Handling
With their similar turning circles, the G5 and the Pontiac Vibe likely handle almost the same into and out of tight spots.
Drivetrain
The Pontiac G5 has a more sizeable engine than the Pontiac Vibe. Keep in mind that smaller engines typically get better gas mileage, but a smaller engine usually has to work a little harder.
Torque equals pickup, and the Pontiac G5 will have picked up and gone by the time the Pontiac Vibe finally gets moving.
Torque is the force that lets you accelerate quickly, and in this respect, the Pontiac G5 is substantially more powerful than the Vibe.
Utility
Neither the Vibe nor the Pontiac G5 has a marked advantage as far as seating capacity.
The Pontiac Vibe outpulls the Pontiac G5 by a massive margin.
Convenience
The Pontiac Vibe's fuel tank will need to be replenished more often than the unit in the Pontiac G5.
Comfort
Taller drivers will significantly enjoy the extra head room in the Pontiac Vibe's front cabin compared to the Pontiac G5.
The Pontiac Vibe offers more head- and leg-room to your passengers than the G5 does.
Dimensions
The Pontiac Vibe and the Pontiac G5 compete for the same parking spaces.
Cost
The Vibe will tax your gasoline budget significantly more than the G5 will.
Regarding fuel economy, the Pontiac G5 has the Pontiac Vibe beat.
The Pontiac G5 isn't much pricier than the Pontiac Vibe in terms of MSRP.
The Pontiac Vibe will cost you a bundle in gas every year compared to the G5.
The Pontiac G5 will save you a lots_of_money at the pump every year compared to the Pontiac Vibe.
Warranty
The G5 and the Vibe have the same basic warranty.