Lexus IS 350 F Sport Fuel Economy: Real-World MPG Testing
The first time you merge onto a highway in a Lexus IS 350 F Sport, the 3.5-liter V6 pulls strong and the exhaust note sharpens — but you can’t help wondering if that premium fuel is burning a hole in your pocket with every mile.
TL;DR
The Lexus IS 350 F Sport gets official EPA ratings of 19 mpg city, 26 mpg highway, and 22 mpg combined for AWD models, while RWD versions are slightly better at 20/28/23 mpg. In the real world, owners typically see around 20.8 to 21.9 mpg in mixed driving, though these numbers vary widely depending on how you drive and where you drive. The premium fuel requirement adds to running costs, but the naturally aspirated V6’s character and Lexus reliability help justify the price at the pump.
Key Takeaways
- EPA estimates: AWD gets 19/26/22 mpg (city/highway/combined); RWD gets 20/28/23 mpg
- Real-world results: Around 20.8 to 21.9 mpg in mixed driving, based on actual testing
- Drivetrain matters: AWD models use a 6-speed automatic, RWD models use an 8-speed, and that extra gear helps highway efficiency
- Premium fuel is required, which means higher costs at the pump than regular-grade competitors
- Your driving mix makes a huge difference — one tester got 24.4 mpg with a 45% city/55% highway blend, while another got 20.8 mpg with 80% city driving
What the EPA Says vs. What You’ll Actually Get
Let’s start with the official numbers.
AWD IS 350 F Sport: 19 mpg city / 26 mpg highway / 22 mpg combined
RWD IS 350 F Sport: 20 mpg city / 28 mpg highway / 23 mpg combined
That difference between AWD and RWD? It’s real. The AWD model uses a 6-speed automatic transmission, while the RWD version gets an 8-speed with more gears to keep the engine in its sweet spot. More gears typically mean better highway fuel economy, and the numbers back that up.
So what do these numbers look like in the real world? Consumer Guide tested a 2019 IS 350 AWD F Sport and recorded 21.9 mpg over a mix of 55% city and 45% highway driving. That’s actually a hair better than the combined EPA estimate of 21 mpg for that model year.
A 2021 AWD test showed a combined average of 20.8 mpg with an 80% city driving mix — right in line with expectations for stop-and-go traffic. The same test also recorded a 64.4-mile stint with 45% city driving that returned a commendable 24.4 mpg. That 3.6 mpg difference from the combined EPA estimate shows just how much your driving conditions matter.
“This tester’s 64.4-mile stint with 45 percent city-style operation averaged a commendable 24.4 mpg.”
RWD vs AWD: The Fuel Economy Trade-Off
The RWD IS 350 F Sport is the more efficient choice. The 8-speed transmission helps the V6 work less at highway speeds, and there’s less drivetrain drag from the rear-wheel-only setup.
The fuel economy difference between RWD and AWD is noticeable:
| Model | City | Highway | Combined |
|---|---|---|---|
| RWD | 20 mpg | 28 mpg | 23 mpg |
| AWD | 19 mpg | 26 mpg | 22 mpg |
The gap is 1-2 mpg across the board. Not huge, but not nothing either. If you drive 15,000 miles a year, that roughly translates to a few hundred dollars in extra fuel costs for the AWD.
Chart: EPA vs Real-World MPG for IS 350 F Sport AWD
What’s Under the Hood?
The IS 350 F Sport uses a 3.5-liter naturally aspirated V6 producing 311 horsepower and 280 lb-ft of torque. It’s the same engine that’s been in the IS for years — which is either a good thing (proven reliability) or a bad thing (not class-leading fuel efficiency), depending on your perspective.
The engine is paired with either a 6-speed automatic in AWD models or an 8-speed automatic in RWD models. Both are traditional torque-converter automatics, which are generally less efficient than modern dual-clutch transmissions but offer smoother shifting for daily driving.
Premium fuel is required, so you can’t cheat by filling up with regular. The fuel tank holds 17.4 gallons, which means a highway range of around 487 miles in RWD models.
