^^^easiest way to tell...look at the button cluster to the left of the steering wheel to see if the button is present...since it's not listed on the window sticker like the cylinder deactivation feature seems to be

2025 cx-5 manual

 

Yes its there / flanked by the parking distance warning and / LDW - but its accessible thru infotainment as well -- as is LDW -redundancy --If you think about it these systems must have a secondary pathway - if infotainment goes out -- then engine and safety management systems are not able to be altered- heres a challenge -- try to find the engine oil filter specifications / number in the manual --nowhere --- Mazda parts person said most people never open the owners manual - Thanks for the help

 

Sorry to resurrect the thread but I think this is a really interesting topic worthy of more chat.

I am a brand new Mazda owner and new to the forum. Like man- I suspect- I didn't catch the significance of CD until after purchase. Yeah, I should have done more homework. Yeah I am pissed at myself because this kind of detail IS in my wheelhouse. As it happened I was buying mainly for my wife daughter and late in the negotiations she really wanted the sunroof and real leather... and so the deal for a Preferred was signed without me noticing CD was on the car. Or really researching it. My fault. But frankly, even if I had been at full awareness I am not sure what the decision would have been
since otherwise this car is darn near perfect for its purpose.

So now that the car is ours, I I am starting the breakin- 100 miles so far- with focus ion getting as long a life from the vehicle as possible.

Digging into it CD actually has several modifications:

- a unique valve assembly (shown in Mazda video) to close the intakes
- a modified torque converter
- exhaust valve that opens or closes to mask the sound
- programming differences in ECM

Cons
-potential impacts on long term reliablity (several failure modes, leaks, uneven wear, transmission)
-possible impact on ride quality (small shudders, jolts, changes to engine note... some say yes, some say no)

Pros
- it seems that this tech actually does save meaningful gas... at least 1MPG, but maybe more... considerably more than the trivial amount that IStop saves

So my plan?

Clearly more reason to do frequent oil changes... and to add transmission drain fill at 30k instead of 60k perhaps. Use top tier gas ( perhaps 89 octane).

And in that spirit I have questions for the forum:

1 - Does CD favor staying with the base reco 0W20 oil? Or is a move to 5W30 helpful (considering that odds are likely 5W30 is a good for the NA engine in general over a very long span unless living in super cold areas). Or is this system actually going to work better with low visc. oil?

2 - For you owners with high miles and CD ... does it tend to require more frequent valve cleaning or spark plug intervals (because the middle two cylinders get more usage than the outer)? So instead of 75m reco, 50 or 60k?

In general also more digging into the actual fuel savings is interesting. I'd like to think there is at least SOME benefit... do my bit once breakin is over to report milage.

Overall my thoughts are that for Mazda to have brought CD back on 2025 top trims means they had to have had some combination of confidence (that the kinks are worked out) and /or desperation (because at the time they still needed to hit CAFE target).

And it is perhaps disheartening - unless one is a 2026 buyer- to see CD is gone from the entire 2026 lineup. Perhaps they found more issues? OR perhaps simply cost/benefit equation has changed due to relaxation of CAFE? CD must have a real cost to Mazda- its not just programming, it's hardware.

Thoughts? Thanks all and nice to meet you.

 

Congrats on the new car! The simple answer I have to what you wrote is to use the oil in your manual from Mazda and you're fine doing the plugs at the intervals inthe manual. The plugs are actually able to get 100k+ miles, but the 70k-75k marker is good to follow and it's super easy to do in 20 minutes. The cylinder deactivation in these cars is by far one of the best and smoothest. I'm someone who doesn't like having it on my cars, but it's been great on our non-turbo CX-5.

 

Thanks. Yeah I'm both annoyed that I have this and that it ks not defeat-able, bit also kind of impressed with it. The gas savings is compelling.

So far I can feel the CD difference but really only if I watch the fuel monitor and use it to learn the faint "tells" of the 2 modes interacting with the gas pedal. Not imperceptible but not obvious either. Weirdly, at 65mph straight and level I'd almost sag the car cruise slightly quieter in 2 cyl mode. At least for now, at 200 miles and avoiding steady cruise for breaking.

I want to keep digging on this tech from an open minded perspective. Mazda must have worked hard on this and put quite a lot of cars on the road with the CD since 2018. Even if 2025 is the last year of its implementation, it had an 8 year run. Some teething pains in early years with timing cover leaks and torque converters... but these seem to have been addressed with mods and warranty programs.

Does anyone know if CD is still offered in Canada or Europe for 2026? Other markets? Or is 2026 a worldwide sunset for this CD powertrain?

 

They're still carryying it over to 2026 models here in the U.S. as far as I'm aware.

 

my question is when does mazda catch on and add port fuel injection back to clean valves of carbon buildup like other manufacturers have done to remedy this issue with gdi engines...toyota/lexus, ford, vw, mercedes, honda/acura and bmw/mini done this...even kia/hyundai/genesis are starting to do it with the newer smartstream engines

 

The dual port/direct injection options Ford and Toyota have moved to - I think Toyota calls it D4S - hasn't been a miracle. I know 2 owners if the RAV4 that have had injector replacement at only 70,000 miles. I haven't read of any significant issues with Mazda's current direct injection design where someone that used quality fuel (Top Tier like Chevron or Shell) and quality GF-6A or 7 oil and had carbon so bad on valves it affected performance. Of course there may be a few reports on the internet just like there are reports of human women birthing camels. It's a worry without a reason.

 

Before SkyActive Mazda had the L/MZR engine, aka the Ford Duramax 2.5 L, as the precursor. Port injected.

This engine was in the Mazda 6. But in my kid's 2018 Ford Fusion. Love it. It's a great engine on the highway, and built like a tank. But at least in Ford applications, is *not* zoomy or satisfying to drive around town in a mid sized car.

HP and torque specs are close between the MZR and Skyactive- not miles off in performance in theory. But sounds different. Maybe builds torque different?

Certainly SkyActive was much more fuel efficient. The Mazda 6 went from 22/31 mpg in 2012 with the MZR 2.5L to 26/38 in 2014 with the SkyActive G, then 26/35 by 2018 with CD and 2 refresh cycles that probably added some weight to the vehicle.

Its still not clear just how much fuel the CD itself saves... but there is no doubt the SkyActive powertrain overall makes the driving experience better and saved a good chunk of gas vs the stalwart port injection precursor Mazda engine.

I wonder if CD was part of why Mazda went DI in the first place? Doesnt DI make it easier to have a robust CD system incorporated ? All part of the plan" of the original SkyActive suite as they say?

 

Back to topic:

Here are two Mazda technical publications from 2017/18 about CD. In Japanese but your PDF reader can probably translate.


2017_no007.pdf


2018_no003.pdf

Quite a bit of engineering indeed.