How to improve gas mileage

I just drove from central Washington to Boise Idaho, around 400 miles. 2014 CM 4x4 5.7 with 2 adults, 2 kids and some luggage. Speed limited on the way down are mostly in the 60-70 range, in Idaho it jumps up to 80 for a short time. Cruise and A/C on for a majority of the trip and I got 17.2mpg. Last time I checked this I drove from central Washington to Spokane,WA which is 90% 70mph highway by myself and got 15.9mpg. Only difference was time of year. After a few trips I quit paying attention because whether I get 14mpg or 17mpg it’s still shitty gas mileage.

 

Learning to time the injector-off coasts when there's no traffic is a big boost to mpg. At that point you're riding in a 6000 lb kinetic battery that you paid to charge up, so might as well not throw it into braking heat unless necessary. From 55 mph the truck can roll using zero fuel with engine braking well over 1/8 mile.

Steady foot is king. The computer's solution for everything is 'add fuel,' even for little actions. You know how you can push the pedal so hard to keep a speed, and you decide to push it a tiny little bit more to gradually speed up. Wrong thing to do. Take the mpg you were getting and divide it by 2. Better to push hard enough to not quite downshift and get it over with. Some drivers are really bad at this. They'll gradually accelerate, notice they're going to fast, totally let off until they're slowed back down, and then gradually accelerate again. Repeat over and over again and wonder how a stock truck can get 10 mpg. Heck even touching the throttle on a coast down for just a split second will usually cancel the open loop injector shutoff for the whole rest of the time you're slowing down. It has so many excuses for adding fuel.

It seems counterintuitive but if the accelerator is held so the truck shifts at or just above 2000 rpm, it will tend to set the actual throttle at 65-70% engine load with the converter unlocked and 75-85% after lockup. I wonder if someone calculated heat losses due to converter slip and that's why the engine load is lower than expected there. Anyways it does seem more efficient as annoying as it is to accelerate that gradually. So far I'm still getting just barely under EPA's gasoline numbers with E85. The really stupid thing is that it needs the ethanol to drive like that. My motor carbons up so badly on gasoline if I drive for mpg that by the time the pinging takes all the timing away there's no point. E85 is always doing a metric ninja lizard butt ton of steam cleaning no matter how hard it's driven plus its 100ish octane so it always runs with max timing.

The most efficient speed on stock gearing and tires is without a doubt around 45 mph. Get a flat road without stops, set the cruise at 45 in 6th gear, and the truck would average an easy 25 mpg on gasoline. Good luck fending off the road ragers tho.

Why waste time adjusting the nut between the seat and steering wheel? Someone said $10 gas, so I'm gonna start practice early

 

I drive mostly city and get an average of 14.6 mpg. I guess that’s good and only need to fill up every 3 weeks so I am ok with that. I didn’t care about good gas mileage in getting me a full size truck. If I wanted that I would have tried for an unreliable Chevy Silverado with the BS Active fuel management and watch my truck from afar in the shop for excess oil consumption issues and worn cylinder heads. A mechanic told me to stay clear of them and the Ford eco boost engines.

 

I work with quite a few GM guys and it was surprising how many were talking about trading in when they heard the 5.3L trucks doesn't have cylinder deactivation right now due to supplier issues

 

If it will make you feel any better, i only get 10 with mostly highway miles. Avoid the supercharger or have a gas sipper for you daily drives.

 

My lifted tundra gets less than 14 mpg idling in the driveway. I never got above 15 even when stock. I get 11 now with 6” and 35’s. Wouldn’t trade it for any other truck

 

That doesn't surprise me at all. For some reason there are a ton of GM fanboys where I work; and *literally* the first thing ALL of them did when they bought new trucks was to disable the AFM.

 

By definition, every vehicle gets 0 mpg idling in the driveway...

 

The Mobil 1 75w-90 came out of the rear pumpkin today and Redline 75w-85 went in. My little 255/70R18 Michelin tires up to 38 rear 40 front. Time to get serious about it and see what's possible. If I can get a Fit rated 28/34 from Grand Rapids to Mackinaw City and back again on a single 10 gallon tank, I should be able to crack this coconut

 

Ive used S mode this week. For my truck, driving style, and routine commuting, I can’t say that I have seen an improvement in mpg, and I have used about half the tank. I’m currently running 14.8. I finished the last tank at 15.2.

It is by no means worse, but not noticeably better for me.

 

Despite an awful headwind/crosswind gusting over 40 on the return trip, I squeezed out 15.3 mpg hand calculated with E85 today, filling twice at the same pump for accuracy. This was the 3rd consecutive tank of E85 so the alcohol percentage has to be getting up there. Stuck to the speed limit, no cruise control, kept off the freeway as much as possible, mostly kept it under 2000 rpm on upshifts, just basic conservative driving. Zero 'drafting' tricks, no funky shifting, just drove in 'D', and I never roll a stop sign. Another way to put it, that's 204 miles for $26 in fuel in our favorite 6000 lb 4x4, beating the 11 mpg E85 EPA highway estimate by 39%. So it is possible to coax more out of this lead weight as long as you don't bribe the engine with the money pedal. And FFS the cruise control hogs the most fuel out of anything unless the road is perfectly flat.

