2008 Lexus IS 350: MPG and fuel economy

This page collects every fuel-economy figure the EPA publishes for the 2008 Lexus IS 350. Below you will find the headline combined, city, and highway MPG, the estimated annual fuel cost at three different driving levels, the tailpipe CO₂ emissions, and a full breakdown of the engine and drivetrain. If you want to know whether this generation got more or less efficient over the years, the year-over-year table further down covers every model year the EPA has rated.

Fuel economy at a glance

These are the EPA's official ratings for the 2008 Lexus IS 350. The numbers come from a standardised laboratory test cycle and are the same figures that appear on the window sticker of every new car. Real-world mileage varies with driving style, weather, fuel quality, and how heavily loaded the car is.

Combined MPG is a 55/45 weighted blend of the city and highway test cycles. The EPA uses it as the single number you can compare across the entire dataset, including hybrids and EVs (which use the equivalent MPGe figure).

How the 2008 Lexus IS 350 compares

The 2008 Lexus IS 350 returns 20 combined MPG. Cars in the Subcompact Cars class for the same model year average 20.8 MPG, which puts this car behind the class average by about 4%.

The most efficient car in the Subcompact Cars class for the 2008 model year is the MINI Clubman at 32 MPG. The bar chart below puts the Lexus IS 350 alongside the class best and the class average so you can see the full picture.

For broader context, the average new car of the 2008 model year (across all classes) returns 19.1 MPG. Larger vehicles pull the all-cars average down, so do not use that figure on its own to judge a small car or a hybrid. The full list of the most efficient cars of the 2008 model year is on its own page.

Annual fuel cost across driving patterns

The headline annual fuel cost the EPA publishes assumes 15,000 miles of driving per year and a fuel mix of 55% city and 45% highway. The dollar figure is calculated using the EPA's current reference price for premium gasoline, which is $4.61/gallon. EPA updates that reference periodically rather than tracking live pump prices, so treat it as a window-sticker estimate rather than today's pump number.

The table below scales the EPA's number to three common driving patterns. The combined MPG and the reference fuel price stay constant, only the annual mileage changes. To get a current-prices estimate, take your local gas price and multiply by 750 gallons (the car's annual consumption at the rated MPG).

Year-over-year MPG for the Lexus IS 350

The EPA has rated the Lexus IS 350 across 17 model years, from 2006 Lexus IS 350 through 2026 Lexus IS 350. The numbers below are the best combined MPG figure the EPA published for each year, which lets you see when the car was at its most efficient and how recent generations stack up.

Combined MPG has stayed in roughly the same range across the run. The peak rating came with the 2018 Lexus IS 350 at 23 MPG.

Compare against other Subcompact Cars for 2008

If you are cross-shopping the 2008 Lexus IS 350, the most useful comparison is against the other cars in the Subcompact Cars class for the same model year. The list below shows the highest-MPG peers, ranked from most to least efficient. Click any of them to open its full page.

The MINI Clubman leads this group at 32 MPG, 12 MPG ahead of the 2008 Lexus IS 350.

Specifications

The 2008 Lexus IS 350 runs a 3.5-liter 6-cylinder engine paired with a automatic (s6), sending power through rear-wheel drive.

Engine, transmission, and drivetrain together drive most of the variation in fuel economy across trims. A larger engine moves the car with less effort but burns more fuel. A turbo lets a small engine punch above its weight, often without much MPG penalty. All-wheel drive adds traction and weight, and usually costs a couple of MPG compared with two-wheel drive of the same engine.

Vehicle class

Subcompact Cars

Engine

3.5L 6-cylinder

Transmission

Automatic (S6)

Drivetrain

Rear-Wheel Drive

Fuel type

Premium

Annual petroleum use

14.9 barrels per year

Common questions about the 2008 Lexus IS 350

Quick answers to the questions people most often search for when looking up the 2008 Lexus IS 350.

• Is the 2008 Lexus IS 350 fuel efficient?

  It is in line with the rest of the class. The 2008 Lexus IS 350 returns 20 combined MPG, and the average car in the Subcompact Cars class for the same model year sits at 20.8 MPG.
• What MPG does the 2008 Lexus IS 350 get?

  The EPA rates the 2008 Lexus IS 350 at 20 combined MPG, 18 MPG in city driving, and 25 MPG on the highway. Real-world numbers depend on your driving style, the weather, and how loaded the car is.
• How much does it cost to fuel a 2008 Lexus IS 350 per year?

  The EPA estimates an annual fuel cost of $3,450 for the 2008 Lexus IS 350. That figure assumes 15,000 miles of driving per year, a 55% city and 45% highway split, and the EPA's published average fuel price for the rated fuel grade.
• Does the 2008 Lexus IS 350 require premium gas?

  Yes. The EPA lists the 2008 Lexus IS 350 as requiring premium gasoline. Running it on regular can reduce performance and may affect engine warranties, so it is not a recommended way to save at the pump.
• Has the Lexus IS 350 become more fuel efficient over time?

  Combined MPG has stayed close to flat across the run. Both the earliest (2006 Lexus IS 350, 21 MPG) and most recent (2026 Lexus IS 350, 22 MPG) versions sit in the same range.
• How much CO₂ does the 2008 Lexus IS 350 emit?

  Tailpipe CO₂ emissions are 444 g/mi. Multiplied across a typical year of driving (15,000 miles) that works out to about 6,665 kilograms of CO₂.
• What is the difference between the city and highway MPG of the 2008 Lexus IS 350?

  City driving returns 18 MPG and highway driving returns 25 MPG, a gap of 7 MPG. A spread that wide is typical of cars with conventional automatic or manual transmissions, where stop-start city traffic eats more fuel than a steady highway cruise.
• What engine is in the 2008 Lexus IS 350?

  The 2008 Lexus IS 350 has a 3.5-liter 6-cylinder engine.
• What transmission and drivetrain does the 2008 Lexus IS 350 have?

  The 2008 Lexus IS 350 comes with a automatic (s6) transmission and rear-wheel drive.
• How does the 2008 Lexus IS 350 compare to the best car in its class?

  The most efficient car in the Subcompact Cars class for the 2008 model year is the MINI Clubman at 32 combined MPG. The Lexus IS 350 returns 20 MPG, a gap of 12 MPG. If you are comparing on fuel economy alone, the class leader is worth a look.

Source: U.S. EPA fuel economy dataset. Annual fuel cost figures assume 15,000 miles of driving per year and a 55% city, 45% highway split. Real-world mileage varies with driving conditions, vehicle maintenance, fuel quality, and driver behaviour.