2023 Non-Turbo CX-5 all have CD!

Freedom55

2020 CX-5 GS AWD Montreal Canada
According to what I've read on their respective websites, both Canada and US versions will have cylinder deactivation on non turbo engines. Not sure if this applies to other models like CX-30, CX-50, 3 etc. IMO it would have been better to eliminate CD on all models.
 
CD = Cylinder Deactivation. CD stereos have already been declared obsolete and removed from models.
 
I don’t understand the apparent fear and loathing of CD. I’ve had that feature in three vehicles and found it pretty seamless and good for a few mpg. Of course, I have no experience with Mazda’s particular version.
 
I don’t understand the apparent fear and loathing of CD. I’ve had that feature in three vehicles and found it pretty seamless and good for a few mpg. Of course, I have no experience with Mazda’s particular version.
On this forum there are numerous posts about CD i.e. engine ticking, vibrations, broken engine parts, etc. but I don't have any problems with mine. It seems Mazda wants to simplify power train offerings as 2022 brought standard AWD on all trims and now CD on all non turbo trims. However for the past few years, there are more trims (Carbon or Kuro in Canada) with more wheel choices, leather seat colors and wheel arches finishes (black, glossy black and body color painted)!
 
It seems Mazda wants to simplify power train offerings as 2022 brought standard AWD on all trims and now CD on all non turbo trims. However for the past few years, there are more trims (Carbon or Kuro in Canada) with more wheel choices, leather seat colors and wheel arches finishes (black, glossy black and body color painted)!

Yes, it's probably just because the typical consumer cares more about aesthetics. They likely would not care if the car has CD or not (and may not even notice any engine ticking or vibrations).
 
I remember in the 80's, my manager had a special edition Cadillac with an 8-6-4 engine. I think that engine was a horrible failure.. possibly it caused some lingering bad sentiment towards the idea of dropping cylinders. I always thought it was a brilliant idea, but never knew why it wasn't done. I saw a documentary that examined the engineering difficulties around pulling it off (and why GM failed). It mostly had to do with relieving pressure in the dead cylinders. In today's engineering world, I would think those issues are easily solved. I am not a mechanic, I just find the idea to be very interesting.. I hope it turns out to be a good move.
 
The thing with the cx-5 is that it adds complexity for very little gain. Yes other manufacturers engines have done it with success. (Honda, GM, etc). But mazda has had some issues with it, and the benefits of turning a 4 cylinder in a two cylinder are not providing a lot of real world fuel economy (compared to turning a 8 cylinder or 6 cylinder into a 4 cylinder). The engine is too weak as a 2 cylinder to spend any reasonable amount of time in that configuration.

But as other have said, Mazda is trying to streamline it’s production chain i think, and to improve its mpg credits. From that stand point it may make more sense strategically for Mazda to only offer CD models.
 
I remember in the 80's, my manager had a special edition Cadillac with an 8-6-4 engine. I think that engine was a horrible failure.. possibly it caused some lingering bad sentiment towards the idea of dropping cylinders. I always thought it was a brilliant idea, but never knew why it wasn't done. I saw a documentary that examined the engineering difficulties around pulling it off (and why GM failed). It mostly had to do with relieving pressure in the dead cylinders. In today's engineering world, I would think those issues are easily solved. I am not a mechanic, I just find the idea to be very interesting.. I hope it turns out to be a good move.
Cylinder deactivation, or variable displacement, seems to be a good idea but only on paper. The major flaw of such idea is you can’t truly deactivate the entire cylinder all the way because the piston and crankshaft connected to those deactivated cylinders still have to move passively with friction which consumes energy. The air inside of the deactivated cylinders with both intake and exhaust valves closed also gets compressed and decompressed which also requires energy. Not to mention the thermal effect changes frequently due to frequent cylinder activation and deactivation, which adds problems for reliability on cylinders which can be deactivated. Even with today’s technology, Mazda simply can’t overcome these flaws inherent from the cylinder deactivation. With complicated CD system from Mazda which definitely would affect engine’s reliability (yes, many components had been redesigned, including the exhaust system) for only 0 ~ 1 EPA MPG gain on the CX-5, this’s simply a wrong move by Mazda IMO.

Nissan has developed a new cylinder deactivation system which will totally deactivated entire cylinder including piston and crankshaft. This system definitely makes sense to me. But the system is very complicated which may hurt the longevity of the engine, especially those problems from thermal issues.
 
... Even with today’s technology, Mazda simply can’t overcome these flaws inherent from the cylinder deactivation. With complicated CD system from Mazda which definitely would affect engine’s reliability (yes, many components had been redesigned, including the exhaust system) for only 0 ~ 1 EPA MPG gain on the CX-5, this’s simply a wrong move by Mazda IMO.

I'd be interested to know the developement / warantee cost trade-off vs. the economic benefits of that extra 1 MPG. It has to influence Mazda's overall EPA ratings given that is their most sold power plant in the US market.
 
Even with today’s technology, Mazda simply can’t overcome these flaws inherent from the cylinder deactivation.
Actually that's more a theory than practical application. I hate to sound like a broken record but Consumer Reports reliability ratings, based on owner reports from their four million members do not bear out your contention. Time will tell, but there is little evidence to support your claim.

In CR's engine-major category, all CX-5 years from 2019 forward have the highest rating. 2018 has been downgraded over time to average. That rating may be related to the CD rocker arm / stall recall, which the PCM update appears to have resolved. Or it could be turbo related since CR reliability ratings are aggregated across all trims for any particular model year. If the 2018 rating is related to the recall, then it is just another in a long list of cautionary tales regarding buying the first year of a model, generation or significant powertrain change regardless of who makes the vehicle.

That said, the TSB below raises some questions but since no specific problem is identified the mods to the cylinder head assembly could be for any number of reasons not related to longevity.

Back to CR, engine-minor ratings score the highest reliability rating for all years since 2018 except for 2019 which is down one notch to 4 out of 5.

Frankly, you'd be more likely to encounter problems with in-car electronics (endemic in the industry) or power equipment as the ratings in those categories yo-yo up and down over the years, or gen 1 brakes, or 2013 electrical systems.

There's probably 500,000+ CD engines on US roads. Perhaps more since Mazda does not break down sales by powertrain. Do we have to reiterate that anecdotal issue reports on a message board are not the best way to assess reliability? Only time will tell, not theories about a Mazda theory.

Frankly, I'd be concerned more about buying any new vehicle from anybody produced since the pandemic supply chain issues took hold. With the possibility of production line work flow being reorganized with part supply interruptions, "moving the cheese" in the assembly process opens up all kinds of potential assembly flaws.
 

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