GX550 Real World MPG

JPE said:

Just so you know, it's likely (although I am admittedly not sure) that the in-tank fuel pump uses the gasoline for lubrication. Assuming that's true, you don't want to regularly run your tank down past E because the fuel pump could eventually get damaged. Every once in a while, especially if you want to test and figure out just how much range you really have, won't be a problem, just don't make a habit of it.

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Ya, running tank down on E is never good for a fuel pump/system.

My gas light wasn’t even on when i filled up after i was nearing end of dealer full tank. Just thought i’d post my real world experience with the first full tank of gas owning the 550.

People on this thread posting 13 mpg’s and lower either have a heavier foot than me or live in vertical geography.

Also, still in break in period and not trying to hammer the gas. I did that in the tester on the lot 2 months ago, lol.

I’ve had my GX for a week and have 150 miles on it but averaging 11.5 mpg. I’m in the burbs (North ATL) and been mostly stop and go without much HWY travel yet. I was playing with the driving modes a good bit and the average was 10.5 but went up 1 mpg since swapping to eco only for the last 50 miles or so.

I would still expect to get at least 14 with stop and go. My 2018 Armada which I just replaced with the GX averaged 14-15.

What’s this about a break in period I’ve seen mentioned here? I didn’t really know that’s a thing.

WDEKH said:

I’ve had my GX for a week and have 150 miles on it but averaging 11.5 mpg. I’m in the burbs (North ATL) and been mostly stop and go without much HWY travel yet. I was playing with the driving modes a good bit and the average was 10.5 but went up 1 mpg since swapping to eco only for the last 50 miles or so.

I would still expect to get at least 14 with stop and go. My 2018 Armada which I just replaced with the GX averaged 14-15.

What’s this about a break in period I’ve seen mentioned here? I didn’t really know that’s a thing.

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This is what they recommend. Pretty much the same as what is in the owners manual: https://stagingsupport.lexus.com/s/...ext=To extend the life of,500 miles (800 km):

ksj said:

This is what they recommend. Pretty much the same as what is in the owners manual: https://stagingsupport.lexus.com/s/article/What-does-Lexus-recom-8219#:~:text=To extend the life of,500 miles (800 km):

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Thank you!

3oaks said:

I have 1,100 miles on my OT and been running almost exclusively in Eco mode, using 93 octane. About 50% on highway and rest in suburbia.
All miles to date in Iowa (rolling prairie, mild hills), and I’m not a small pedal abuser. Average to date mpg for suburban driving is 17.8, and 20.3 for highway.

Heading to Ouray/Silverton/Telluride at end of this month for some off-roading, will see how it handles the mountains.

Didn’t buy the OT for on-pavement prowess, but been very pleased with its mpg (which surprisingly is substantial improvement over my 2016 Land Cruiser). Hoping an aftermarket fuel tank available soon.

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Let us all know if you find an aftermarket auxiliary fuel tank.

13 mpg average. Mostly city.

Here is my solution for longer range pulling my RV trailer. Had my Gx550 for a week getting 12.5 mpg pulling 6,000 lb trailer at 60 to 65 mph on pretty flat hwy. I have 33 gallons in the 3 tanks with a pump and gas nozzle to refill as needed. 

How many miles do you have on the GX?

Nice Rig Rance......really extends your fuel range for towing.

I have 700 miles on it now as I drove across the state of Missouri with it without the trailer. I found the mpg to be better than expected showing 24.7 from Tulsa to ST. Louis as long as I let the GX550 drive itself with the speed set at 68 mph with 4 bars of separation on the adaptive cruise control. I am retired and not in a hurry LOL. I need as much range as I can get since, I will be traveling to Alaska from the Midwest in the summer of 2025 with my trailer. I found the factory roof rack to have wind noise starting at 60 mph and up but if I follow a tall Semi with the 4 bars of separation that stops the noise and seems to help take the wind off the GX550.

I am just trying to find out what speed is the peak efficiency for the GX550. The power train is super smooth and powerful. I have a Genesis GV80 3.5 liter twin turbo also which I do better on MPG but it can't tow or off road like this Lexus can. It's the aerodynamics that really hurts the mpg when you go past 70 mph on the GX550.

With all the fuel onboard the tongue wt. is 1,000 ibs which pushes the GX550 down 2 inches at the wheel well. It actually looks level with that load on it.

In 2004 I bought a new 2004 GX470 which I still own. I never got over 19.5 mpg with it no matter how easy I drove it. After I put 35-inch tires on it & lifted it the mpg went to 16.5. Now I have a TRD supercharger on it but have not tested the gas mileage on it yet.

Town driving kills the mpg on the GX550. It is just too easy to use the turbos with all that torque to move the 5,800 lbs around which my weighs. It weighs 11,800 with the trailer and all fuel tanks full.

