Great HWY mpg… (1 Viewer)

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I’m running 275/60/r20 bfg’s on stock rims. At 75mph, my dash is saying 16mpg. At 80mph, it drops to 15mpg. No way in hell could you run 85 mph in this rig and get 20mpg. I think it’s physically not possible when stock.
I didn’t see that part.

I have a long history of noticeably better mileage at altitude than down near sea level where I live, but 20mpg at 85-90 is pretty far out there.
 
My highway miles are done in Texas between Austin to East of Houston and back. Once a year run to Missouri and recent trip Iowa and back. I see from 14 to 17mpg depending on wind direction, hills, and fuel I use. I spend most of my time +9 over posted (79 to 89 mph). I got lucky once on trip from Austin to Missouri and was able to get straight 89 octane gas (zero ethanol). I got about 17.5mpg for both tanks running about 80 to 84 with no wind. I have never seen 18mpg. If I am pulling my boat I see 12.5 to 13.5 trans in 6th and same +9 over posted. 2016 with stock size tires Nitto Terra Grappler G2, stock everything else. While I would love to see 20mpg I doubt it will ever happen speed limits are just to high hear in TX for that to happen.
 
2017 50k stock, i drive 80 very flat highway miles daily at 65-75 mph and about 6 miles around 35-45. Steady 15.8mpg, i get excited when it occasionally goes to 15.9
 
I have a long history of noticeably better mileage at altitude than down near sea level where I live, but 20mpg at 85-90 is pretty far out there.
Ditto. The higher the altitude the less wind resistance. Less wind resistance means better mpg. This is why most commercial flights reside in high altitude. I've had a 15-20mph wind at my back in TX running 75-80 and hitting 20-22mpg. I drove into a direct 20-30mph headwind in KS traveling 60mph and had 14-17mpg.

With no wind, on a flat highway, no matter how stock is your rig, obtaining over 21mpg running over 78+mph is not realistic.

Remember, these things impact your mpg:
  • Tires definitely impact it: size, materials, psi, wheel spacers, etc. Big mudders on spacers will definitely lower it.
  • Cargo/racks on top will lower it.
  • Big heavy bumpers will lower it.
  • A lifted suspension will lower it.
  • Driving into a headwind will lower it, being pushed by it will increase it.
  • All city driving will lower it.
  • The quality of the maintenance items and their remaining life will impact it.
  • Having stuff on a hitch whether a trailer or bikes hanging off the rear will lower it.
  • Exceeding 3k rpm will definitely lower it. If you drive your rig like Maverick pushed his ride then forget about it.
Someone at my son's school recently got a 200 series that is lifted 2-3", has big mudders with spacers, aftermarket roof rack, heavy front bumper, etc. He's never achieved over 13-15mph on the highway here in CO, at higher altitude than most other states.

We got our 2008 rig 1249 days ago. From then I've driven 54,600 miles in it from CO to MI to AL and everywhere in-between. Besides dash cams, cb radio, it's 100% stock. It's normal for the mpg to be in the 20-22 range on the highway (70-75 mph) fully loaded and unloaded.

This week I'm changing the tranny fluid, steering fluid, spark plugs, pcv valve, serpentine belt, wipers, both diff fluids, brake fluid, greasing the zerks, engine oil/filter and a few more things. All of this will improve the mpg for my trip to MI this month, which will bring me some happiness because going to MI when it's cold is usually not on my bucket list.

FYI - I put Yokohama Geolander A/T G015 tires on about 46,100 miles ago. The tread is holding up very well, maybe has about 15-20k miles remaining. Over 50% of the miles with the rig being fully loaded on the inside. I love these tires... very quiet on the highway, great in the rain, great on dry, good enough for snow and the trails.
 
I personally believe Toyota adjusting fuel injection quantities for the lower atmospheric pressure is also a factor.
 
Ditto. The higher the altitude the less wind resistance. Less wind resistance means better mpg. This is why most commercial flights reside in high altitude. I've had a 15-20mph wind at my back in TX running 75-80 and hitting 20-22mpg. I drove into a direct 20-30mph headwind in KS traveling 60mph and had 14-17mpg.

With no wind, on a flat highway, no matter how stock is your rig, obtaining over 21mpg running over 78+mph is not realistic.

