Tire Pressure and MPG

Hi All,
Curious as to what air pressure you're running in your tires and what you're getting for mpg.

I was getting real bad gas mileage then realized my tire pressure was around 30psi. "No wonder" I thought. However, I still think my mpg stinks.

I'm currently running 33/34 psi in my tires. I've got the stock 265/70/16. Driving around town, I'm getting 13.5 to 15.5. On the hwy at 75mph, I get 17 to 18ish. But, if I cruise around at 30 to 50mph I can get low to mid 20s. I'm also in a manual which supposedly gets worse mpg than an auto.

 

I've never run truck tires anywhere near 30psi. It's not your tires. You drive a brick. To get good mpg on a brick you drive in as high a gear as slow as possible with as little braking as possible. Your mpgs sound normal

 

Sounds pretty good to me, my 2nd gen same setup does a bit better in town but it drops off a cliff over 70. Sweet spot for fuel mileage on mine is 40-60 it will get 19-21.

Tirre pressure may make a marginal difference if your running standard P rated tires, if your running LT tires you may want to run closer to 40-45.

 

32 psi 4.0 w/Auto
MPG was 19ish about 10 years ago.
Now it's $40/$50 at a time.

 

This is exactly the mileage my 23 OR gets, thanks for confirming. If I do any town driving mixed with highway, it is 12.5-14.0. I have only broken 20 MPG twice over the first 9k mi.

Tires are 32 PSI at 70F.

 

32 PSI on the original Firestones on my 2020 TRD Sport. Average is 22 to 23 combined with the 6-speed manual and +/- 42,500 miles on the engine. I typically drive 2 to 3 MPH under the posted speed limit. I've gotten as high as 27 on a total highway run.

 

I’m around 32 psi on 285/70/17 tires and aftermarket wheels. Heavier build with aluminum front bumper, full skids, and winch.

My average mileage is 16 mpg and best tank is 19.

 

Thanks for the replies everyone. I guess it sounds like I'm doing most things right and this is just what the mpg is on this vehicle.
Happy Thursday All!

 

I average over 20, but with the 245 size tires. My driving is 40-50 mph, very few stops, and at 6000’ or higher.

 

Lower speed really makes a differenc

Speed really matters. If I drive 65 and like there is an egg on the pedal I can keep it over 20 MPG. I get a consistent 14.5 MPG on the highway with radar cruise set at 85 MPH. Driving style is everything for mileage.

 

I wouldn’t say “normal”

I easily get better MPGs than that on my lifted truck running 33s and constant weight. My PSI is at 40 front and 37 rear.

 

Running 34 psi on bfg trail terrains stock tire size … off road 6spd manual . get around 17-19 city
Highway 21-24
Using shell 87 gas

 

you've only accounted for discussing one of at least six variables in this mpg question. but everything is a balance.

1. tire pressure
2. driving style
3. tire width/size/tread/compound
4. desired tire longevity/vehicle control
5. onboard weight
6. gear selection

tire pressure plays a small role in mpg. generally the higher the pressure, the better the mpg, as it will turn a flat-bottomed tire into a more rounded tire, where less of the tire makes contact with the ground. less contact means less friction. but that friction is required for stopping, especially panic stopping.

jumping away at every stop light like you're life depends on it uses extra gas. but sometimes your life does depend on it. ideally, you're grabbing the next gear as soon as it's feasible. keeping the truck below 2,500 rpm at all times will offer the best mpg gains.

running a street tire over an all-terrain or mud tire, will result in better mpg. but perform worse off-road. at the same time, a narrower tire will offer less road friction, which can improve mileage. and then there's the compound. rubber isn't just rubber. there's tons of 'eco' tires that aim to reduce friction within the compound of the tire, and plenty of performance versions that seek to increase it. each has their own special uses. typically 'eco' tires cannot work in cold temperatures, requiring another set of dedicated cold-weather tires, which will use more gas while in use, and cost extra in setup and storage costs. but performance tires generally seek to make for ultimate traction, which means the most friction, and the best stopping ability, but the worst mpg.

