This seems really low, what do you all think? (yet another mpg thread)

2nd owner 2014 1794 4x4, just hit 78k miles.

A few weeks ago, I added 275/65/20 Falken Wildpeak AT3/W tires all around, E load.

I have Bilstein 5100's on top setting plus shims for 3" front lift, SPC UCA's, and diff drop.
CB+3 shackles in the rear with 5160 remote resi shocks, and carrier bearing drop.
TRD exhaust and rear swaybar.
Amp powersteps.
Window vent visors.
Cheap soft cover tigre or something.
No other mods that would affect fuel, stock engine.

My truck has had low mpg since I bought it used stock (except trd exhaust and rear swaybar), as the 2nd owner with 53k miles Feb 2020.
Started at 14mpg city, and 16mpg hwy with stock brand new tires.

Lift took me down to 11.5 city mpg and 14 hwy mpg.

It is fairly hilly where I live.
After the new tires around town I am only getting 8-9.2mpg, and this is with keeping it around 2k rpm driving like a scared old lady.
Hwy driving at 60-65mph mostly flat I got almost 14 mpg in testing.
Yes, it is winter here and it sucks.

I have no check engine lights, nothing seems wrong, alignment is very close but drives side tie rod is now frozen (tried to align after tires) The tech cooked that side with a torch and now my Power Steering boot is ripped on the end from the heat and slid inside towards the motor

Truck has always seemed to have a very slight vibration at idle since I got it.
I already replaced the plugs and cleaned the maf like 6 months ago.
I also have bad timing chain guide knock on the drivers side on cold starts but goes away eventually after warm and while at speed.
I know eventually I will have to get this replaced but I hate cracking open a stock motor that should go 500k miles np otherwise, plus the huge cost for this repair.

Am I getting what everyone would consider normal mpg for my setup?
I used to drive heavy foot before the tires, now I can watch the gas gauge drop on my 26 gallon tank and I'm like "what TF have I done!"

I feel like something is wrong when I see/hear some of you getting 13mpg+ on 35's.
I don't even have 35's wtf.

Please tell me your thoughts I am

 

Sounds about right. Cold temps plus winter fuel doesn’t help the fuel consumption. Anybody with 35s and says they “average” over 13 mpgs is lying lol

 

You are in VA and we have had some pretty cold weather. That drops MPG easily by 1 to 2 MPG. If you idle at all to warm the truck, remove ice....count on another 1-2 MPG drop.

And those drops are for the TANK average! I get around 13 city generally. Just got gas last night, checked the MPG, hand caluclated and I was at 10. Never been that low before but we have have snow, ice, did a good amount if idling and running around in 4wd during the bad weather.

Idling KILLS MPG more than anything in a Tundra.

 

Thanks for telling me you think it's normal.

I often wonder if those 35's folks are lying or wrong....
Or if something sneaky is wrong with my truck...because that's what it feels like.

Yes it's cold, winter atm, but these mileage records are from fuelly and since I bought the truck covering all seasons, they haven't really changed even in different seasons.

I am confused and seriously regretting these E load tires now.

Thanks for your thoughts.

 

Thank you for the feedback.

This is consistent since I got the truck, all seasons, barely any change seasonally, and from fuelly.
I have logged every drop of gas since I bought the truck.

My dte these days is like 240-260 lmao.

I pray something changes when warm weather returns. If not I might have to sell these tires at a loss and rethink my lift even.
If I were to tow anything significant right now I'd be like 4mpg.

That just doesn't make any sense bassed on so many other posts I have read here for years.

 

I have been wanting to ask this.

Does anyone have any data on how rake effects mpg?
I searched and found nothing.

I was considering lifting my rear more to get back to factory rake to see if that helps mpg noticeably.....

Anything on the motor I should look into besides maf and plugs? It runs and seems fine other than the timing chain and I can't see that causing this. Maybe it is?

I've run 0w20 oil and 5w30 oil no changes.
Lucas Fuel system cleaners.
Wheels do not seem to be binding in any way, they spin fine by hand.
No growling bearings that I can tell.
Drives straight, doesn't pull or wander, steering wheel recenters when released.

Front brake pad wear indicator starting chirping a few weeks ago so I got OEM rotors and pads from local dealer, along with 1.25 sprdertrax spacers x4 to put on asap once it warms up (no garage here). These tires though stock width are super close to the SPC UCA balls and my passenger side rubs the front swaybar at full left turn.
Front mud flaps gone no other mods needed to clear.

 

Sounds normal to me also. The heavy tires and lift make a big difference.

 

are you going off of computer or hand calculating? Are you adding back the difference in tire size? That makes a difference and you should. I run 33s, so my current tires are 3.4 to 4% larger than the stock 32s. Use your miles for the tank, lets say you got gas at 200 miles in. Don't use the 200 miles for your calculation unless you run stock 32inch tires. Add (not sure how tall your tires are), lets say they are 4% bigger, so 33.3 tall. You need to add that 4% to that 200 miles because you actually traveled farther with large tires vs the stockers. So use that adjusted miles, and then the gallons for the fillup for your MPG calculation. This effect grows as the tires get larger than stock. If you are not doing that, you are actually getting better MPG than you think. Make sense?

