My New 2020 Mazda AWD Has Cylinder Deactivation

[Soba1]

I read a while back where someone may have been complaining that they couldn’t get their cylinder deactivation going when they hit 70mph.
Playing around with my 2020 CX-5 I realize that I have it.
I suspect that’s why when I went on my first short road trip which was 70 miles one way. Going from where I live half of the drive or just under half is down hill.
After getting off the fwy. The rest of the drive was back roads with slight inclines ever so often was 55/60mph. That drive going to I was averaging 39mph.
In retrospect my only conclusion was that cylinder deactivation had played a great part in that.
Now to present after discovering I have that feature I keep the cylinder deactivation screen up along with the current mpg.
I know some may not think to ask but yes I have been able to engage CD during city driving. Now when you car doesn’t feel the need
to push CD will activate. Its just a matter of finding that sweet spot on the gas pedal. Also what I notice on the CD monitor screen.
When coming to a red light I take my foot off of the gas a cruise to the light all cylinders shut down. When stopped at the light all four
cylinders are in use.
Short city hops last night I noticed 23mpg yeah I know a RAV4 hybrid will average much better.
With all that being said for for those who truly love Mazda CX-5’s u have to play around with it to
maximize your fuel economy. In hilly areas it can be challenging foot off the gas or light going down hill decreases
consumption dramatically.
Its just a matter of finding that sweet spot on the gas pedal
Jump to the 3:17 min mark of this Vid and watch from there this should help you better understand CD

Mazda CX-5 SkyActiv G Cylinder Deactivation for Better Fuel Economy

in 2018, Mazda added additional technology of cylinder deactivation to its SkyActiv G line of engines. This technology is standard on all Mazda CX-5 vehicle...

youtu.be

 

[181962]

I read a while back where someone may have been complaining that they couldn’t get their cylinder deactivation going when they hit 70mph.
Playing around with my 2020 CX-5 I realize that I have it.
I suspect that’s why when I went on my first short road trip which was 70 miles one way. Going from where I live half of the drive or just under half is down hill.
After getting off the fwy. The rest of the drive was back roads with slight inclines ever so often was 55/60mph. That drive going to I was averaging 39mph.
In retrospect my only conclusion was that cylinder deactivation had played a great part in that.
Now to present after discovering I have that feature I keep the cylinder deactivation screen up along with the current mpg.
I know some may not think to ask but yes I have been able to engage CD during city driving. Now when you car doesn’t feel the need
to push CD will activate. Its just a matter of finding that sweet spot on the gas pedal. Also what I notice on the CD monitor screen.
When coming to a red light I take my foot off of the gas a cruise to the light all cylinders shut down. When stopped at the light all four
cylinders are in use.
Short city hops last night I noticed 23mpg yeah I know a RAV4 hybrid will average much better.
With all that being said for for those who truly love Mazda CX-5’s u have to play around with it to
maximize your fuel economy. In hilly areas it can be challenging foot off the gas or light going down hill decreases
consumption dramatically.
Its just a matter of finding that sweet spot on the gas pedal
Jump to the 3:17 min mark of this Vid and watch from there this should help you better understand CD

Mazda CX-5 SkyActiv G Cylinder Deactivation for Better Fuel Economy

in 2018, Mazda added additional technology of cylinder deactivation to its SkyActiv G line of engines. This technology is standard on all Mazda CX-5 vehicle...

youtu.be

If somebody can't get cylinder deactivation to operate at any speed above 10 mph under just about any conditions, there may be something wrong with the vehicle. Get up to whatever speed, ease off the gas (but not coast), and you should be able to find just the right accelerator pressure that gets you into two cylinder mode however briefly.

The problem is keeping the vehicle in two cylinder mode for any extended period of time without deceleration. This is amply illustrated in the video you posted, whether manually controlling the accelerator or in cruise, where the driver is trying to maintain constant speed. As the commentator mentioned, the weight of the vehicle and rolling resistance will catch up with you. He didn't mention air / wind resistance which is a significant factor. As for all 4 cylinders deactivated when coasting, in prior discussions on this subject several posters stated that any modern engine does this.

