Fuel economy

I have noticed a steady improvement on fuel economy on my 2021 4x4 limited. I am at about 17K miles on this 5.7 liter V8. The mileage in this photo was accomplished using an “egg shell” throttle at 65-70 mph on interstate highway. My overall gas mileage for my trip was 19.4 mpg for 561 miles at speeds ranging from 0-78 mph and light wind. Did it on one tank of gas!

I’ll keep my V-8, thank you.

 

What tires you running and what PSI are they at?

 

Was this computer only or hand calculated verified?

Have a hard time believing this.

 

I’m still running my stock tires at 35 psi all around.

 

The photo was taken from the trip computer at a rest stop (about mid-way on my trip) but my final mileage was calculated manually after I filled the tank back up. I have tested my trip computer on my vehicle in the past and it is extremely accurate on the highway. It’s always within .5 mpg.

 

I can get just barely over 18 highway only if I stay around 60-65mph (that’s hand calculated and corrected for 285/75R18s), but there are too many hills around here to do any better than that.

What part of the country are you in?

 

That is a very good mpg figure!

With the cost of fuel being what it is, I decided to change my driving habits this year. I have 12,000 miles on my truck (bought new 3/20) and the best I ever did during the first two years of ownership was 18.9 mpg (both computer and hand calculated came out the same).
This year decieded to slow down and see what would happen. 170 mile trip with cruise set at 68mph on the interstate, then 65mph on the two lane highways for the second half of the trip. I saw 20.1 mpg, while not huge I'll take it.

I'm not a patient person by nature and have always ran with the faster cars while traveling, even 80mph towing my boat sometimes. Trying to change my ways by slowing down (both safer and fuel saving) an extra 15 minutes travel time, no big deal.

 

This was a two day trip from Austin Texas to Wills Point Texas. There was some running around at Lake Tawakoni for a fishing tournament but most was on IH 35 and I20. We have some gentle hills in this region, but nothing super steep. I know steeper hills have a definite impact on mileage. Also, strong headwinds will knock it down too. I do lots of towing miles with my boat and consistency get 15 mpg on the highway doing that keeping speeds under 70, when possible.

 

When you look at the time saved by driving like a madman it doesn’t seem worth it.
I see youre from Eagan. I grew up in Rosemount.

 

That's incredible for 5.7 and 4x4!! Highest I was ever able to get was 25.3mpg, but I was doing mostly highway, 55mph and no AC.(4.6 4x2)

 

Ha, my wife taught at Rosemount high school for years.

 

me too!!!!! The 22.5 figure was my all time best. Had to shoot a photo of it. I think keeping it under 70 is really important to achieve good fuel economy. My engine is turning about 1200 rpm in top gear. I do better if I keep mine off of cruise control.

 

Graduated there in 1990!

 

I can knock maybe 25-30 minutes off an 11-hr trip keeping up with speeders on the interstate. I paid a premium for those minutes.

 

The only way I will ever see this type of mileage in my truck is like this (see pic)....in neutral. It is what it is.

 

@Wallygator no gang, keep her on D. That way fuel shuts off and you get better mileage. If you go off a cliff in neutral, motor has to run and uses gas.

 

Sweet! Thanks for the tip, honestly did not know that. Cool, maybe I could get that mileage. Is there a road down Mt. Kilimanjaro or similar so I could test this?

 

We need to start our little tundra hypermiling group!

 

Best I ever had with my 2018 was 20.12mpg. Best I ever had with my 2021 was 17.08. Not sure why, my 2018 was just capable of better mileage and seemed to have more pep too.

 

2020 5.7 with 20in. I’m new to Tundra ownership. I’m hovering at 13 mpg
can you explain to me what the process of “egg shell” throttle is or how to achieve higher MPG?
Are these modifications or driving changes?

 

Egg shell= light on the pedal.

 

My very best combine fuel economy at the end of a tank:

• I don’t use cruise. It’s not difficult to beat.
• I use S4/S5 around town. In D at city speeds, the truck wants to get to 6th too quickly. The problem is, you’ve got almost no power at really low RPMs (like you have in 6th at 40mph), and it dumps fuel until the transmission responds and upshifts. Way too many hills around here for that. I do much better feathering the accelerator in S4 or S5, staying in a more effortless RPM band while not putting the engine under a load. Sounds more complicated than it is. It’s easy to feel, though.

Were they both stock trucks? Same bed/cab configuration? I don’t think there’s anything inherent in the 21s that give them worse fuel economy. Was your 21 heavier (higher trim, sunroof, mods, or bigger tires, etc)? Maybe a lightly dragging parking brake? Lots of possible factors…

 

What rpm’s do you keep at or under for acceleration?
What about at 65 mph?
I would love any detailing of the process.

 

I am too but with my 6500 lb travel trailer in tow, it's more like 10 mpg.

 

Seems to do best under 2k RPM.

 

Both stock trucks. Not the same though, the 2018 was a Double Cab and the 2021 is a CrewMax. So yes, the 2021 is heavier, but I don't think that accounts for all the difference.

My 2021 with tow/haul engaged feels like my 2018 with tow/haul disengaged.

Here's both the day I bought my 2021:

 

Definitely because of the trans cooler.

 

Whatever the difference, I don’t think it’s something inherent with the ‘21 that makes it worse. On Fuelly, the 21s’ average is 0.3mpg higher than the ‘18s.

 

Early on I did assume it was just some quirk of my particular truck, but then I did at some point have a couple people on this forum echo my observations. Who knows.

 

I have been taking weekly trips with my '18 Tundra to the cabin.
I have been hauling up fire wood logs, tools, other stuff (always loaded) in hilly terrain and find although it may take a bit more gas to get going, once rolling it goes better longer without touching the gas, and stopping obviously will take more effort.
Stock 2018 truck outside of the Borla exhaust and tonneau cover. I had the AC on and I got 12.0 Liters/100 - 20 mpg.
Very happy.
All it takes is a little happy foot to drop that mileage to 15 but it sounds so good doing it.
I can see getting 22 mpg if it was flatter.