Gas mileage

I know all my Toyotas have never gotten good gas mileage especially when they are lifted, the dash says 12 mpg but idk how accurate that is because of the tires being bigger , anyone have an idea on this

 

How many miles have you driven? Mileage on these trucks vary tremendously on terrain, driving habits etc. I consistently get 21 in my 2019 trd off-road with stock tires. Have seen as high as 29 just cruising at 60ish and low as 16.5 going up “mount rose highway” in NV for 20 miles

 

Larger diameter tires will require correction for mileage and speed or re-calibration.

My '06 goes from the "F" to the "E", then I fill again to the "F" and repeat the cycle.

FWIW, my truck is stock, I regularly get 18-19 mpg. Using hand calculation.

 

According to the dashboard computation, I'm getting about 13 mpg in mostly stop-and-go city traffic. It improves a lot once I get out on the highway. But it's hard to tell for sure because the computer averages it all out.

 

Yes, it can vary A LOT, depending on how you drive, the terrain, lifting the truck, tires, etc. That all being said, one the transmission "learned" how I drive, since then, I have been getting the best gas mileage, WAY more than I had anticipated before purchasing the truck! I had already resigned myself to not getting good gas mileage, before I got the truck, but still, I figured it would be a sacrifice for such a great truck. But whoa! Now, I regularly get between 25-30mpg around town, and the same thing on the highway! Now, that being said, of course, when I am on an incline going up, then the dang thing downshifts one or two gears, the rpms SCREAM at me, and if I have the ECO screen on, I can see the mileage plummeting like a rock to 10mpg. But, once back on level ground, and at a constant rate of speed, it goes back up to between 25-30, averaging around 26-28. I have a TRD Sport with 6cyl. This is way better than my old 96 4cyl! I will include pics to prove what I am saying! Enjoy!

 

I normally get about 18-20 in the Mountains of SW Colorado @ 60/65 and as low as 14 towing and a best of 22 traveling. I just put 265/75/16 Cooper ST Maxx on, a 32” tall tire and my MPG is still about the same and my speedometer is still accurate, at 60, I am doing 60.6

 

It only has 200 miles on it but this isn’t my first Toyota truck,I know they don’t do well period especially when lifted and bigger tires, it’s all city driving so far , I was just curious if there was a way to mathematically to fig it , I bought this one already lifted by the dealer tires TRD pro rims everything already on it I can’t imagine that they recalibrated the computer for the tires

 

Mathematically....the calculation is very easy.

Next time you fill the tank, set the ZERO on one of the trip odometers.

Drive normally until next fuel fill. Record the mileage on the Trip Odometer. Record the number of gallons to fill your tank.

Now, just simply divide the 'Trip Odo mileage' by the 'gallons to fill' to discover the MPG of the last tank of fuel.

MPG = miles driven/gallons to fill.

This is the AVERAGE over a tank of fuel. The instantaneous numbers the truck's computer spits out are approximations at best.

I wouldn't consider instantaneous numbers as gospel, only as a guide to estimate the weight of your foot on the skinny pedal.


Also realize, your truck is new. It isn't "broken in" yet at 200 miles. Suggest to keep track of your miles, fuel on an Excel spreadsheet for several months to a year before you will have a good feel for your MPG.

 

My OVtuned 2019 Sport on stock wheels using built-in computer gets 18-20MPG with "normal" driving, 14-16 when I'm "playing" or in a hurry or driving over the passes into the next state. Computer says 330 miles left when I fill up.

 

Knute , well that’s not completely true , Because of the tires the miles that I’m traveling are not true so it’s not mathematically accurate bigger tires make less revolutions which would show less miles which was so less miles per gallon

 

I pay no attention to the estimates/current mpg reading in the truck, they seem all but useless. I hand calc my mpg after each fill up, pretty much dead on 17 consistently on every fill up. 265/75 E rated and rtt pretty almost completely above the roofline dragging me down, and a few hundred pounds of rack/sliders. I live in the foothills though, so very little flat ground. Truck is also primarily a weekend warrior, so it's usually loaded down with a bunch of gear as well.

