2004 to 2020 Mazda 3 Forum and Mazdaspeed 3 Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
20 Posts
Discussion Starter #1
2021 3 Hatchback, still does not have 600 miles on it yet.
Curious how you can tell when it goes from 4 to 2 cylinders. I have not noticed any difference in ride or vibration levels.

It does seem that on a straight, level highway at 75mph, the "current" MPG readout on the dash will jump from 32 to 40 for no other apparent reason than CD must be coming on.
Am I correct in that assumption?
 

·
Registered
Joined
·
100 Posts
2021 3 Hatchback, still does not have 600 miles on it yet.
Curious how you can tell when it goes from 4 to 2 cylinders. I have not noticed any difference in ride or vibration levels.

It does seem that on a straight, level highway at 75mph, the "current" MPG readout on the dash will jump from 32 to 40 for no other apparent reason than CD must be coming on.
Am I correct in that assumption?
I am pretty sure your Hatchback doesn't have cylinder deactivation according to Mazda usa.

280781

280782
 

·
Super Moderator
Joined
·
5,947 Posts
Check the display. Home screen -> information -> fuel efficiency monitor. See if your car has the power flow display that shows when the CD is activated. However, the 2021 Mazda 3 no longer has this as a feature other than on the Select trim sedan.....
 

·
Registered
Joined
·
100 Posts
Check the display. Home screen -> information -> fuel efficiency monitor. See if your car has the power flow display that shows when the CD is activated. However, the 2021 Mazda 3 no longer has this as a feature other than on the Select trim sedan.....
The AWD sedans still have them as well..,sigh.
 

·
Super Moderator
Joined
·
715 Posts
It's frustrating that salesmen don't learn their cars well enough to inform their buyers. Is it that hard to do a bit of homework?
 
  • Like
Reactions: hoodlum

·
Registered
Joined
·
407 Posts
It's frustrating that salesmen don't learn their cars well enough to inform their buyers. Is it that hard to do a bit of homework?
It's not hard. Sadly many are just not interested. Rarely if ever have I gone car shopping and learned anything new from a salesman beyond infotainment features. Lots of times they have given me misinformation about their cars or the competition's.
 

·
Registered
Joined
·
1,555 Posts
It's not hard. Sadly many are just not interested. Rarely if ever have I gone car shopping and learned anything new from a salesman beyond infotainment features. Lots of times they have given me misinformation about their cars or the competition's.
It's very true. All they care about is making money any way they can - who cares if they have to lie to do that?

When I was car shopping 5 years ago (and eventually bought my 3) I decided to give ford a look. Not a big fan of ford, but they had a focus hatchback I could get in manual. I ended up walking out because the salesman couldn't even tell me what motor it had let alone what options I had. It was pathetic. I told him I'd be going somewhere where the staff can handle doing their job. Mazda dealer was practically across the street :)
 

·
Registered
Joined
·
100 Posts
I'm holding out hope the sedan in AWD form gets rid of it completely for 2022. Its the one thing keeping me from leasing once. Tried contacting Mazdausa and they fed me some bs excuse. I said why does the Mazda 3 Hatch and CX-30 no longer have it. No response.
 

·
Registered
Joined
·
135 Posts
i wouldn't mind cylinder deactivation, as long as it only kicked on while cruising on the highway, and only if there's a way to enable/disable it. perhaps they can add an "eco" mode to the sport mode switch
 

·
Registered
Joined
·
20 Posts
Discussion Starter #11
Thanks all, you are right, it does not have it. And for a gain of only 1mpg, I'm glad it doesn't. Too many complications for a minute gain in gas savings.
 

·
Registered
Joined
·
39 Posts
I never noticed the cylinder deactivation but after getting the latest software update it’s very annoying and obvious now at 35-45 mph cruising as it rumbles when switching over and almost feels like the engine is stumbling or misfiring for a second or two but it coincides exactly with the monitor indicating 2 cylinder to 4 cyclinder switchover. Sometimes I get low 20’s mpg for short trips but I usually get 28-30 mpg in the city and mid to high 30’s on the hwy.
 

·
Registered
Joined
·
100 Posts
I never noticed the cylinder deactivation but after getting the latest software update it’s very annoying and obvious now at 35-45 mph cruising as it rumbles when switching over and almost feels like the engine is stumbling or misfiring for a second or two but it coincides exactly with the monitor indicating 2 cylinder to 4 cyclinder switchover. Sometimes I get low 20’s mpg for short trips but I usually get 28-30 mpg in the city and mid to high 30’s on the hwy.
See that worries me long term, more wear and tear on the engine mounts from switching to 2 to 4 cylinders. Plus other unknown issues down the road. Honda's V6 engines had a lot of issues and got sued because of it.
 

·
Registered
Joined
·
366 Posts
I never noticed the cylinder deactivation but after getting the latest software update it’s very annoying and obvious now at 35-45 mph cruising as it rumbles when switching over and almost feels like the engine is stumbling or misfiring for a second or two but it coincides exactly with the monitor indicating 2 cylinder to 4 cyclinder switchover. Sometimes I get low 20’s mpg for short trips but I usually get 28-30 mpg in the city and mid to high 30’s on the hwy.
Yup mine started after software update as well. Never gone away really(think improved a bit with their TSB)

When I first bought my car and for about 6000 km it was absolutely flawless, so smooth and quiet I had to go looking for the CD screen. Took it in for software update and the same thing happend, it became very noticeable and at the speeds you mention I notice every single time it switches, particularly on long flat roads.

Do you know what software update you got?
 

·
Registered
Joined
·
366 Posts
I don't know which update I had sometime last year in Sept/Oct maybe. Do you know the TSB for this issue?
I think I found it: TSB # 01-009/20
MC-10177841-0001.pdf (nhtsa.gov)
Yes that's it

Been warned though, some have said they think it got worse after it. For me though it did help quite a bit for speeds outside of the 80-90 kmh speed range. Before I had it done it would rumble and make noise above100 kmh but now it's silent.

Didn't make mine worse that's for sure
 
1 - 17 of 17 Posts
Top