Under the right conditions (particularly a downhill drive) and the right speed, while focusing on the real time mpg meter or CD screen display and modulating the gas to maximize 2 cylinder operation, I would not rule out 39 mpg for some period of time but a full tank is highly doubtful. There are not may extended drives down high mountains that don't also involve some steep uphill grades in the process that suck gas not to mention the affect of less oxygen.

Anyway, who wants to live constantly watching gauges and screens to milk every mpg other than in testing mode? That also involves less attention on where it should be--the road ahead.

By the way, when I was in early ownership testing mode I discovered the CD display may not be entirely accurate situationally. At 45 mph, on a flat grade, keeping ever-so-slight pressure on the accelerator, the CD display would flip to no cylinders as when coasting. The vehicle was decelerating at a slower rate than when coasting, suggesting the vehicle was running on two cylinders contrary to the display. Again this is situational, just the right conditions, while watching the CD screen.

 

[Jack Rabbit]

I have a 2018 na and running 17" BBS wheels with nokian snow tires and can consistently get 37 mpg on highway drives @ 55 to 60 mph.
This decreases at 65 mph.

Can't wait til get my Firestone AT tires on which have lower roll resistance than the snow tires.

 

[Soba1]

If somebody can't get cylinder deactivation to operate at any speed above 10 mph under just about any conditions, there may be something wrong with the vehicle. Get up to whatever speed, ease off the gas (but not coast), and you should be able to find just the right accelerator pressure that gets you into two cylinder mode however briefly.

The problem is keeping the vehicle in two cylinder mode for any extended period of time without deceleration. This is amply illustrated in the video you posted, whether manually controlling the accelerator or in cruise, where the driver is trying to maintain constant speed. As the commentator mentioned, the weight of the vehicle and rolling resistance will catch up with you. He didn't mention air / wind resistance which is a significant factor. As for all 4 cylinders deactivated when coasting, in prior discussions on this subject several posters stated that any modern engine does this.

Under the right conditions (particularly a downhill drive) and the right speed, while focusing on the real time mpg meter or CD screen display and modulating the gas to maximize 2 cylinder operation, I would not rule out 39 mpg for some period of time but a full tank is highly doubtful. There are not may extended drives down high mountains that don't also involve some steep uphill grades in the process that suck gas not to mention the affect of less oxygen.

Anyway, who wants to live constantly watching gauges and screens to milk every mpg other than in testing mode? That also involves less attention on where it should be--the road ahead.

By the way, when I was in early ownership testing mode I discovered the CD display may not be entirely accurate situationally. At 45 mph, on a flat grade, keeping ever-so-slight pressure on the accelerator, the CD display would flip to no cylinders as when coasting. The vehicle was decelerating at a slower rate than when coasting, suggesting the vehicle was running on two cylinders contrary to the display. Again this is situational, just the right conditions, while watching the CD screen.

If you are a die hard Mazda enthusiast then definitely something to play with.
I averaged that 39mpg going and I can assure the tank was full because in Ca. traveling long distance your gas price can go from darn to wth in a matter of miles.

 

[181962]

If you are a die hard Mazda enthusiast then definitely something to play with.
I averaged that 39mpg going and I can assure the tank was full because in Ca. traveling long distance your gas price can go from darn to wth in a matter of miles.

So, specifically over how many miles and under what conditions did you record this 39 mpg? That was not clear to me from your posts. And how did you record it? By the dash display or a manual calculation? Anyway, I wouldn't say driving in a manner that milks every drop of gas would typically be thought of as a "Mazda enthusiast" way of doing it.

When Prius came out, less so now, there were enthusiasts who drove to milk every mpg out of the car in a kind of bragging rights contest. This is not that.

 

[181962]

I have a 2018 na and running 17" BBS wheels with nokian snow tires and can consistently get 37 mpg on highway drives @ 55 to 60 mph.