Remember, these things impact your mpg:
  • Tires definitely impact it: size, materials, psi, wheel spacers, etc. Big mudders on spacers will definitely lower it.
  • Cargo/racks on top will lower it.
  • Big heavy bumpers will lower it.
  • A lifted suspension will lower it.
  • Driving into a headwind will lower it, being pushed by it will increase it.
  • All city driving will lower it.
  • The quality of the maintenance items and their remaining life will impact it.
  • Having stuff on a hitch whether a trailer or bikes hanging off the rear will lower it.
  • Exceeding 3k rpm will definitely lower it. If you drive your rig like Maverick pushed his ride then forget about it.
Someone at my son's school recently got a 200 series that is lifted 2-3", has big mudders with spacers, aftermarket roof rack, heavy front bumper, etc. He's never achieved over 13-15mph on the highway here in CO, at higher altitude than most other states.

We got our 2008 rig 1249 days ago. From then I've driven 54,600 miles in it from CO to MI to AL and everywhere in-between. Besides dash cams, cb radio, it's 100% stock. It's normal for the mpg to be in the 20-22 range on the highway (70-75 mph) fully loaded and unloaded.

This week I'm changing the tranny fluid, steering fluid, spark plugs, pcv valve, serpentine belt, wipers, both diff fluids, brake fluid, greasing the zerks, engine oil/filter and a few more things. All of this will improve the mpg for my trip to MI this month, which will bring me some happiness because going to MI when it's cold is usually not on my bucket list.

FYI - I put Yokohama Geolander A/T G015 tires on about 46,100 miles ago. The tread is holding up very well, maybe has about 15-20k miles remaining. Over 50% of the miles with the rig being fully loaded on the inside. I love these tires... very quiet on the highway, great in the rain, great on dry, good enough for snow and the trails.
21 mpg fully loaded at 70 mph is simply impossible. These things weigh 6k lbs unloaded, have high ground clearance, and are shaped like a brick. The faster you go, the more drag you have. Don’t get me wrong, I love my rig, but I’ve never seen 20 mpg, ever. The epa mpg tells the story. 13 city, 17 highway. Pretty damn accurate.
 
21 mpg fully loaded at 70 mph is simply impossible. These things weigh 6k lbs unloaded, have high ground clearance, and are shaped like a brick. The faster you go, the more drag you have. Don’t get me wrong, I love my rig, but I’ve never seen 20 mpg, ever. The epa mpg tells the story. 13 city, 17 highway. Pretty damn accurate.

Not impossible. It's been achieved many times.

Here ya go:

The EPA statements for mpg on any vehicle is an average for the country and for most drivers, and, I have no doubt politics is involved with the numbers.

What non-stock items do you have on your rig?
On the driver spectrum, do you land on the aggressive push-the-rpm over 3k side, or do you keep your accelerations below 2.7k?
What are the specs and psi of your tires?
Are the maintenance items of high quality and up-to-date?
 
The EPA statements for mpg on any vehicle is an average for the country and for most drivers, and, I have no doubt politics is involved with the numbers.

Semantics but the EPA statements for mpg are based on that vehicle performing a preset drive cycle. The drive cycle is intended to reflect a realistic average of how people drive their cars, which does make those numbers pretty reasonable for most people. I can't remember the year most of the numbers were adjusted downward to reflect changes in driving habits since the testing was first developed.. but it was a significant difference.

21 mpg fully loaded at 70 mph is simply impossible. These things weigh 6k lbs unloaded, have high ground clearance, and are shaped like a brick. The faster you go, the more drag you have. Don’t get me wrong, I love my rig, but I’ve never seen 20 mpg, ever. The epa mpg tells the story. 13 city, 17 highway. Pretty damn accurate.

Weight has little to do with fuel efficiency on the highway as long as tires are properly inflated. Your other factors.. yes.

It actually impresses me how far toyota went to make these things as slick as possible. One example that stands out to me is the fact that I and many others report cross winds impacting mileage more than headwinds. What this tells me is that despite the bulk Toyota's aero people did a lot to optimize the flow of air around the vehicle at those speeds.. and a significant imbalance such as a stiff cross-wind can upset that airflow management enough to need more horsepower than an equal headwind.

Which is just to say toyota clearly made these bricks as slick as possible. The mileage being so much better than an 80 or 100 isn't just the more modern engine.
 
Not impossible. It's been achieved many times.

Here ya go:

The EPA statements for mpg on any vehicle is an average for the country and for most drivers, and, I have no doubt politics is involved with the numbers.

What non-stock items do you have on your rig?
On the driver spectrum, do you land on the aggressive push-the-rpm over 3k side, or do you keep your accelerations below 2.7k?
What are the specs and psi of your tires?
Are the maintenance items of high quality and up-to-date?
I’m running taller bfg’s. 275/60/r20’s. I typically run 75mph and get 15-16mpg.
 
