Performance
With respect to horsepower, the Mazda MAZDA6 packs quite a punch and will knock the Honda Fit down a few rungs. However, keep in mind that high horsepower engines often command higher insurance premiums.
Both the Honda and the Mazda MAZDA6 are likely to feel slightly sluggish because of their high horsepower-to-weight ratio.
Handling
The MAZDA6 and the Fit have approximately similar tires.
With its tighter turning circle, the Honda Fit is very likely sprier than the Mazda MAZDA6, something to consider if you do a lot of city driving; on the flip side, keep in mind that a vehicle with a tight turning circle may feel a bit twitchy on the highway.
Drivetrain
The MAZDA6's engine is significantly bigger than the Honda Fit's. Note that larger engines may use more gas than smaller ones.
The Honda could learn a lesson or two from the Mazda regarding torque.
Utility
The Honda Fit and the Mazda can accommodate the same number of passengers.
Convenience
The Honda Fit's fuel tank will need to be replenished more often than the unit in the Mazda MAZDA6.
You'll doubtless have to take the Fit for a fill-up more often than the Mazda MAZDA6 because of its tank size and fuel economy.
Comfort
Taller drivers will quite a bit enjoy the extra head room in the Honda Fit's front cabin compared to the Mazda MAZDA6.
While the rear of the Mazda MAZDA6 provides a bit more head- and leg-room than the Honda Fit, there frankly isn't much of a difference.
Dimensions
The Mazda is substantially heavier than the Honda.
Your wallet will hurt more every time you fill up the Mazda MAZDA6 than the Honda Fit because of its bigger tank.
The Honda Fit fits in smaller parking spaces than the MAZDA6.
The Fit's shorter wheelbase will likely give a more maneuverable feel in daily traffic. However, the Mazda MAZDA6 is likely to have a smoother, more stable ride.
Cost
The MAZDA6 consumes a lot of gas compared to the Honda.
In terms of fuel economy, the Fit bests the Mazda MAZDA6.
The Mazda is tremendously costlier than the Honda Fit as far as MSRP.
In terms of purchase price, the Mazda costs tremendously more than the Honda Fit.
The Mazda MAZDA6 will cost you a bundle in gasoline every year compared to the Honda Fit.
The Fit will save you a bundle at the pump every year compared to the MAZDA6.
Overview
The Mazda MAZDA6 and the Honda Fit have the same basic warranty.