Comparison Table: IS 350 F Sport Fuel Economy vs Competitors
| Model | Engine | City MPG | Highway MPG | Combined MPG | Fuel Type |
|---|---|---|---|---|---|
| Lexus IS 350 F Sport RWD | 3.5L V6 | 20 | 28 | 23 | Premium |
| Lexus IS 350 F Sport AWD | 3.5L V6 | 19 | 26 | 22 | Premium |
| BMW 330i xDrive | 2.0L Turbo 4-cyl | 25 | 34 | 28 | Premium |
| Genesis G70 3.3T AWD | 3.3L Twin-Turbo V6 | 17 | 25 | 20 | Premium |
| Acura TLX A-Spec AWD | 2.0L Turbo 4-cyl | 21 | 29 | 24 | Premium |
The IS 350 F Sport isn’t the most fuel-efficient car in its class. The BMW 330i with its turbocharged four-cylinder is significantly thriftier. But the Lexus competes with the Audi S4, Genesis G70, and Acura TLX Type-S in the V6-performance luxury sedan space, and its numbers are comparable to those cars.
Tips to Maximize Your IS 350 Fuel Economy
The IS 350 F Sport is a sports sedan, not a hypermiler, but there are things you can do to stretch that tank of premium fuel.
1. Use Eco Mode. The F Sport has a drive mode selector with Eco, Normal, Sport S, and Sport S+ modes. Eco mode adjusts throttle response and transmission behavior to prioritize fuel efficiency over performance.
2. Watch your right foot. The 3.5-liter V6 loves to rev, and it’s tempting to let it. But every time you floor it, you’re watching the gas gauge move.
3. Keep up with maintenance. Properly inflated tires and fresh engine oil help the engine run efficiently. The IS uses synthetic oil, so stick to the recommended intervals.
4. Highway cruising is your friend. The IS 350 is genuinely efficient on the highway — one tester saw 24.4 mpg with a highway-heavy route. If you’re doing long road trips, the IS won’t punish you at the pump.
5. Consider RWD if you don’t need AWD. Those 2 mpg difference across the board adds up over time. If you don’t deal with snow regularly, the RWD car saves fuel and is more engaging to drive.
“The 3.5-liter V6 is naturally aspirated in an era where that’s increasingly unusual. It has character, a decent sound, and proven reliability — but it’s not a fuel-efficiency champion.”
FAQ
What is the real-world mpg of the Lexus IS 350 F Sport?
In real-world testing, the AWD version typically delivers 20.8–21.9 mpg in mixed driving. Highway-heavy routes can exceed 24 mpg.
Which IS 350 F Sport gets better fuel economy, RWD or AWD?
The RWD model gets better fuel economy: 20/28/23 mpg compared to the AWD’s 19/26/22 mpg.
Does the Lexus IS 350 F Sport require premium fuel?
Yes, premium unleaded fuel is required for the 3.5-liter V6 engine.
How does the IS 350 F Sport’s fuel economy compare to its competitors?
The IS 350 is comparable to twin-turbo V6 competitors like the Genesis G70 3.3T (17/25/20 mpg) but less efficient than turbocharged four-cylinder rivals like the BMW 330i (25/34/28 mpg) because it’s naturally aspirated.
Why does the AWD model get worse fuel economy than RWD?
The AWD model uses a 6-speed automatic transmission versus the RWD’s 8-speed, and the added weight and drivetrain friction of all-wheel drive hurt efficiency.
Final Thoughts
The Lexus IS 350 F Sport’s fuel economy is what you’d expect from a naturally aspirated V6 sports sedan in 2024: not great, not terrible. It’s more thirsty than a turbocharged four-cylinder, but thriftier than twin-turbo V6 competitors.
The real-world numbers are close to the EPA estimates, which is refreshing in an era of overly optimistic rating. If you’re looking for a V6-powered luxury sedan with character, reliability, and reasonable — if not exceptional — fuel economy, the IS 350 F Sport delivers. Just budget for premium fuel and keep that Sport S+ mode for special occasions.
What’s your real-world IS 350 fuel economy? Share your experience and driving mix in the comments.
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