while all of this conversation is great, most of us generally don't have limitless tire budgets, and also generally care if we can stop in time for the kid running across the street, at the very least, to avoid being lambasted by the evening news. so the core of this thread, tire pressure, plays a significant part in the vehicle dynamics, but also the tire tread lifespan. tires perform equally best in all categories when the pressure is optimized for the tread to make equal contact across the entire tread surface of the tire. but adjustments can be made in either direction to increase one aspect like boosting pressures to reduce the contact patch, at the cost of increased tire wear/replacement, and reduced stopping or turning performance.

the weight one is carrying around all the time also plays a part in mpg. leave grandma and the roof top tent at home. she won't remember where you were going anyways. at least that way you can save a little gas to go there.

and lastly, there's the gear selection. i've found the automatic programming to be overly-conservative. great when i'm trying to save gas, horrible when i just want to bounce off the rev limiter and GO. with the manual, you've got a slight advantage here, to be able to pick your own gear. but if you're not in 3rd by the time you get to 20mph, you're likely leaving some 'wasted' mpg's on the table. it means lots of early and fast but smooth gear changes.

of course, there's also things like proper vehicle maintenance as well-- running around on worn ball joints, a bad alignment, or old oil will easily eat into mpg's.


there, that's my five cents of friday thread contribution. 2 cents that i wanted to give, and 3 cents more than anyone wanted.

 

Alot of good points here.

 

Impossible to get a straight answer for psi from anyone. Way to many variables- everyone has different size tires, tire ratings/category, wheights of vehicles with add ons like camper/racks/tents/bumpers/armor. Maybe try looking up videos on tire chalk test. That can get you in a good range. You wanna be warmed up though because the psi could climb maybe 4 or 5 psi.

 

Sounds about right.

 

Sounds like about the exact same mpg I get in town and on highway. I have the “trip mpg” as one of my chosen viewpoints in the cluster display and so I’m always aware of what each trip nets as far as mpg for the trip. My highway trips are always about 17-18 unless super windy (then it’s 15-16) and in town I’m like 12-14.

Note this is both before and after my 5.29 regear. I never got good mpg on either stock gears or the 5.29s, but 5.29s didn’t really hurt anything except mpg at maybe 80-85+, but it was never good there to begin with either.

I don’t know how people achieve above 20, they just drive painfully slow and grandpa-like to do so; couldn’t be me.

Tire pressure should be at the stock rec for a stock tire. That is where the tire properly carries the load the truck is intended to have, and extra air is only going to wear the center worse and also ride more harshly. No need to run more air and I’d suggest lowering it down and if you ever change tire sizes, adjust accordingly based on the tire pressure calculator. For me and 265/75R16 that means 27 psi, and they run great.

 

I'm running 36 front and 34 rear.
MPG is generally better with it like that but also my MPG is all over the damn place. I range from 15 (a few times less than that) to like 21 or 22 on rare occasions. Seems to be more tied to AC usage than it does the skinny pedal because I usually drive it like a grandpa. I'd guess my lifetime average is at around 17 or 17.5 MPG.

Considering the Overland Taylor (Tailor?) Tune.

The 2019 Ranger 2.3 Turbo Ecoboost that I traded for this truck was advertised as 20MPG but I routinely got better at around 22 on the regular and that was with larger off road tires and no speedo / odo calibration. Trouncing it to get on the free way and clean out the cats didn't seem to make a difference either.

 

Thanks for all the replies everyone.
Per soundman98's advice, the last couple of days I've been trying to get in 3rd gear by 20mph. Usually, I would be in 3rd by 25 or sometimes 30 mph. Love to wind it up in the manual!
It just never registered with me that those little extra rpm's could make such a difference. So I've upped my mpg to 17 to 20.5 per trip around town. I can live with that. It's not great, but it is what it is. At least it's better than what I was previously getting for MPG.

 

That's the rub isn't it. The Toyota 3.5 V-6 is a high revving engine. Makes all the power and torque somewhere north of 4500 rpm. So if you drive it there the MPG falls off. But if you drive it to get the advertised 20MPG, then its a sluggish dog.