Stomping it for better mileage?

Ummmm......no. WOT may burn some off at times if it gets built up but using a high quality fuel with proper additives will keep it from building up in the first place. But I agree, more carbon=less MPG over the long haul

 

Here is what I have found with my 2010 CM 5.7 S/C 2wd Tundra. I get my best MPG right at 2000rpm or just a hair under. If I am on the highway doing over 70mph the truck has the aerodynamics of a flat barn door pushing against the wind and the MPH goes down. If on a 55mph road I use the manual shift to keep it in 5th so the RPMs stay right at 2000. If the overdrive (6th gear) kicks in at 55 or less then it drags the engine and the MPG goes down. 2000RPM seems to be the sweet spot for the 5.7

 

40¢is more typical here too. I just happened to notice the $1.00 upcharge on Saturday. Since I quit running a modded Mercury Black Max with 140 lbs of compression I normally dont pay any attention to the price of premium. For the most part I run ethanol free in my current boat and around here it only comes in regular. I did the same experiment in my Tacoma. The only time I saw any gain was towing my 5000 lb Bay Boat.

 

Yeah, the use of high quality fuel and proper additives are assumed unless otherwise stated.

 

Carbon build up is a thing of the past. Modern computerized vehicles burn much leaner and cleaner leaving little carbon behind. I remember when I had my 1987 F150 351 HO with a Holley double pumper. I would open it up now and then after getting nice and warmed up and would get a puff of black smoke out of the tailpipe.

 

Absolutely.
Wind not so much an issue here in SC but if I go TO Charleston, I get better mileage than coming back, why? I'm climbing up hill coming back. Granted, we're only about 600 above sea level here but it makes a difference.

 

I second this.. it’s because the stupid cruise control doesn’t want to do anything but down shift every time you go on a slight incline. The Dallas North Tollway wreaks havoc on the tundra cruise control.

I also get better mileage driving around town than I do cruising at 80 on the highway. I just did a quick trip up to OK and back, cruise set between 70-77 the whole way there and back and I averaged around 14.7MPG wtf.

 

No way you're getting that mileage at those speeds. Did you reset the computer for each trip back and forth? The computer bases its calculations on total mileage since you last reset it. So if you drove 10,000 miles at 70mph and averaged 20+ and then did a trip at 90mph it's probably going to have little effect.

At 80 you're lucky to get 16's on a 4x4 Crewmax. 85+ you'll be at 15-14.

I could barely get my computer to read 18mpg cruising at 72mph for a few hours.

 

I think I do slightly better because I put it in sequential mode. So while in cruise control, I am ahead of the truck downshifting and put it in the proper gear. Sometimes just taking over completely.

 

Notice they are nearly full tanks.

 

Crewmax 4x4 lifted. I don’t reset my average until I’m taking a long long road trip. That’s my average driving back and forth from Colorado Springs to Denver and back. My normal speed is 75-80 it’s 1.5 + hours of driving each way. 85 octane 10% eth. I’ve even done the math and got mpgs from miles driven vs gallons used. When I go to Breckenridge once a week for skiing it’s even better than 20. It’s 22-25 (25 if I reset)

 

I wonder if the higher elevations have something to do with it?

 

I drive a good combo of interstate and city and stay around 16-17 mpg. Just to be a geek, I've been experimenting with cruise control and haven't noticed any difference. Of course I didn't buy this truck for gas mileage, but it's fun to try and learn it's nuances.

 

My 2019 with 10k on it is getting 18+mpg at 80 on flat interstate no wind. I got 13.7 yesterday pulling a 3000lb trailer at 80. I am very satisfied with the mileage my Tundra is getting. Overall its averaging better than my 2007 gmc sierra doing the same duty. And it does the towing much better than the GMC.