 

It is true

You will need to correct your miles driven for the larger tires. See post #3. The MPG math remains the same.

I will suggest you take the truck back to Toyota and request them to re-calibrate the Odo and Speedo for the larger tires.

 

530taco, ya I can’t How do you calculate that because I have 285 75 16 tires so I know whatever mileage it tells me I’ve traveled is not accurate, there is a tire calculator on the Internet and the difference between 265s and 285s is huge on the speedometer

 

Top off tank. Track miles driven by gps to take out any anomalies with oversized or worn tires. Fill up tank again and divide the miles driven by gallons at fill up. It’s not that hard. If you’re somewhere in the 17-21MPG range, with the v6 engine and not hauling/pulling a payload, you’re doing fine. Less than that then you have something going on with the engine or you’ve done modifications that you should have known would affect it.

 

I replaced the OEM factory Goodyear tires with slightly larger (32") about 18 months ago. No other changes from OEM configuration, I have 67K total miles. You can see my fuel economy in my Fuelly .sig.

I had a 1980 Hilux, 2WD, standard cab/bed, with the 20R engine and 4 speed manual transmission, bone stock. I owned it from 1986 - 1997, put about 120K miles on it myself, on top of the 60K on it when I bought it from a family friend. That truck got around 17 - 19MPG. so as OP stated, even with all the technology advances in automotive engineering over the last 40 years, fuel economy has remained very poor. Now to be fair, my 2017 Off Road is a V6 (vs 4), and supposedly 275 HP (vs 95), and is fuel injected (vs carbureted), but still same fuel economy.

 

If you have 33" tires vs 30.5" tires, each one rev of the tire travels almost 8" more distance.
The consequences of this:
1. Your speedometer lies and you're really traveling faster than it says.
2. Your 33" tires revolve about 50 times LESS than with 30.5" tires over 1 mile.
3. Your odometer records less distance traveled over the course of one tank of fuel.
The math to determine a correction factor is beyond my brain's capacity on this Sunday.

 

Weight, safety equipment, electronics, and emissions. Seems every fuel efficiency gain is offset by these things. It's why I cringe when I see motorized tailgates and side mirrors. WTF.

I get about 25mpg on a long highway trip. 20-22 in mixed driving. But I'm very mindful about not wasting kinetic energy. Remember: Brakes turn gasoline into heat and dust.

 

Use the tire calc on here, do the same math and multiply your mpg by your tire % difference. 265/75 are 3% taller than 265/70. I multiply my miles driven/gallons filled by 1.03 to get my actual adjusted mpg. Looks like 285/75 is 7.3% bigger than 265/70 so you would just multiply your miles driven/gallons filled by 1.073 to get adjusted MPG. Same with your speedo, you're doing 64.38 mph at speedo 60 mph. Of course, this all assumes your truck was dead nuts calibrated from the factory, which in my experience it probably wasn't. My 265/75 read closer to my actual speed than the 265/70s did, using my uncles PD radar to verify.

 

Circumference ratio would be the correction factor.

 

Larger tires will cause speedometer and odometer to be inaccurate. You're driving farther and faster than either says. It isn't hard to figure out the percentage you're off. Most trucks will only be 3-5%, but if you go really big with aftermarket tires you could be 7-10% off. When figuring fuel mileage by hand just calculate for the percentage you're off.

For example if your new tires are 5% larger than stock simply multiply the miles on your odometer by 1.05 to get the true mileage. For example if your odometer says you drove 250 miles multiply 250 X 1.05= 262.5 miles actually driven. Then divide 262.5 by the amount of gas used.

This is more accurate, but it usually only improves fuel mileage by about 1/2 MPG. In rare cases closer to 1 MPG, but it ain't gonna show you getting 2-3 MPG better.

I think part of the bigger problem is that the speedometer is also reading slow. You may think you're driving 65 mph, but in reality you may be closer to, or over 70 mph. Driving faster hurts fuel mileage a lot. Especially at speeds over 60-65 MPH.