HP difference between 2.5 NA CX-5 and CX-30
- Thread starter zx10guy
- Start date
I know. I'm not looking to chase small HP increases nor am I looking to modify my car to get more horsepower. Being the engines are the same between the two chassis, I was just wondering why the difference. It's just an academic query. Is it due to intake plumbing/routing? I also noticed that the engines in the CX-5 with cylinder deactivation are showing 1ft lb less in torque than the non CD engines. Just interesting to see the variations.
I checked the 2026 models and saw that the CX-30 had 1 less HP (186 vs 187) than the CX-5.
That's the most HP I've ever heard of out of a NA 2.5L Mazda. Was it a sport/performance model or something special edition?
Here's a dealer website I found doing a search for the 2025 CX-30 specs:
And it shows 191HP for the S trim.
2025 Mazda CX-30 Specs, Price, Colors | Tim Dahle Mazda Murray
2025 Mazda CX-30 Specs, Price, Colors | Tim Dahle Mazda Murray
www.timdahlemazdamurray.com
And it shows 191HP for the S trim.
My guess would be different tuning maps for emission reasons. The CX 30 is lighter then the CX 5 so maybe they could tune it for more HP with same emission results?
The loss of 5 HP for the 2026 CX 30 could be because of the same reason: lowering emission ratings.
The loss of 5 HP for the 2026 CX 30 could be because of the same reason: lowering emission ratings.
Good question—and you’re right to look at it as an academic/engineering curiosity rather than a performance chase.
Even when engines are “the same,” small differences in ratings usually come from supporting hardware and calibration, not the core engine itself. Things like intake routing, exhaust layout, and even engine bay packaging can change airflow slightly. Different chassis mean different space constraints, heat management, and noise/emissions tuning, which all affect how the engine is mapped.
As for cylinder deactivation showing 1 ft-lb less torque, that’s almost certainly a tuning choice. CD systems require different cam profiles, valve control strategies, and ECU mapping to allow smooth transitions between modes. To keep drivability, reliability, and emissions consistent, manufacturers often sacrifice a tiny bit of peak output—even if it’s so small it’s basically irrelevant in real-world driving.
I do think there's some tuning stuff going on. I saw a video discussing Mazda in the Australian market and how Mazda is going to be in trouble meeting the emissions requirements. There was a mention about detuning the 2.5NA in the CX-5 down to 177HP.
I guess the tuning choices being made may also be influenced by global factors. Still interesting seeing the CX-30 being detuned for the 2026 model year for the US and I wonder why the CX-5 for the US wasn't brought up to parity with the CX-30.
The other odd thing about the CX-5 2.5NA with iStop/CD is it appears the 2026 model year cars gained back that lost 1 lb ft of torque.
I guess the tuning choices being made may also be influenced by global factors. Still interesting seeing the CX-30 being detuned for the 2026 model year for the US and I wonder why the CX-5 for the US wasn't brought up to parity with the CX-30.
The other odd thing about the CX-5 2.5NA with iStop/CD is it appears the 2026 model year cars gained back that lost 1 lb ft of torque.
Europe (or anywhere) has better quality gasoline than NA?!
The 191hp version in North America was used in the 3 and CX-30 from 23-25 model years. The engine has an egr valve, traditional thermostat, cylinder deactivation, redesigned intake ports, different exhaust manifold to support egr, different intake manifold with fatter runner cross section as well as tumble inducing flaps and a different exhaust camshaft. A different tune of course to handle all of the hardware changes, it also to me driven back to back has a noticeable bump in low speed torque.
