2009 Porsche Boxster S: MPG and fuel economy

This page collects every fuel-economy figure the EPA publishes for the 2009 Porsche Boxster S. 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 2 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 Porsche Boxster S. 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 2 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 Porsche Boxster S compares

The 2009 Porsche Boxster S returns 23 combined MPG. Cars in the Two Seaters class for the same model year average 18.9 MPG, which puts this car ahead of the class average by about 22%.

The most efficient car in the Two Seaters class for the 2009 model year is the smart fortwo convertible at 36 MPG. The bar chart below puts the Porsche Boxster S 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 2 separate variants of the 2009 Porsche Boxster S. 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.

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 652.2 gallons (the car's annual consumption at the rated MPG).

Year-over-year MPG for the Porsche Boxster S

The EPA has rated the Porsche Boxster S across 21 model years, from 2000 Porsche Boxster S through 2020 Porsche Boxster S. 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 2013 Porsche Boxster S at 24 MPG.

Compare against other Two Seaters for 2009

If you are cross-shopping the 2009 Porsche Boxster S, the most useful comparison is against the other cars in the Two Seaters 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 smart fortwo convertible leads this group at 36 MPG, 13 MPG ahead of the 2009 Porsche Boxster S.

Specifications

The 2009 Porsche Boxster S runs a 3.4-liter 6-cylinder engine paired with a automatic 7-spd, 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

Two Seaters

Engine

3.4L 6-cylinder

Transmission

Automatic 7-spd

Drivetrain

Rear-Wheel Drive

Fuel type

Premium

Annual petroleum use

12.9 barrels per year

Common questions about the 2009 Porsche Boxster S

Quick answers to the questions people most often search for when looking up the 2009 Porsche Boxster S.

• Is the 2009 Porsche Boxster S fuel efficient?

  Yes. The 2009 Porsche Boxster S returns 23 combined MPG, which beats the average car in the Two Seaters class for the same model year by about 22%.
• What MPG does the 2009 Porsche Boxster S get?

  The EPA rates the 2009 Porsche Boxster S at 23 combined MPG, 20 MPG in city driving, and 29 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 Porsche Boxster S per year?

  The EPA estimates an annual fuel cost of $3,000 for the 2009 Porsche Boxster S. 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 2009 Porsche Boxster S require premium gas?

  Yes. The EPA lists the 2009 Porsche Boxster S 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 Porsche Boxster S become more fuel efficient over time?

  Combined MPG has stayed close to flat across the run. Both the earliest (2000 Porsche Boxster S, 18 MPG) and most recent (2020 Porsche Boxster S, 22 MPG) versions sit in the same range.
• How much CO₂ does the 2009 Porsche Boxster S emit?

  Tailpipe CO₂ emissions are 386 g/mi. Multiplied across a typical year of driving (15,000 miles) that works out to about 5,796 kilograms of CO₂.
• What is the difference between the city and highway MPG of the 2009 Porsche Boxster S?

  City driving returns 20 MPG and highway driving returns 29 MPG, a gap of 9 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 Porsche Boxster S?

  The 2009 Porsche Boxster S has a 3.4-liter 6-cylinder engine.
• What transmission and drivetrain does the 2009 Porsche Boxster S have?

  The 2009 Porsche Boxster S comes with a automatic 7-spd transmission and rear-wheel drive.
• How does the 2009 Porsche Boxster S compare to the best car in its class?

  The most efficient car in the Two Seaters class for the 2009 model year is the smart fortwo convertible at 36 combined MPG. The Porsche Boxster S returns 23 MPG, a gap of 13 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.