Dirty air filter and MAF will impact MPG, so you may need to replace and clean those. You should not need spark plugs yet with your miles. Adding heavier oil in the diffs will drop MPG too.

 

Lifting it and putting on bigger tires is going to take it's toll. Doesn't sound terribly out of line. I'm on smaller tires, a smaller lift, and I have stupid good luck with MPGs (only good luck I have) and I was averaging about 15. Hand calculated until able to confirm the computer is running accurate to within 0.1-0.3 MPG.

 

Thank you for the feedback.

Maybe this is just normal after all.

 

This is from the truck, and fuelly.

I have not done any hand calculations after the tires.
But I can literally see the gas gauge go down, and I could not before them, so it's definitely gotten worse lol.

I use this site for tire sizes. Of course, there is some slight variation from manufacture/model of tire also.
Diameter increase by 6.9%
Width same
Sidewall increase by 16.7%
Revs/mile stock 632, new tire 592
Speedometer used to read 2-3 mph higher than google maps gps shows at all speeds.
Now it's almost dead on, or slightly low on the gauge by 1mph at most.
Meaning stock tire I was going slower than the speedometer said.
Now I am going dead on according to the speedometer, or I am almost 1mph faster than the gauge says.
All based on comparing to google maps gps read out, consistently since I got the truck.

Maf, airfilter both like new.
I did spark plugs last year after lift hoping to find an issue, plugs all looked good but put in new one's hand gaped anyway.

Thank you for reminding me about the tire size difference!
I will try to do the hand calc on the next tank (need the formula), just filled up yesterday but it will take a while as I work from home and it's too cold to go anywhere lol.
I really don't expect to get much back here, maybe a little.....

As I said, I can now see the fuel gauge drop unlike before, even driving like crazy gently.

Guess maybe this is the "new normal" lol.

Are smaller wheels, and bigger tires, lighter than larger wheels and tires?
I like my stock 20's but maybe I should go to 18's and the tires/sizes I like.
Will that be significantly less rotating mass, and less mpg loss?

Maybe tiny changes here and there will get me back where I don't feel like an idiot anymore for doing the lift and tires?

My concern is the range, and cost, 8mpg vs 14+ mpg is significant loss imho.

My summer trips to OBX/Hatteras/Ocracoke Island at 8mpg or less loaded with gear is going to come close to the cost of the hotel at this rate.
That is not cool.

 

Thank you for sharing.

I would dance a jig at 15mpg lol!
You are VERY lucky indeed.

My 8mpg just seems REALLY low for my 3" lift and 34" E tires.

My father previously had a 2014 1794 and his mpg were way better than mine.
He drives real smoothly, but was getting 16 city and 18/19 hwy, even after wheels and 33's (no lift).
My truck has been lower than that since stock/new to me.
Even when I drove like he does.

Between my mpg and timing chain issue, I feel very unlucky.

But I LOVE my V8 Tundra!

 

Tire tread patterns, tire weight and undercarriage turbulence will all degrade MPGs. Keeping up with 95 traffic is also a contributor, 55 to 65 MPH is the sweet spot.

 

I have a 2014 1794 4x4 as well.

I have a 3 inch front and1.5" rear lift. 37" tires. In the summer, I average 12 mpg. Winter is about 10 mpg. These mpg reading are from calculating fillups and mileage (not from the computer). My $0.02...

 

My tires are about 34.5”. My truck usually settles around 11 mpg. I mostly drive 55 mph roads and some in town stop and go. Due to the tire size difference, I think it’s actually about 1 mpg higher. Driving only highways, the truck will say 14-15 mpg.

 

Indeed. All known and I agree.

Thank you for the feedback.

 

Thank you for sharing!

This is a really good comparison.

See, I am below that, even keeping the engine under 2k rpm.

Is it really flat where you live/drive?
Do you drive mostly Hwy?
Maybe vehicles vary that much one to another?

You have presumably E rates tires that are heavier than mine, maybe even wider?
About the same lift.
Are your 37's on 20in wheels or smaller?

I am thinking smaller wheels is the way to get some mpg back.

I need to research if smaller wheels with the same approx tire size is less overall weight, and how much, to see if it's worth it and will return any significant mpg.
Even though I hate small wheels.

It is also very hilly right around my neighborhood, then mostly flat around town. So I have that going against me.

I just can't shake the feeling something is off with my rig.
I feel like I should be around 11-12mpg city, not single digits.

Such a head scratcher.

Thanks everyone!

 

I have stock offroad wheels, no lift, RCI skids, a Harrop blower, and about 500lbs of gear I haul. I'm getting similar numbers especially with city stop and go. You can try a throttle controller or an air dam (only needs to be as low as your lowest point). A smoother undertray can help too just don't choke the cats. Beside that not much else to do but adjust driving behavior (play the game of coast).

 

Thank you for this good feedback.

Even you are getting significantly better mpg then I am. With bigger tires.

Yes it is hilly and slower speeds normally for me. (just within half mile of my neighborhood)

But 3mpg difference?

