Utility
The Chevrolet's more massive trunk will accommodate more sizeable objects than the Dodge Caliber.
The Caliber and the Chevrolet HHR can accommodate the same number of passengers.
Dimensions
The Dodge Caliber is a bit more ponderous than the Chevrolet HHR.
Your wallet will hurt more every time you fill up the Chevrolet HHR than the Dodge because of its more capacious tank.
The Dodge Caliber and the Chevrolet HHR compete for the same parking spaces.
Convenience
You'll definitely have to take the Dodge for a fill-up more often than the Chevrolet HHR because of its tank size and fuel economy.
Cost
The destination charge is a standard charge for transporting the vehicle from its point of origin to the dealer. It costs roughly the same to get the Dodge Caliber to the dealership as the HHR.
The Dodge Caliber pales in comparison to the Chevrolet HHR regarding gas mileage.
When it comes to MSRP, the Dodge Caliber costs roughly as much as the Chevrolet HHR (though the Chevrolet HHR is a bit cheaper).
Drivetrain
The HHR's engine is a little smaller than the Dodge's, but not terribly so.
The HHR has no lessons to learn in terms of torque from the Dodge Caliber.
Comfort
While the front cabin in the Dodge offers a bit more head room than the Chevrolet HHR, there honestly isn't much of a difference.
The HHR provides more head- and leg-room to your passengers than the Caliber does.
Overview
The Chevrolet HHR and the Dodge Caliber have the same basic after-sale protection.
When it comes to after-sale protection against corrosion, the Chevrolet has significantly better coverage than the Dodge Caliber.