Cylinder Deactivation Update

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2010 CX-9 GT
But the deactivated cylinders are still pumping, compressing and decompressing the same air, right?

Yes. They keep the valves closed and the piston compresses the air and then the compressed air pushes the piston back down. They do this to avoid cooling the deactivated cylinders too much which would create big temperature gradients across the engine. Also, keeping the valves closed eliminates pumping losses.
 
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Based on the posts here, it sounds like the software update has solved the rocker arm issue? Any new 2020 CX-5 should have the latest software, right? We are looking at a new CX-5 Touring (no budget for turbo) and after driving every conceivable vehicle in the segment, it's down to this or a Forester. The Forester has issues with spontaneous windshield breakage, some people with only 150 miles. Subaru is taking no responsibility and says they hit a rock. I don't want to pay my deductible every time the windshield has a defect and the camera system needs a recalibration. I like that Mazda has taken ownership and supplied a solution. Would be nice if the new head design could be installed on all cars, or warranty is extended to cover it.
 
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Texas
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'19 MX-5, '20 CX-5
We are looking at a new CX-5 Touring (no budget for turbo) and after driving every conceivable vehicle in the segment, it's down to this or a Forester.

If $140 more per month on a 5-year auto loan (the difference between a Touring and Grand Touring Reserve) introduces a financial hardship, I can't help but wonder if either purchase would be wise at this time. Do you need a new vehicle?
 
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2018 CX-5 Sport
If $140 more per month on a 5-year auto loan (the difference between a Touring and Grand Touring Reserve) introduces a financial hardship, I can't help but wonder if either purchase would be wise at this time. Do you need a new vehicle?
$8,400 is a lot of money to most people.
 
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2018 CX-5 Sport
Based on the posts here, it sounds like the software update has solved the rocker arm issue? Any new 2020 CX-5 should have the latest software, right? We are looking at a new CX-5 Touring (no budget for turbo) and after driving every conceivable vehicle in the segment, it's down to this or a Forester. The Forester has issues with spontaneous windshield breakage, some people with only 150 miles. Subaru is taking no responsibility and says they hit a rock. I don't want to pay my deductible every time the windshield has a defect and the camera system needs a recalibration. I like that Mazda has taken ownership and supplied a solution. Would be nice if the new head design could be installed on all cars, or warranty is extended to cover it.
The head wasn't redesigned.
 
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2013 Mazda CX-5 Sport FWD Auto
If $140 more per month on a 5-year auto loan (the difference between a Touring and Grand Touring Reserve) introduces a financial hardship, I can't help but wonder if either purchase would be wise at this time. Do you need a new vehicle?
$140 is a lot of dough per month. You don’t know what folks have money earmarked for, thus not a helpful post at all. $140 a month for a turbo, or $140 a month towards a child’s college savings? As the poster suggested it’s called a budget.

I haven’t heard of any issues after the software update. I personally think the Mazda would be more reliable but I don’t have hard data to back up that opinion.
 
Also, I don't know if anyone has struggled with this. But for a year I had terrible vibrations from being in two cylinder mode. Sometimes it would shake the car at 90 kmh while dropping to two cylinders(Constantly not just when switching) It also produced a low pitched rumbling sound along with the vibration. Just recently a TSB was released to try and resolve this issue. It's helped alot, but I can still feel it at certain speeds. It's smooth as ever in 4 cylinders. I wish I didn't have this junk in my car. I know there has been a number of us that have had the issue on the Mazda Revolution forum as well as on the CX-30 Forum USA and Germany.

 
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Also, I don't know if anyone has struggled with this. But for a year I had terrible vibrations from being in two cylinder mode. Sometimes it would shake the car at 90 kmh while dropping to two cylinders(Constantly not just when switching) It also produced a low pitched rumbling sound along with the vibration. Just recently a TSB was released to try and resolve this issue. It's helped alot, but I can still feel it at certain speeds. It's smooth as ever in 4 cylinders. I wish I didn't have this junk in my car. I know there has been a number of us that have had the issue on the Mazda Revolution forum as well as on the CX-30 Forum USA and Germany.


seems to be for the 7th generation systems.i.e cx30 and the new 3
not sure it would do anything on cx5 as only 2021 is 7th generation.
 
seems to be for the 7th generation systems.i.e cx30 and the new 3
not sure it would do anything on cx5 as only 2021 is 7th generation.
Oops. I forgot the OP had a 2018 cx5. Regardless the cylinder head TSB is for all of them I think. They just should not have put this in any of them in my opinion
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
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Plano, Texas, USA
yes, we all agree to this. its complication with little benefit.
By comparison, 2020 Toyota RAV4 with 2.5L has better MPG (see EPA comparison)、more horsepower (203 hp vs. 187 hp) without use anything like cylinder deactivation that CX-5 2.5L uses

DD8C5835-1F90-476D-BC85-C0D703C7D1D3.jpeg
 
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Texas
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'19 MX-5, '20 CX-5
It would be interesting to see the CX-5's fuel economy rating if it gained two gears and lost 180 lbs. like the RAV4.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
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Plano, Texas, USA
It would be interesting to see the CX-5's fuel economy rating if it gained two gears and lost 180 lbs. like the RAV4.
And the thermal efficiency from the engine. Toyota’s Dynamic Force 2.5L has 40% / 41% (hybrid) thermal efficiency which is the industry best for mass-production engines.
 
yes, we all agree to this. its complication with little benefit.
Also it appears Mazda is slowly pulling this tech out of the cars. At least they pulled it for the 2021 CX-30 as well as all 2021 Mazda 3's in Canada. In the USA they pulled it from CX-30 and left it only on the very top trim(Non-Turbo) Mazda 3 and possibly CX-5. Let's hope that is the case, I think the EPA number "Difference" is only like 0.4 litres/100km. Not worth the struggle here.

I mean they almost lost me as a customer as I almost traded mine in as they couldn't fix the vibration for over a year(And I am not alone) I am long time purchaser of Mazda vehicles (Dating back to a 1990 Miata) This was a case of me not doing proper research on the technology and trusting Mazda 100 percent as usually the cars they make are stellar(And it is stellar, without this tech!)
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Also it appears Mazda is slowly pulling this tech out of the cars. At least they pulled it for the 2021 CX-30 as well as all 2021 Mazda 3's in Canada. In the USA they pulled it from CX-30 and left it only on the very top trim(Non-Turbo) Mazda 3 and possibly CX-5. Let's hope that is the case, I think the EPA number "Difference" is only like 0.4 litres/100km. Not worth the struggle here.
I sure hope Mazda can admit their mistake by using historically problematic cylinder deactivation with concept flaws, and quickly remove this feature from the lineups.

BTW, the improvement on US EPA fuel economy ratings for CX-5 with CD is 0~1 mpg.

I mean they almost lost me as a customer as I almost traded mine in as they couldn't fix the vibration for over a year(And I am not alone) I am long time purchaser of Mazda vehicles (Dating back to a 1990 Miata) This was a case of me not doing proper research on the technology and trusting Mazda 100 percent as usually the cars they make are stellar(And it is stellar, without this tech!)
Well, Mazda lost me as a customer. I canceled my purchase of a new 2018 CX-5 GT AWD when I learned Mazda featured the CD for 2018 CX-5 without any prior advertisements and announcements.

Like the big mistake by Mazda North American Operations trying to have 2.2L diesel in the US market, this’s another big mistake which would cost Mazda millions of dollars and lost of many customers. Someone higher up in Mazda Corporate should be responsible for both of these.

And I got feeling the third big mistake by Mazda is coming, the SkyActiv-X ⋯
 
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