Utility
The Mazda MAZDA6 and the G6 can accommodate the same number of passengers.
Performance
In terms of horsepower, the Pontiac G6 packs quite a punch and will knock the Mazda MAZDA6 down a few rungs. On the flip side, note that high horsepower engines often command higher insurance premiums.
Dimensions
Your wallet will hurt more every time you fill up the Mazda than the Pontiac G6 because of its bigger tank.
The Pontiac G6 and the Mazda MAZDA6 compete for the same parking spaces.
Cost
The destination charge is a standard charge for transporting the vehicle from its point of origin to the dealer. It costs about the same to get the Pontiac G6 to the dealership as the Mazda.
The Pontiac G6 isn't much costlier than the Mazda MAZDA6 as far as MSRP.
Handling
With their similar turning radii, the MAZDA6 and the Pontiac G6 most certainly handle approximately the same into and out of tight spots.
Drivetrain
The Pontiac and the Mazda MAZDA6 have similar-sized engines, with a slight advantage to the Mazda MAZDA6.
Torque is roughly equivalent to acceleration, and in this respect, the Mazda MAZDA6 isn't much more powerful than the Pontiac G6.
Comfort
While the front cabin in the Mazda MAZDA6 offers a bit more head room than the Pontiac G6, there really isn't much of a difference.
While the rear of the MAZDA6 provides a bit more head- and leg-room than the Pontiac G6, there honestly isn't much of a difference.
Warranty
The Pontiac G6 and the Mazda MAZDA6 have the same basic warranty.