Over time, Lexus has put in a lot of effort to make GX 550 the star of the show. And that’s pretty evident. For instance, the 2025 GX 550 offers nearly everything one could dream of in a luxurious SUV. However, some owners and interested folks want to know the Lexus GX 550 Gas mileage.
Well, GX is one full time 4×4 SUV, so I’m not sure its MPG rating should matter to any of its buyers. Anyhow, I still wrote this guide for you after fully testing my GX 550 Overtrail for a week. So, here’s all I got!
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Table of Contents
- What Is the Real MPG of the GX550?
- How Many Miles Per Gallon Does A Lexus GX 550 Premium Get?
- Lexus GX 550 Gas Mileage – Trim by Trim
- Does The Lexus GX550 Require Premium Gas?
- How Big Is the Gas Tank on A 2025 Lexus GX 550?
- Is The Lexus GX 550 Hybrid?
- Does the Lexus GX 550 Have The Same Engine As The Tundra?
- Lexus GX 550 Gas Mileage – Final Thoughts!
What Is the Real MPG of the GX550?
Practically speaking, the Lexus GX 550 delivers 15 MPG within city and 21 miles per gallon on highway. That’s the real MPG of GX 550 according to EPA. During my testing, I also recorded pretty much the same fuel economy figures. I drove my GX 550 OT in both city driving conditions and on highways. I was able to record around 18 MPG (combined).
For a V6 powered full time 4×4 SUV, I think it’s pretty good. Some owners even claimed around 22 MPG on highway. Well, that might be possible given the fact that you drive with a very light foot.
How Many Miles Per Gallon Does A Lexus GX 550 Premium Get?
As mentioned before, you can expect around 15 miles per gallon from GX 550 in city driving conditions.
On highways, GX 550 can deliver as good as 21-22 MPG. In Short, the combined Lexus GX 550 gas mileage is around 17-18. Again, for a V6 Powertrain, it’s not bad at all.
Lexus GX 550 Gas Mileage – Trim by Trim
Here is a table that highlights the GX 550 MPG for all trim levels. Have a look at it here:
| Trim | City MPG | Highway MPG | Combined MPG |
|---|---|---|---|
| GX 550 Premium | 15 | 21 | 17 |
| GX 550 Premium+ | 15 | 21 | 17 |
| GX 550 Luxury | 15 | 21 | 17 |
| GX 550 Luxury+ | 15 | 21 | 17 |
| GX 550 Overtrail | 15 | 21 | 17 |
| GX 550 Overtrail+ | 15 | 21 | 17 |
Does The Lexus GX550 Require Premium Gas?
Yes, the GX 550 requires premium gas (91 Octane) to delivers its best performance. That’s mainly because Lexus has tuned the GX so it performs at its best when driven with 91 octane. Many owners and enthusiasts reported this concern on Reddit. I always drove GX 550 on 91 octane, and it performed like a beast.
So, I’d also recommend using premium gas to get the most out of it. Please also note, using ordinary fuel not just hinders performance, but can also be one major reason for poor fuel economy.
However, there is also another school of thought. Some owners reported that GX’s ECU is programmed in such a way that it automatically adjusts the overall performance based on the type of fuel you put in. I’m not sure how true this statement is. So, better stick with the premium gas if you really want to enjoy the premium SUV.
How Big Is the Gas Tank on A 2025 Lexus GX 550?
2025 Lexus GX 550 has 21.1 Gallons of fuel tank capacity. In litres, it turns out to be 79.84, which is standard for SUVs these days. The GX 460 has 23 gallons and the 550 has 21 Gallons of fuel tank.
The reduced fuel tank capacity aims to improve the overall fuel economy of the SUV. Some owners also believed that it helps the manufacturer cut some cost. Whatever the case may be, 21 gallons should be enough to conquer a variety of terrains.
Is The Lexus GX 550 Hybrid?
There isn’t any hybrid powertrain option available for GX 550 till now. The latest 2025 model (all trims) come equipped with 3.4-liter twin turbocharged engine that boosts 349 HP and 479 lb-ft of torque.
However, it is rumoured that Lexus is working on a hybrid powertrain for the upcoming GX. As of now, there hasn’t been any official announcement made or shared by the company.
Does the Lexus GX 550 Have The Same Engine As The Tundra?
While covering the Lexus GX 550 gas mileage, I also came across this query. Well, technically, yes, both share the same engine. The displacement is the same, but the horsepower and torque figures are different.
During testing, I found Lexus has tuned the GX’s powertrain in a different way. Its turbocharger is slightly reduced (maybe for better MPG rating). So GX produces a bit less power compared to Toyota Tundra. This is one main reason GX requires premium gas, whereas Tundra doesn’t.
Lexus GX 550 Gas Mileage – Final Thoughts!
So, that’s pretty much it. I won’t drag this query too long as I’ve already covered it. So, yes you the Lexus GX 550 MPG ratings are 15 city and 21 highways. Also, the Lexus GX 550 fuel tank capacity is 21 gallons. That summarizes the GX 550’s fuel economy for 2025.
Planning to buy a used GX or want to upgrade an existing one? Either case, Flex Automotive has got you covered. We have tons of GX 550 in our inventory. Plus, we also customize GX 550 the way you want. Wanna try? We’d love to assist you!
