Handling
The HUMMER H3 has markedly bigger tires than the Acura RDX. Keep in mind that bigger tires could improve handling, while narrower tires may provide better handling in deep snow.
With their comparable turning radii, the HUMMER and the Acura RDX most definitely handle roughly the same into and out of tight spots.
Drivetrain
The HUMMER H3 has a larger engine than the Acura. Keep in mind that smaller engines are often cheaper to fix, but a smaller engine usually has to work a little harder.
The H3 has no lessons to learn in terms of torque from the Acura RDX.
Utility
There's no clear winner between the Acura RDX and the HUMMER as far as transporting cargo.
The HUMMER and the RDX can accommodate the same number of passengers.
The HUMMER H3 outpulls the Acura RDX by a massive margin.
Convenience
The Acura RDX's fuel tank will need to be replenished a little more often than the unit in the H3.
Comfort
Taller drivers will substantially enjoy the extra head room in the HUMMER H3's front cabin compared to the Acura RDX.
While the rear of the Acura offers a bit more head- and leg-room than the HUMMER H3, there really isn't much of a difference.
Dimensions
The H3 is quite a bit heavier than the Acura.
Your wallet will hurt more every time you fill up the H3 than the Acura RDX because of its more capacious tank.
The HUMMER H3 rides lower than the Acura RDX, which is a good thing for its center of gravity and ease of access.
The RDX and the HUMMER compete for the same parking spaces.
The Acura's shorter wheelbase will likely give a more agile feel in daily traffic. On the flip side, the HUMMER is likely to have a smoother, more stable ride.
Cost
The destination charge is a standard charge for transporting the vehicle from its point of origin to the dealer. It costs approximately the same to get the HUMMER H3 to the dealership as the Acura RDX.
The Acura RDX will save you money at the pump compared to the HUMMER H3.
With respect to gas mileage, the Acura RDX beats the H3.
The Acura RDX isn't much less expensive than the HUMMER H3 with respect to MSRP.
Overview
The Acura and the H3 have the same basic after-sale protection.