We are about the same Hwy from my last test.

Still need to do hand Calc with tire size considerations to get more accuracy.

I don't expect that will gain me more than maybe 1mpg, still puts me in single digits. But we will see.

Thanks,

 

You have much more weight than me it sounds like.
What tires?

I have heard supercharger can eat more gas, or save gas if your gentle.

I'm surprised your seeing the same mpg as me with what you described. That seems off, but you have that extra 500+lbs.

What happens when I add 500+ lbs of gear to my 8mpg lol.

I feel like the only thing I can tow now is a fuel trailer lol.

Good thing I don't have anything to tow, just 200lbs or so of pdl fishing kayak in the bed with an extension and all the gear in the backseat.

 

https://www.michelinman.com/auto/tires/michelin-ltx-a-t2

I was seeing about 14.5 on my commute 60 HWY/40 City where HWY speed is about 80MPH. Pure City driving I've seen high 8s to mid 11s. Depends on conditions. Winter blend has been worse for sure.

 

I’m in a mountain town but I don’t drive big grades everyday. 80% of my driving is around town, not highway.

My 37s are on 18” wheels.

I do feel like getting single digits in MPG is weird. Not sure…my truck isn’t a flex fuel model, is yours? Don’t think that should matter tho

 

So you are at higher altitude, but not going up a down a lot of hills.

My overall elevation is closer to sea level give or take.
My hills are just within about 1/2 mile to 1 mile of my neighborhood, and most only in 1 direction, whereas the other direction into town, its fairly flat compared to right by my house.

I would say for 37's single digits doesn't seem unusual.

Those tires, even on 18" wheels have to weigh a ton.
I have factory 20"s, they are not light, and my new tires I think weigh around 76lbs each.
I heard factory 20's are around 41lbs.
So, it seems like my tire/wheel combo is around 117-120lbs each.

I need to get exact weights.

Then compare some 18's and similar size tires and see what those come out to.

I'm sure the key to some better mpg is less rotating mass on the hubs.

I bet light wheels are very expensive though, and small.

My truck is not flex fuel.
I would not touch that crap with a 10ft pole.
Ethanol fuel is garbage science.
Using food for poor energy content fuel that gums up most systems, hard pass.
I have read some have issues with their ethanol sensor and ECU causing really low mpg, wish my mystery was that simple lol.

I think I will plan my next tires to be on smaller lighter wheels, pending cost, when it's time to replace these.
Now if manufactures would just make 34-35" tires with a steel belt/load rating between passenger and E.
I love the puncture and heat resistance of E tires, hate the weight.
Why can't we have 5ply or 6 ply tires in every size.
10ply is way overkill, and 2/3 ply is way too little for a truck.

Still wondering if something is off in my engine though......

 

Pretty much most older V8 engines always got around 12mpg average when actually used as a truck not just some drive around vehicle. I’d imagine it’s not hard to see sub 10s with modifications.

 

Yeah, what you're seeing is the worst of it, I'm thinking.

- 'winter blend' gas - my own truck has gone from 17MPG to 15MPG
- Falken Wildpeak tires - those ALONE will knock 1MPG or so off. They did the same thing with my '13 F150 and my wife's '12 Highlander.
- Lift - affects MPG as well

Not that this helps, but other vehicles are much the same. My friend's '17 Silverado, bone stock, gets 17.5MPG Hwy, 15.5 or so MPG City. A bit better than mine, but only just a bit....and he loses a quart or so of oil between oil changes. They just make a bigger deal of it w/the Tundra because it's a heavier truck, because the 5.7L doesn't have anywhere near the 'gas saving' features that others do (e.g., cylinder deactivation, etc.) Frankly, that's why I bought mine. MPG is definitely a mile or two per gallon worse, but at the cost of....far better reliability.

 

Lifting the front kills aerodynamics and definitely hurts mpg on the highway. Shouldn’t alone affect city. Fixing rake probably wont help much, as the height below the truck was still increased. Anything taller has more resistance period. Just my guess, im not an airflow engineer, but my mpg took a hit with a lift and stock tires.

going to 18s with the same tire diameter probably won’t do anything. I went from an E rated tire to a P rated tire of the exact same size, yet a ton lighter. Zero affect on mpg, i was very surprised. Not saying weight doesn’t hurt, but diameter has way more effect than weight. I used to run 35s, i got 16mpg at 65. Stock tires i get 19-20 at 65.

 

Ya’ll should try dropping a 5.7 in a 23’ boat and then your tundra mileage will feel like a corolla.

 

+1, V8s suck gas when idling. I have watched MPGs drop by 1 or more in heavy traffic. Cold weather and short trips will lower it also. My winter MPGs are usually lower by 2 in cold weather. Have you taken in to account the larger diameter tires?

 

Agreed all around.

The lift hurt my already below average mpg.
Then heavier tires made it worse.

Winter temps and bs winter fuel made it even worse.

Toyota beat domestics hands down, especially in longevity and maintenance, no debate there.

I just feel my mpg is lower than it should be for my setup, and has always been below average even when stock.