Stupid question. How do you get the mpg ? I have the mpg gauge on but it seems to be getting the mpg since inception? Is there a way to get mpg per trip. Or how do you reset that counter? Sorry. Still learning. But it’s saying 9mpg on my screen (I have just been driving around in comfort mode) lux+

Avg 16.5. 700 miles, mixed driving.

ilumo said:

Stupid question. How do you get the mpg ? I have the mpg gauge on but it seems to be getting the mpg since inception? Is there a way to get mpg per trip. Or how do you reset that counter? Sorry. Still learning. But it’s saying 9mpg on my screen (I have just been driving around in comfort mode) lux+

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Hit the car icon then trip wil show current and history then you can reset

supersix said:

I thought it might be helpful to have some real world reports of fuel mileage on the new GX.


What’s your general mix of city/highway/offroad?

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Stock Overtrail. First 100 miles. 18.8 mpg. 80 percent highway driving at the speed limit. Minimal aggressive acceleration.

ilumo said:

Stupid question. How do you get the mpg ? I have the mpg gauge on but it seems to be getting the mpg since inception? Is there a way to get mpg per trip. Or how do you reset that counter? Sorry. Still learning. But it’s saying 9mpg on my screen (I have just been driving around in comfort mode) lux+

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Once you select the "update" option it will show your current average mpg since the update on this screen and on the gauge object. Also, it will briefly show you a trip summary every time you turn off your GX on your main gauge panel.

Don't feel stupid it takes a while to learn all the screen functions and where they are. Running around in St Louis I got 13.2 mpg. Heading back across Missouri I cleared the mpg data on the highway, driving in ECO mode with adaptive cruise set to 70 mph temp. 91 degrees outside temp. Mine is the Overtrail GX550. I got 23.4 mpg to Springfield Mo. Filled up at Costco in Springfield and reset the mpg data again. Set the cruise the same with 4 bars of separation between the Semi in front of me and made 25.2 mpg to Joplin, Mo. Any city driving just kills the mpg!

SethGX said:

Once you select the "update" option it will show your current average mpg since the update on this screen and on the gauge object. Also, it will briefly show you a trip summary every time you turn off your GX on your main gauge panel.

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Super helpful. Thanks so much!

rancejunge said:

Don't feel stupid it takes a while to learn all the screen functions and where they are. Running around in St Louis I got 13.2 mpg. Heading back across Missouri I cleared the mpg data on the highway, driving with adaptive cruise set to 70 mph temp. 91 degrees outside temp. Mine is the Overtrail GX550. I got 23.4 mpg to Springfield Mo. Filled up at Costco in Springfield and reset the mpg data again. Set the cruise the same with 4 bars of separation between the Semi in front of me and made 25.2 mpg to Joplin, Mo. Any city driving just kills the mpg!

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I have been doing a lot of local driving and I got the same as you 13.2 mpg. That said I used adaptive cruise for the first time today and it’s soooo much better than my Macan S. I even tried the lane keep feature and it was really cool (not sure I like the car in complete control though ).

I just completed a round trip vacation from Scottsdale to San Diego and back. The mapping program says it is 387 miles each way. I only drove about 25 or so miles while in San Diego for the week.

I have the Westcott Designs preload collar lift kit with 2.50” of lift in the front and .75” in the rear. I am running 35x12.5x17" aftermarket wheels and Toyo Open Country AT3 tires (same tires as stock but about 2.5" bigger in diameter). I also have a low-profile Westcott roof rack.

Based on mileage traveled as shown in mapping programs (google maps or the Lexus navigation system) vs. what my truck odometer records, my truck reads about 7.2% under actual. This is because my bigger tires are traveling farther with each revolution than the stock tires and the truck's odometer is calibrated for stock tires.

With all that figured into the equation, I averaged 14.66 mpg over 728 miles. This doesn't include the last 95 miles from Gila Bend to Scottsdale because I haven't filled up yet here in Scottdale and compared miles driven to gallons used since Gila Bend.

My driving conditions were fully loaded truck with 2 adults and 2 children age 6 and 9. The cargo area probably had about 250-300 lbs on the way there and 150-200 lbs returning. Average speed on the way there was probably about 80+ mph on the highways but I dialed it back on the way home to about 70-75 mpg to try to get better mileage. I did notice a difference at the lower speeds. It seems that you literally lose a tenth of a mpg for each couple mph over 70.

Interestingly, for all the previous miles before I installed the larger tires, I was only averaging about 14.2 mpg but a good majority of that was just around-town driving mostly in comfort mode with what I'd call a normal foot on the gas.

after 500 miles we are at 17.6 mpg