I’m running taller bfg’s. 275/60/r20’s. I typically run 75mph and get 15-16mpg.
This could (possibly) lower your mpg. As @bloc noted, is the psi correct for the tires? Have you reviewed the list I provided, compared to your situation, to discover why your mpg is never above 17? The things on the list aren't bad things, but they are things to consider when evaluating mpg on an individual basis. I'll be glad to audit your situation for $499 + tax ;) and tell you what you already know.


Semantics but the EPA statements for mpg are based on that vehicle performing a preset drive cycle. The drive cycle is intended to reflect a realistic average of how people drive their cars, which does make those numbers pretty reasonable for most people. I can't remember the year most of the numbers were adjusted downward to reflect changes in driving habits since the testing was first developed.. but it was a significant difference.

Weight has little to do with fuel efficiency on the highway as long as tires are properly inflated. Your other factors.. yes.

It actually impresses me how far toyota went to make these things as slick as possible. One example that stands out to me is the fact that I and many others report cross winds impacting mileage more than headwinds. What this tells me is that despite the bulk Toyota's aero people did a lot to optimize the flow of air around the vehicle at those speeds.. and a significant imbalance such as a stiff cross-wind can upset that airflow management enough to need more horsepower than an equal headwind.

Which is just to say toyota clearly made these bricks as slick as possible. The mileage being so much better than an 80 or 100 isn't just the more modern engine.

I concur with @bloc .

I was traveling due east on 70 in KS humming at 75 mph and per the dash getting about 21 mpg. The wind direction was directly due east. The winds shifted due southeast. Mpg dropped to high teens. I've gone through the Midwest, CO, and TX many times and experienced cross winds disrupting the "normal" positive and negative air pressures the Toyota engineers designed for the 200. I've had mine from unloaded to fully loaded hitting 75 mph on flat highways. Mpg is about the same.

I should be installing new NGK Iridium IX's right now... oh the distractions of this forum...
 
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I personally believe Toyota adjusting fuel injection quantities for the lower atmospheric pressure is also a factor.

Not sure what this means. But fueling is not adjusted statically for one use case or another. The maps are calibrated full the full spectrum of like environmental conditions... Barometric pressure, weather, temp etc...
 
Not sure what this means. But fueling is not adjusted statically for one use case or another. The maps are calibrated full the full spectrum of like environmental conditions... Barometric pressure, weather, temp etc...
Right, that's why I said "a" factor.. implying there are others at play. I actually forgot to toss "timing" into that sentence as well. Increased throttle opening allowing less pumping losses are another, now that we are getting more detailed.

My broader point is it may not merely be reduced HP demands from thinner air creating less drag, but also how efficiently the engine can make that horsepower.
 
I average around 13-14mpg. I haven't looked to see what I get on the freeway but I seriously doubt it's ever over 20mpg. Even with the rig stock, unloaded with only 285/75/17 AT3Ws, never over 13-14 mpg average here in Denver. Granted my work commute is 50/50 city/highway, so that's not helping...
 
I’m running 275/60/r20 bfg’s on stock rims. At 75mph, my dash is saying 16mpg. At 80mph, it drops to 15mpg. No way in hell could you run 85 mph in this rig and get 20mpg. I think it’s physically not possible when stock.

I get 20 and change highway going 80ish. Completely stock.
 
I use the Fuelly app to keep track of all of my fuel useage and i've averaged 14.9mpg over the last 15k miles in the LX. Best so far is 18.4.
My 80 has averaged 12.2mpg over the last 58k miles. All this is calculated based on miles driven divided by the gallons it takes to refill. None of this computer in the dash stuff. Fuelly is so nice for keeping track of all the fuel costs and mileage.
 
‘09 LX 88k miles, stock, 285/50/20 g015’s, can’t get over 16 mpg on flat highway in Oregon at 73mph. Get 9-11 towing our 4K lb loaded trailer.

Always have run 92 octane. My 100 lx dropped 3mpg running 87 and had noticeable power loss, so have always deferred to 92.
 
Regularly saw 10mpg driving around anchorage. Can get 17-19 at 60 and then 16ish at 85. Flat ground.
Was that on the Interstate? Oh....wait, there aren't any in Alaska. :) And the 85 you were doing must have been between Anchorage and Eagle River. Ahh....can you tell I miss my childhood in Anchorage?
 

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