The mid-size Pontiac G6 comes in a dizzying array of configurations, with the most fuel-efficient combination delivering 30 miles per gallon (MPG) on the highway. Pontiac covers all the bases with the 2008 G6: sporty coupe, sleek four-door sedan, and snappy two-door convertible.

The Pontiac G6 Convertible is available with two different V6 engines, each mated to a four-speed electronically controlled automatic transmission:
- 3.5 liter V6, producing 217 horsepower (HP) and 217 foot pounds of torque. Gas mileage: 17 city / 26 highway.
- 3.9 liter V6, producing 222 HP and 238 foot pounds of torque. Gas mileage: 15 city / 22 highway.

The Pontiac G6 Coupe is available with two different V6 engines:
- 3.5 liter V6, producing 219 HP and 219 foot pounds of torque. Gas mileage: 17 city / 26 highway.
- 3.6 liter V6, producing 252 HP and 251 foot pounds of torque. Gas mileage: 17 city / 26 highway.
The G6 Coupe can be configured with the four- or six-speed electronically controlled automatic (with overdrive). The six-speed is standard on the GXP model. The G6 Convertible is a good bit heavier than the Coupe, with the GT Coupe weighing in at 3415 lbs., the GXP Coupe weighing in at 3487 lbs., and the Convertible tipping the scales at 3855 lbs.
The Pontiac G6 Sedan is available with three different engines and the choice of a four- or six-speed electronically controlled automatic transmission, with overdrive:
- 2.4 liter four cylinder engine, producing 169 HP and 162 foot pounds of torque. Gas mileage: 22 city / 30 highway.
- 3.5 liter V6, producing 217 HP and 217 foot pounds of torque. Gas mileage: 17 city / 26 highway.
- 3.6 liter V6, producing 252 HP and 251 foot pounds of torque. Gas mileage: 17 city / 26 highway.
Pontiac G6 Gas Mileage - 2005-2008
| Year | Manufacturer | Model | Engine | Disp. | Fuel | Trans. | City | Hwy |
| 2008 | Pontiac | G6 | 6 cylinder | 3.9 liter | R | (S4) Auto | 15 | 22 |
| 2008 | Pontiac | G6 | 6 cylinder | 3.6 liter | R | (S6) Auto | 17 | 26 |
| 2008 | Pontiac | G6 | 6 cylinder | 3.5 liter | R | (S4) Auto | 17 | 26 |
| 2008 | Pontiac | G6 | 6 cylinder | 3.5 liter | R | (L4) Auto | 18 | 29 |
| 2008 | Pontiac | G6 | 4 cylinder | 2.4 liter | R | (L4) Auto | 22 | 30 |
| 2007 | Pontiac | G6 | 4 cylinder | 2.4 liter | R | (L4) Auto | 23 | 33 |
| 2007 | Pontiac | G6 | 6 cylinder | 3.9 liter | R | (M6) Manual | 18 | 27 |
| 2007 | Pontiac | G6 | 6 cylinder | 3.5 liter | R | (L4) Auto | 20 | 30 |
| 2007 | Pontiac | G6 | 6 cylinder | 3.6 liter | R | (S6) Auto | 20 | 28 |
| 2007 | Pontiac | G6 | 6 cylinder | 3.5 liter | R | (S4) Auto | 20 | 28 |
| 2007 | Pontiac | G6 | 6 cylinder | 3.9 liter | R | (S4) Auto | 17 | 24 |
| 2006 | Pontiac | G6 | 4 cylinder | 2.4 liter | R | (L4) Auto | 23 | 34 |
| 2006 | Pontiac | G6 | 6 cylinder | 3.5 liter | R | (L4) Auto | 22 | 32 |
| 2006 | Pontiac | G6 | 6 cylinder | 3.9 liter | R | (M6) Manual | 18 | 29 |
| 2006 | Pontiac | G6 | 6 cylinder | 3.9 liter | R | (S4) Auto | 18 | 26 |
| 2006 | Pontiac | G6 | 6 cylinder | 3.5 liter | R | (S4) Auto | 21 | 29 |
| 2006 | Pontiac | G6 GT/GTP Convertible | 6 cylinder | 3.9 liter | R | (S4) Auto | 18 | 26 |
| 2006 | Pontiac | G6 GT/GTP Convertible | 6 cylinder | 3.5 liter | R | (S4) Auto | 19 | 27 |
| 2005 | Pontiac | G6 | 6 cylinder | 3.5 liter | R | (S4) Auto | 21 | 29 |
| 2005 | Pontiac | G6 | 6 cylinder | 3.5 liter | R | (L4) Auto | 22 | 32 |
Note: the EPA tweaked their testing procedure, starting with the 2008 model year, with the end result being that the 2008 MPG estimates are now lower than previous years. As always, YMMV.






5 comments ↓
im not sure if there is something wrong with my 08 g6 4 cyl. but i only get 22 on any drive. my driving which is to work and back is probably about 4 miles city and 35 miles highway in a round trip. i took it to my local dealership and they said there are no reprograms so there is nothing they can do.
@Megan - We haven’t had the chance to review the Pontiac G6 yet … but it’s on our short list for review in the coming months.
You might want to try a change in driving style. This can make a big difference in the amount of gas you use every day. If the G6 has an Instant (or “Real-Time”) MPG display, turn it on and leave it on. By watching the MPG numbers in real-time, you’ll learn how to drive for higher fuel-efficiency.
An Average (or cumulative) MPG display doesn’t provide that instantaneous feedback.
If your G6 does not have an Instant MPG display (I apologize that we haven’t had the chance to review the G6 yet), you can add an after market device to view this information. We’ve used the ScanGaugeII with great results:
http://www.mpgomatic.com/2008/07/07/improving-gas-mileage-with-the-scangaugeii-pt-1/
I have the same problem with my car. We took it to the dealer we brought it from, Southaven pontiac in Southaven, Miss. We had a hesitation just one time and an emission from the catalytic converter. They found no problems and no answer for 22 miles on a long trip. I am in no doubt at some time there will be a recall on some part of the car, but by then, will will have wasted all that gas. Kay Austin
My G6 only gets 22 mile a gallon on the highway…who do we see about the lie????
@Jennifer - which engine? what are your average highway speeds?
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