I wonder how far I could go on ethanol free gasoline

 

So I just did a drive from Lemoore, CA to Moreno Valley, CA. I make this trip routinely, so I do know that I can complete this trip alone on a single tank. After the lift and wheels, I noticed the following.

6" lift and 33" tires, 12.5 wide was recently done, and I performed the same drive with my family. This time, I made the same trip albeit with my family, wife and 3 kids. I made it to HWY 60 before having to fill up. After the lift and wheels, I can confidently say I've lost a little gas mileage, but MAYBE 2-3 mpg less... so nothing too extreme. I did not have to recalibrate the speedo. Accurate up until 90 mph, and then it's like... shows 93 when I'm going 95. I lost a bit of turn radius, and I need more room to brake. I'm overall pleased with the transition to a lifted truck.

This is a truck that teaches you throttling and gas saving... I swear thats what this truck was made for.

 

At least you can add 3% to your odometer miles to calculate mileage with the bigger tires, provided it was accurate enough from the factory. Some are off. My Tacoma was super bad. Naughty engineers. They wanted to use the same everything on the 5 lug and 6 lug trucks. The odometer was high 4%, the speedometer 10%. Took me a couple weeks to figure out why I was so often tailgated. A speedo gear change fixed the odo/trip and I just used the ultragauge for an accurate speedo.

The weird metric version of mileage makes it a lot easier to visualize mileage differences as a cost difference. They do liters/100km. It's easy to make an English version, just do 100/mpg and that makes gal/100mi.

You hear 'only a couple mpg' without context a lot but the bigger the hog, the bigger the drink. For a Yaris getting 40 mpg (2.5 gal per 100 miles) losing 2 mpg isn't much (2.63 gal per 100 mi, or $0.39 more per 100 mi @ $3 gas). For a Tundra, going from 16 mpg (6.25 gal per 100 mi) to 14 mpg (7.14 gal per 100 mi, or $2.67 more per 100 mi, 14% more) is a lot bigger. Then tow a trailer at 8 mpg (12.5 gal per 100 mi) and wonder how Toyota engineered a black hole into such a small tank haha. That's also how for a tractor trailer driver a tenth of a mpg can mean thousands in savings.

 

Best mileage I ever got I filled up at the last mountain peak east of San Diego then drove to San Diego, over 40 mpg

 

Gravity makes us either hybrid-status or war ship-efficient...

 

You can't!

 

I was getting 17mpg on the highway. Did 3/2 lift, 35" tires. now getting 13mpg.

 

The other aspect greatly overlooked with the Tundra and gas mileage…is that you simply can’t let these things idle. I never let mine idle because it destroys the mpg’s for the entire tank. Idling in traffic is one thing but if you can shut it off, do so.

 

I shut my truck off when waiting for trains...idling is the number 1 killer of mpg of the Fundra...I refuse to get an autostart for this exact reason...I'd get 100 miles a tank if I used autostart...I have a tiny lift up front and heavy 33s...all in and it being winter months, 12mpg is average and in summer I'm at maybe 14mpg...but it always starts and doesn't break down...worth the fuel cost to not be left stranded. My buddies F150 is stuck at my house for new turbos again...only 5 turbos swapped on his truck, but he is at 170k miles...still,not something I need or want to deal with...

 

Buy a car.Dont want to sound mean but I knew mpg sucked when I bought it.Nothing is going to help except for keeping foot out of it and that's not going to help much

 

Buy a prius, your in the wrong forum.

 

that actually makes a lot of sense, I've always noticed the truck gets better mileage just after filling up (heavy tank = better mpg) the thought didn't occur to me to add weight in the bed to continue weighing it down when the tank got light

 

here are a couple things I found that have actually helped my second gen

firstly: pedal commander put in eco- mode (yes, it sucks, feels like driving like a grandma, but it keeps your foot light- noticed 20% increase)
secondly: (after getting rid of the pedal commander- I was just trying it out, will probably get another one eventually) cold air intake and exhaust, I noticed a good 2 mpg around the city and 2 mpg highway (increase for both) so from 10/12 to 12/14 (more consistent on the highway at 14 than it was in the city at 12)
thirdly: new gas pedal, second gen pedals are very sensitive, getting the pedal replacement from sparks parts helped out a TON, I had kind of gone back down to 10-11 mpg city and the newer pedal pushed me back to a consistent 12 (I figure the less jumpiness meant less gas burned)

this was all on 33" tires, but now I'm on 35" and the mpg is a consistent 10/12 (no re-gear), definitely sucks but my truck has never been the golden child for mpg (2007 RCLB 4.7L V8 - 5 speed tranny)

 

^^THIS^^...KEEP IT STOCK

 

https://ecomodder.com/forum/fuel-economy-mpg-modifications.php

https://ecomodder.com/forum/EM-hypermiling-driving-tips-ecodriving.php

 

Just curious if recalibrating the speedometer is a relatively simple task?

 

Generally you need an additional device to reprogram it. Correcting the speedo will keep the odometer accurate as well.

https://youtu.be/IoLI96FdYEo

 

Ahh, ok. I did something similar on my previous truck (F150). Was hoping it would be easier for the Tundra without having to buy stuff. Oh well.

 

I should also add that your speedo can be off from the factory. I lucked out that mine was slightly off, so going up to a larger tire (275/70R18) wound up putting me very close to dead on for speed.