Over what distance? And how did you measure it? In the US anyway, 55-60 mph speed limits are common in and around urban areas but I'm unaware of anyplace where the speed limits don't go up to 65 then 70 and even more by the time you reach the exurbs and beyond.

I'm not aware of anyplace you could drive a tankful at 55-60 on an expressway without driving under the speed limit which is pretty dangerous in most places unless you drive around in circles on an urban/suburban expressway without stopping. It's doable to drive that speed on a tank on backroads but then periodic stop lights and stop signs are unavoidable which makes 37 mpg highly questionable. And all this on snow tires no less.

 

[Jack Rabbit]

Over what distance? And how did you measure it? In the US anyway, 55-60 mph speed limits are common in and around urban areas but I'm unaware of anyplace where the speed limits don't go up to 65 then 70 and even more by the time you reach the exurbs and beyond.

I'm not aware of anyplace you could drive a tankful at 55-60 on an expressway without driving under the speed limit which is pretty dangerous in most places unless you drive around in circles on an urban/suburban expressway without stopping. It's doable to drive that speed on a tank on backroads but then periodic stop lights and stop signs are unavoidable which makes 37 mpg highly questionable. And all this on snow tires no less.

In our state there are highways posted at 55 mph, 65 mph and 70 mph.

Daily 45 mile all highway stretch at 55 mph on nokian snow tires. 37 mpg average showed on Mazda fuel info-meter. A few months ago, to confirm this, one day filled up at the start of drive, drove the 45 mile distance and filled up at end and calculated gallons used to mileage traveled. It was similar, not exact , maybe like 36.83 (or 36.58) or something but pretty damn close.
* Also always fill tank until gas pump stops then pull out and do not put in extra so was standardized test.

Overall my average is 25 to 26 mpg due to the city and country driving.

anticipating your next question, I do alot more country driving than highway as well as leave the car run to defrost windshield in winter, not to mention waiting in drive thru lines, hence this lowers my average drastically.

Also I have been in states where driving less than 70 mph would risk getting rubbed/clipped and at 55 mph would be a death wish, like for instance the Illinois tollway/turnpike and that was almost 30 years ago. Cars whizzing by pulling Dale Earnhardt three wide lane changes. Once in a lifetime was enough for me. Never again.

 

[murky]

I have a 2018. It doesn't directly indicate when CD is active, but I infer it from the instantaneous MPG reading.

My impression is that when I use radar cruise control, it engages more than when I'm controlling the gas with my foot.

 

[Jack Rabbit]

I have a 2018. It doesn't directly indicate when CD is active, but I infer it from the instantaneous MPG reading.

My impression is that when I use radar cruise control, it engages more than when I'm controlling the gas with my foot.

Correct, I use cruise control on the highway hence the 37 mpg.

 

[Soba1]

So, specifically over how many miles and under what conditions did you record this 39 mpg? That was not clear to me from your posts. And how did you record it? By the dash display or a manual calculation? Anyway, I wouldn't say driving in a manner that milks every drop of gas would typically be thought of as a "Mazda enthusiast" way of doing it.

When Prius came out, less so now, there were enthusiasts who drove to milk every mpg out of the car in a kind of bragging rights contest. This is not that.

I came from a hybrid so it’s still a part of me. Conditions were dry I would say 50% Fwy 50% back roads at 55/60mph. I used the dash display.

 

[181962]

I came from a hybrid so it’s still a part of me. Conditions were dry I would say 50% Fwy 50% back roads at 55/60mph. I used the dash display.

I did notice your dash display pics and the mpg shown, in this thread and another.

 

[Soba1]

More on the cylinder deactivation. With a little work I managed to get a 43mph
average. I was on the fwy doing 55/60 in the slow lane of course managing to
activate my CD maybe 60% of the drive I was blown away.
I know crazy but where I live city driving here speeds average say between 45 mph to 60.
I leave the CD monitor up and glance at it in conjunction with the current mpg gauge.
I you live in a city where your average mph is from 35 to 45 with little effort I don’t see
why you couldn’t engage it at least 70% of the time.