me repeatable results. I had to recalibrate a while back due to winter blend, and it's back to being stupidly accurate whenever I double check it. At this point, i trust my scangauge over the manual calculation ... but it will obviously start to wander once the summer blend comes out again.

(yes, I am aware that my methods are not great for the vapor collector ... don't care.)

 

I've tracked every drop of fuel in my truck (97 tanks and ~35K miles) and you can check it out on my fuelly. I've tried HARD a few times but can not seem to ever break 20MPG on a tank. I've had a few 19.7 tanks here and there but it doesn't seem possible. Not sure how y'all are getting over 20. Maybe it's the air dam?

 

Is yer tranny full of fluid..?? If you don't know .... check it physically...!! Really... It WILL make a huge difference..!
Next thing is grease yer zerks, fill the rear diff, etc....

That's real bad MPG... I got 28.9 CDN MPG on the way back from BC this summer....!

 

With a manual transmission?

 

OOPPS... no that was with a auto tranny..

 

Shouldn't the manual get better MPG..??

 

Nope. Not the way it's geared, but it pulls hard.

 

Yes, it is with the second gens. Odo is accurate, but speedo reads 3-4% fast on stock tires.

 

I was around 19-19.5 usually (combined city / hwy) with the same truck during the summer and I drive like a grandpa. It's considerably lower right now with long idles waiting to warm up in the winter. The 6MT is definitely not a Prius but I still love it.

 

The BS called regarding the computer is when someone posts a 3 mile trip with 35+ mpg screenshot followed by 10 pages of arguing that their taco gets that mileage.

 

I have the opposite problem... I can't get less than 20 mpg (OR 4x4 AT i.e. no air dam).

Try:
Don't accelerate quickly; but, not too slowly either... just normal.
Shift at like 2300 rpm... don't go above 2500.
Don't go over 65 mph.
Only brake lightly... if moderate to hard you should have got off the gas sooner.
Have at least 30 psi cold.
Don't mess with your phone, radio, A/C, seat belt, etc. after you turn it on or before you turn it off.
Don't cruise around looking for the best parking spot or go to the drive-thru... go inside.
Don't use cruise control if the road isn't flat... it's okay to lose a couple mph uphill.

 

you said it

 

WOW, OP find something better to do with your time, over60 nailed it...

 

The estimates made by the vehicle are never going to be perfect. That is because it is like transferring water from a gallon jug to another gallon jug with a teaspoon, and keeping track by the teaspoon-full. There is a small error in every teaspoon transferred. In the engine, the fuel pump pressure is varying with rpm and the injectors (there are lots of injectors in a 3rd gen engine) are not all the same and do not cycle exactly the same way under all operating conditions.

 

Thanks to the OP for providing an evidence-based test of the truck computer. Very much appreciated!
I checked mileage on a few tanks of gas and it seemed to comport with the truck computer, but I wasn't sure.
My computer-read MPG are consistently 23-26 MPG highway (unloaded) because I drive like Tharris242.
My 2016 SR5 AC V6 is stock except for e-rated stock sized Cooper AT3 tires, adjustable Rancho shocks and Firestone airbags for hauling my camper.
I've driven 22K miles hauling my Four Wheel Camper Fleet around the western US and with conservative driving I routinely average 20-21 MPG per tank, sometimes more, seldom less. Glad to know I can trust my truck computer!

 

I also track all mileage in all my vehicles. Computer is always .2 to .5 mpg off. Never had both PC and HC match. I prefer to hand calculate and put info in fuelly.

 

OP - nice job presenting your numbers. I certainly do not have time for that. Anyhoo, after 18000mi I avergae ~high 21's to low 22's. This winter in this cold ass weather here in NH, I have been averaging high 18's, but I have been in 4wd yesterday as the roads were not ploweed yesterday on my way home. DCSB MT

EDIT: This is according to the trucks computer

 

Point of order! You shouldn't really put any significance on the direction of the trend line with that much scatter and that shallow a slope.

(nerd mode disengage)

 

How do people ensure they are always filling their tank to the same volume to accurately calculate mpgs? Seems to me that the variability in this measurement can partially explain the difference between in vehicle versus manually calculated consumption rates.

Also, as a scientist slash engineer... I am getting skeeved out at all the digits you posted. No way your data is accurate to the millionth of a mpg.

There may be real error in the inboard display, but it's not ruled out that they might be the function of inappropriately using too many significant digits.

 

I thought nerd mode was disengaged..... Just kidding