2009 Pontiac G8: MPG and fuel economy

This page collects every fuel-economy figure the EPA publishes for the 2009 Pontiac G8. 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. The EPA rates 4 separate variants of this car (different engine, transmission, or drivetrain combinations), and you can compare them side by side in the trims table. 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 2009 Pontiac G8. 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.

When the EPA tests several variants of the same nameplate (for example, a front-wheel-drive version and an all-wheel-drive version), each gets its own rating. The figures shown here are the headline variant, taken as the configuration with the best combined MPG. The trims table further down covers all 4 variants side by side.

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 2009 Pontiac G8 compares

The 2009 Pontiac G8 returns 20 combined MPG. Cars in the Large Cars class for the same model year average 17.4 MPG, which puts this car ahead of the class average by about 15%.

The most efficient car in the Large Cars class for the 2009 model year is the Honda Accord at 25 MPG. The bar chart below puts the Pontiac G8 alongside the class best and the class average so you can see the full picture.

For broader context, the average new car of the 2009 model year (across all classes) returns 19.5 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 2009 model year is on its own page.

Trim variants rated for 2009

The EPA rates 4 separate variants of the 2009 Pontiac G8. The differences come from the engine size, transmission type, and drivetrain (front-wheel drive, all-wheel drive, and so on). The same nameplate can land several MPG apart depending on the configuration you actually buy.

The most efficient configuration on this page returns 20 MPG, while the least efficient returns 15 MPG. That is a spread of 5 MPG between trims of the same nameplate.

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 regular gasoline, which is $3.99/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 Pontiac G8

The EPA has rated the Pontiac G8 across 2 model years, from 2008 Pontiac G8 through 2009 Pontiac G8. 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, hovering close to 20 MPG.

Compare against other Large Cars for 2009

If you are cross-shopping the 2009 Pontiac G8, the most useful comparison is against the other cars in the Large 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 Honda Accord leads this group at 25 MPG, 5 MPG ahead of the 2009 Pontiac G8.

Specifications

The 2009 Pontiac G8 runs a 3.6-liter 6-cylinder engine paired with a automatic (s5), 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

Large Cars

Engine

3.6L 6-cylinder

Transmission

Automatic (S5)

Drivetrain

Rear-Wheel Drive

Fuel type

Regular

Annual petroleum use

14.9 barrels per year

Common questions about the 2009 Pontiac G8

Quick answers to the questions people most often search for when looking up the 2009 Pontiac G8.

• Is the 2009 Pontiac G8 fuel efficient?

  Yes. The 2009 Pontiac G8 returns 20 combined MPG, which beats the average car in the Large Cars class for the same model year by about 15%.
• What MPG does the 2009 Pontiac G8 get?

  The EPA rates the 2009 Pontiac G8 at 20 combined MPG, 17 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 2009 Pontiac G8 per year?

  The EPA estimates an annual fuel cost of $3,000 for the 2009 Pontiac G8. 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.
• What fuel does the 2009 Pontiac G8 use?

  The EPA lists the 2009 Pontiac G8 as running on regular gasoline. Using a different grade than the manufacturer specifies can affect fuel economy and engine longevity.
• How much CO₂ does the 2009 Pontiac G8 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 2009 Pontiac G8?

  City driving returns 17 MPG and highway driving returns 25 MPG, a gap of 8 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 2009 Pontiac G8?

  The 2009 Pontiac G8 has a 3.6-liter 6-cylinder engine.
• What transmission and drivetrain does the 2009 Pontiac G8 have?

  The 2009 Pontiac G8 comes with a automatic (s5) transmission and rear-wheel drive.
• How does the 2009 Pontiac G8 compare to the best car in its class?

  The most efficient car in the Large Cars class for the 2009 model year is the Honda Accord at 25 combined MPG. The Pontiac G8 returns 20 MPG, a gap of 5 MPG. If you are comparing on fuel economy alone, the class leader is worth a look.
• How much more does the 2009 Pontiac G8 cost in fuel compared to an average car?

  The EPA estimates that over five years, the 2009 Pontiac G8 will cost about $4,250 more in fuel than an average new vehicle of the same model year. The difference accumulates because the car uses more fuel per mile, not because of any one-off charge at the dealership.

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.