 

Yea 5.7 I’ve put a volant intake on it since I got it. Changed all fluids to amsoil (except the tcase) and it’s legit what I get. I don’t put out accel from a stop. Just a normal accel to get to high gear and then just hold light throttle. If I see a redlight I’m off the gas and coast majority of the time. Maybe it’s the high altitude because living in Oklahoma (using 100% gasoline) I’d only get to 19mpgs max average. When my wife drives it drops down. I don’t have a program on it. I run 49 psi on 33” bfgs don’t need max ac out here in Colorado either. And yes trans filled with amsoil and also was flushed at 45k with amsoil fuel system cleaner every 10k. I change my oil at 10-12k miles (once a year or the mileage) and I’ve done a full fuel system clean at 45k also (where the engine runs off purely the fuel cleaning concoction lol)

 

It's got to do with specific fuel consumption. Hypermilers work around that principle to get the numbers they do. It's basically a ratio of power output to the fuel consumption rate. Most gas engines tend to have the best SFC somewhere between 1500-2500 rpm at the highest throttle that doesn't bring the engine out of stoichiometric burn. The more power per gasoline, the less fuel used, as the end kinetic energy in the truck is the same.

A weird one was the 1st gen Honda Insight. IIRC its best SFC was 90% throttle at 4500 rpm.

A real-world application that hypermilers do is pulse and glide. I.e. at max target speed, kill engine and coast in neutral, slowing to a min target speed, start engine, and run high load to max speed and shut off, so on and so forth. Eliminate the low-load inefficiencies. That's how you get 150+ mpg out of a 1L engine.

When you think about it, it kinda makes sense. When under partial vacuum a part-throttle gas engine makes lower effective compression than at full throttle, and compression is super important to get the combusting gases to transfer their energy into a piston during a power stroke.

The Tundra's programming is terrible for mpg purposes but good for driver enjoyment and towing. It will keep load in the 60s to low 70s % most of the time when accelerating. It upshifts when it drops to 65%. Lots of reserve throttle and feels sprightly. Efficient would be 80%-90% while keeping it below 2500 rpm, but pinging could be a problem on 87. Also people would think the truck feels 'doggy' because it needs a lot of throttle to get moving and still upshifts aggressively.

 

Not sure I get what you're saying about compression as that is determined by the open area of the combustion chamber at TDC determined by piston clearance to the head and the volume of the chamber at BDC. I do wonder about the thermodynamics of the engine off and not running accessories during this phase as is cooling system for the engine is basically off along with the AC.

I remember doing stupid stuff when I was a kid by putting a couple of dollars worth of gas and turning off the AC to stretch the ride and putting in neutral and coasting down hill because it was an oh shit moment.

 

Wait, there is another option besides Beast Mode to drive in?

 

22-25mpg running 75-80mph with a lift? lol

You sir, have the most fuel efficient Tundra on the planet.

 

Read it please. 22-25 is going to Breckenridge Colorado. Which is in no wear near running 75-80 mph. 80 mph my truck has been getting 20 mpg’s. Going to breck I might hit 70mph on a long stretch of road that isn’t twisty. Otherwise it’s 55-65 with a lot of sections doing 30-40. Hence why I specifically said going to Breckenridge and back I get 22-25 mpg’s. If you are always above 3k+ rpms then you shouldn’t expect high gas mileage....

 

Today

 

I’d agree. I get pretty good average mileage in my Tundra and find that using very little throttle to accelerate very slowly results in worse economy than if I nudge the throttle (Not WOT, that burns gas and tires, MAYBE 1/4 throttle) and accelerate moderately fast, then cruise at a constant speed.

 

You guys are all kicking my ass.

CrewMax 4WD No lift, stock tires, engine 5.7 with tow package. 33k

15.5 mixed traffic, 70-73 mph on highway. No jackrabbit takeoffs
Almost exclusively COSTCO regular.

Wish I knew the secret.. Lol

 

ALWAYS use PREMIUM !!

More MPG & less water out of tail pipe !!

Take 3 clear glasses and fill each one with the 3 different octanes and tell me which one you want your motor to DRINK !!

JM2C

 

I'm confused. I've never seen a difference.
I have seen ethanol vs non ethanol.
Always thought water was a byproduct of combustion, normally steam unless exhaust system is cold.

 

I pump faster, so that I last longer

 

This is what I did at last oil change and maybe the tonneau cover helps with drag. If it doesn’t still it’s fuckin awesome.

 

It's TRUE, driving like an old man isn't optimal. It leads to lugging, lugging is bad.

Get beer, read, believe.

 

What color is it?

 

The biggest killer of fuel mileage is the brake pedal. Drive so you don’t touch it, and your numbers will improve. Or you’ll get tickets.