The Lexus GX does 16.1 mpg combined (14.7 city, 19 highway), which works out to about $2,385 a year in fuel at $3.20 a gallon and 12,000 miles. Engine choice matters more than you'd think: 3.4L 6-cyl does 17 mpg while 4.7L 8-cyl does 15 — a difference of $301 a year. Against other V8 cars it sits above the average of 16.1 mpg.
Every Lexus GX engine, compared
Gas mileage on the Lexus GX ranges from 17 down to 15 depending on which engine sits under the bonnet — a spread of $301 a year across 3 versions of the same car. Picking the right one often saves more fuel than picking a different car altogether. Yearly cost assumes 12,000 miles at $3.20 a gallon.
| Engine | Combined | City / Highway | Years | Fuel per year |
|---|---|---|---|---|
| 3.4L 6-cyl | 15 / 21 | 2024–2026 | $2,259 | |
| 4.6L 8-cyl | 15 / 19.3 | 2010–2023 | $2,327 | |
| 4.7L 8-cyl | 14 / 17.7 | 2003–2009 | $2,560 |
What that actually costs
The Lexus GX burns a gallon every 16.1 miles, so 12,000 miles takes about 745 gallons a year. At $3.20 that is what the table below adds up to.
| Measure | Value |
|---|---|
| Cost per mile | $0.199 |
| Fuel per year | $2,385 |
| Fuel over five years | $11,925 |
| Against other V8 cars | −$0 a year |
| EPA's own estimate | $4,673 a year |
City or highway — who is this car for
The Lexus GX gives up 4.3 mpg the moment you leave the motorway — 19 out there against 14.7 in town, a 29% drop worth $591 a year. A wide gap punishes stop-and-start traffic; a narrow one means the car doesn't care where you drive it.
| Measure | Value | Reading |
|---|---|---|
| City | 14.7 mpg | $2,612 a year if you only drive in town |
| Highway | 19 mpg | $2,021 a year if you mostly commute |
| Gap | +4.3 mpg (29%) | Typical for its type |
How the GX changed over the years
The GX peaked in 2026 at 17 mpg (15 city, 21 highway) and was at its thirstiest in 2009 at 15 — 2 mpg apart, or $301 a year in fuel between buying one year and the other. The 2026 car does 17. Jumps usually mark a new generation or a new engine; dips often mean a heavier body or added all-wheel drive.
| Model year | Combined | City / Highway | Engines offered | Fuel per year |
|---|---|---|---|---|
| 2026 | 15 / 21 | 1 | $2,259 | |
| 2025 | 15 / 21 | 1 | $2,259 | |
| 2024 | 15 / 21 | 1 | $2,259 | |
| 2023 | 15 / 19 | 1 | $2,400 | |
| 2022 | 15 / 19 | 1 | $2,400 | |
| 2021 | 15 / 19 | 1 | $2,400 | |
| 2020 | 15 / 19 | 1 | $2,400 | |
| 2019 | 15 / 18 | 1 | $2,400 | |
| 2018 | 15 / 18 | 1 | $2,400 | |
| 2017 | 15 / 18 | 1 | $2,400 | |
| 2016 | 15 / 20 | 1 | $2,259 | |
| 2015 | 15 / 20 | 1 | $2,259 | |
| 2014 | 15 / 20 | 1 | $2,259 | |
| 2013 | 15 / 20 | 1 | $2,259 | |
| 2012 | 15 / 20 | 1 | $2,259 | |
| 2011 | 15 / 20 | 1 | $2,259 | |
| 2010 | 15 / 20 | 1 | $2,259 | |
| 2009 | 14 / 18 | 1 | $2,560 | |
| 2008 | 14 / 18 | 1 | $2,560 | |
| 2007 | 14 / 18 | 1 | $2,560 | |
| 2006 | 14 / 18 | 1 | $2,560 | |
| 2005 | 14 / 18 | 1 | $2,560 | |
| 2004 | 14 / 17 | 1 | $2,560 | |
| 2003 | 14 / 17 | 1 | $2,560 |
MPG is a number. Dollars per year is the answer.
- Fuel profile built from your actual mileage and local prices
- Fuel tracker: what you really spend, month by month
- Insurance and fuel folded into 5-year cost to own
- Compare any two cars on total cost, not sticker price
- No ads, no tracking — and much more
How we count
This page rests on 24 EPA ratings of the Lexus GX — 3 engines across 2003–2026. The mileage is EPA's laboratory figure, unchanged; the yearly bill is ours, at 12,000 miles and $3.20 a gallon, against EPA's own estimate of $4,673. Full method.
Frequently asked questions
What mpg does the Lexus GX get?
16.1 mpg combined on average — 14.7 in the city and 19 on the highway, per EPA ratings across 2003–2026.
How much does a Lexus GX cost in fuel per year?
About $2,385 at 12,000 miles and $3.20 a gallon — roughly $11,925 over five years, or 0.199 dollars a mile.
Which GX engine is the most economical?
The 3.4L 6-cyl at 17 mpg, against 15 for the 4.7L 8-cyl — a difference of about $301 a year.
Is the GX good on fuel compared with similar cars?
Against other V8 cars it sits above the average of 16.1 mpg, computed across 3323 ratings.
Are these real-world GX figures?
No — they are EPA laboratory ratings, the same ones printed on the window sticker, and EPA's own annual fuel estimate for the Lexus GX is $4,673 against the $2,385 we compute at 12,000 miles. Expect a little worse in practice: the spread between the 17 and 15 mpg versions of this car is smaller than the spread between two drivers of the same one.
Mark ForCar as a preferred source and our data shows up first in your Google results. One click, no account.