RDX vs QX55
It’s Acura against Infiniti in the compact luxury suv class, and the RDX and the QX55 are the models carrying each flag. Surprisingly little separates them. A handful of specs move the needle; the rest are rounding errors.
At a glance
- Engine & Performance Tie
- Space & Practicality RDX wins
- Off-road & Towing Tie
- Engine & Performance4.4
- Space & Practicality7.8
- Engine & Performance4.2
- Space & Practicality5.5
Spec scores (0 to 10) are calculated from manufacturer specs against other models in the same class. See how the formula works. They are not reviews or user ratings.
Key Differences
-
The RDX has 9.7% more cargo space
Only a little separates them: 29.5 cu ft on the RDX, 26.9 cu ft on the QX55. Cargo space behind the rear seats is what you use every day for groceries, strollers and luggage.
-
The RDX has 8.9% more maximum cargo space
It’s a fine margin, and it favors the RDX (58.9 cu ft versus 54.1 cu ft). The RDX can swallow more with the seats down, which makes it more versatile for occasional big loads.
Design & Size
Dimensions
| Spec | RDX | QX55 |
|---|---|---|
| Length | N/A (not specified) | 186.3 in |
| Width (no mirrors) | N/A (not specified) | 74.9 in |
| Wheelbase | N/A (not specified) | 110.2 in |
Engine & Performance
Too close to call
Both the RDX and the QX55 cover engine & performance equally well on paper. So engine & performance is a non-factor here; move on to the areas where they actually differ.
Space & Practicality
RDX leads
The RDX clearly takes the space & practicality round. The RDX adds 9.7% more cargo space. Cargo figures are measured in different ways by different makers, so small gaps may not show in practice. Prioritize space & practicality, and the RDX is where you should land.
Cargo (behind rear seats)
RDX: 29.5 cu ft QX55: 26.9 cu ft The RDX’s larger cargo area makes family trips and big shopping runs easier.
Cargo (seats folded)
RDX: 58.9 cu ft QX55: 54.1 cu ft Check the shape of the load floor too: a flat floor can matter as much as the number.
Off-road & Towing
Too close to call
The off-road & towing specs are close enough that neither gets the point. For off-road & towing, pick whichever you prefer for other reasons.
Safety & Tech
The safety & tech entries below are descriptive rather than numeric. Read them side by side to see where the RDX and the QX55 part ways.
Full Specifications
Engine & Performance
| Spec | RDX | QX55 |
|---|---|---|
| Powertrain | Gas | Gas |
| Engine | 2.0L turbo I4 | 2.0L turbo I4 (VC-Turbo) |
| Total system output | 272 hp | 268 hp |
| Torque | 280 lb-ft | 280 lb-ft |
| Transmission | 10-speed automatic | CVT |
| Drivetrain | N/A (not specified) | AWD |
Fuel Economy & Range
| Spec | RDX | QX55 |
|---|---|---|
| Fuel economy (combined)EPA estimate where available | N/A (not specified) | 25 mpg |
| Fuel economy (city) | N/A (not specified) | 22 mpg |
| Fuel economy (highway) | N/A (not specified) | 28 mpg |
Space & Practicality
| Spec | RDX | QX55 |
|---|---|---|
| Seats | 5 seats | 5 seats |
| Cargo (behind rear seats) | 29.5 cu ft (winner) | 26.9 cu ft |
| Cargo (seats folded) | 58.9 cu ft (winner) | 54.1 cu ft |
Off-road & Towing
| Spec | RDX | QX55 |
|---|---|---|
| AWD / 4WD available | Yes | Yes |
Safety & Tech
| Spec | RDX | QX55 |
|---|---|---|
| Basic warranty | 4 yr / 50,000 mi | 4 yr / 60,000 mi |
Dimensions
| Spec | RDX | QX55 |
|---|---|---|
| Length | N/A (not specified) | 186.3 in |
| Width (no mirrors) | N/A (not specified) | 74.9 in |
| Wheelbase | N/A (not specified) | 110.2 in |
“N/A” means the manufacturer does not specify the value or we could not confirm it. Figures marked “manufacturer rating” are the maker’s own claims, not our measurements.
Which One Should You Buy?
Choose the RDX if…
- you haul strollers, luggage or sports gear every week (29.5 cu ft vs 26.9 cu ft)
- you move bulky items now and then (58.9 cu ft vs 54.1 cu ft maximum cargo)
- you’re loyal to Acura and happy with it
Also Compared
Frequently Asked Questions
Which is better for most people, the RDX or the QX55?
On the specs compared here, the RDX makes more sense for most buyers; the QX55 doesn’t win a single measurable area.
Executive Summary
Acura or Infiniti? For a lot of people, the question really comes down to the RDX versus the QX55. Here’s what matters most to me: the RDX offers 9.7% more cargo space.
Who should get which? The RDX for space & practicality, the QX55 for the things a spec sheet can’t capture.
My pick: the RDX.
Personal opinion based on the data above. Your priorities may differ.