COD Motorway speeds

[Jimbo10]

Hello again Chaps

Searching the various threads and couldn't find an abundance of answers to this.
Anyone that has the COD engine, at what speeds does it stop running on two cylinders (whilst cruising of course)?

For example, keeping a steady pace of 80mph with a light foot. Would the engine still be running two cylinders, or does it default back to four at a certain speed regardless of the fact that you are cruising at a constant speed?

 

[Neil C]

Don't know about the cylinders, but at a "steady pace of 80 mph" Her Majesty's Constabulary would soon be relieving you of some cash, and gifting you some licence points.

 

[maninthestreet]

So you want someone to break the speed limit to find out for you ??

 

[leosayer1]

There isn't a speed limit per se, the limits are based on torque and revs.

If revs are above 4000rpm or you are using more than 55lb/ft of torque then you are running on 4 cylinders. I doubt it would be possible to cruise at above 80mph while using less than 55lb/ft, but you could use COD on a trailing throttle.

 

[Jimbo10]

In my defence guy's I did say "for example".

For the record, I do not condone the practice of speeding set forth by powers that be. It was purely a hypothetical question...I wouldn't dare break the speeding limits and I know everyone on this forum doesn't either

 

[Jimbo10]

There isn't a speed limit per se, the limits are based on torque and revs.

If revs are above 4000rpm or you are using more than 55lb/ft of torque then you are running on 4 cylinders. I doubt it would be possible to cruise at above 80mph while using less than 55lb/ft, but you could use COD on a trailing throttle.

That Sir, is a gem of a response! Thank you for that info.

 

[RichardT]

I wouldn t get hung up about the COD behaviour.
You can't tell when it cuts in and out (except by looking at the DIS)
And I don't believe it has any detectable effect on fuel.

As the previous poster says, it depends on speed and throttle. It is pretty unlikely that you would see 2 cylinders at 80mph, unless going down hill.
Along the flat at 65-70 you could see it cutting in and out.

To be honest, you don't see 2 cylinders much unless you are driving very carefully.

 

[Wibbly]

I wouldn t get hung up about the COD behaviour.
You can't tell when it cuts in and out (except by looking at the DIS)
And I don't believe it has any detectable effect on fuel.

As the previous poster says, it depends on speed and throttle. It is pretty unlikely that you would see 2 cylinders at 80mph, unless going down hill.
Along the flat at 65-70 you could see it cutting in and out.

To be honest, you don't see 2 cylinders much unless you are driving very carefully.

As they say, YMMV, but in my experience
- I can often tell when it cuts in and out, especially before in cuts out if you;re hovering around the cut-out torque. Engine suddenly gets smoother
- Difficult to tell how if affects fuel consumption as you can't switch it off when it wants to engage. I suspect it does have positive effects otherwise why go to the bother of developing it?
- I can certainly get it to engage on a light throttle on level ground at 70mph
- I see it being activated very frequently in general driving. I guess I have a light foot ;-)

 

[maninthestreet]

I've upgraded from an A1 1.4 (non-COD) to an A3 1.4 with COD.
The best fuel consumption I managed to achieve on a long motorway run in the A1 was 63.5mpg (by driving carefully)
I've only had the A3 for about 10 days, but went on a long motorway run the day after I took delivery and drove it carefully - it was in 2 cylinder mode for at least 75% of the journey, and the average mpg shown in the DIS when I reached my destination was.....63.5mpg. Maybe this will improve once the car has been run-in.

 

[SuperKid]

I've upgraded from an A1 1.4 (non-COD) to an A3 1.4 with COD.
The best fuel consumption I managed to achieve on a long motorway run in the A1 was 63.5mpg (by driving carefully)
I've only had the A3 for about 10 days, but went on a long motorway run the day after I took delivery and drove it carefully - it was in 2 cylinder mode for at least 75% of the journey, and the average mpg shown in the DIS when I reached my destination was.....63.5mpg. Maybe this will improve once the car has been run-in.

My A3 1.4 COD average mpg is 30mpg. I haven't been on the motorway with it yet and I have been accelerating hard here and there. I also drive with comfort mode. I am also new to driving and haven't driven 4 months previously until recently. Any tips to increase mpg??

 

[Wibbly]

Any tips to increase mpg??

Yes. Don't accelerate aggressively. Look at the instrument panel and use it in a mode where it suggests the right gear to be in (as a guide). Also drive as if you thought your brakes had failed or cost lots and lots of money to replace when they wear out - that will encourage a behaviour where you'll be looking ahead all the time anticipating the hazards ahead and driving more smoothly

Lot's of stuff if you search...
https://www.rac.co.uk/drive/advice/driving-advice/fuel-saving-tips/

 

[maninthestreet]

I'm driving exclusively in Efficiency mode at the moment. Avoid hard acceleration and breaking.

 

[RichardT]

I think there was a thread on here ages ago that said efficiency mode made almost no difference!
I really don't like the coasting in efficiency mode.

The only way to decrease fuel consumption is to be VERY easy on the throttle and brake. Boring

 

[SuperKid]

I think there was a thread on here ages ago that said efficiency mode made almost no difference!
I really don't like the coasting in efficiency mode.

The only way to decrease fuel consumption is to be VERY easy on the throttle and brake. Boring

I guess the coasting is part of s tronic when efficiency mode is selected? (think I read somewhere)

 

[cuke2u]

I just drove mine in auto mode, averaged 40mpg how I drove it, mostly urban. On a longer run between 55-65mpg...

 

[traindweller]

In my 150 1.4 I find that the 2 cylinder cuts in and out at all speeds but is regular when at 7o using cruise control, obviously dips out as the hills appear. I never feel it cutting in or out and if not for the DIS would not know it had worked. Perhaps it 's just an illusion Lol

 

[pastey]

My FL 1.4 COD kicks in to 2 cylinder mode all the time at all speeds - the speed doesn't really impact its use it's the throttle. I.e. Mine works in the 2 cylinder mode at the hyperthetical speed mentioned above when on a flat or decline. Any noticeable incline clicks it back to 4 cylinder - tested on private property obviously ... I definitely see the increase in efficiency when it's working in 2 cylinder. 1900 miles in and my average is just over 40mpg with a mixture of roads and a fair bit of over eager acceleration...


Sent from my iPhone using Tapatalk

 

[RichardT]

My FL 1.4 COD kicks in to 2 cylinder mode all the time at all speeds - the speed doesn't really impact its use it's the throttle. I.e. Mine works in the 2 cylinder mode at the hyperthetical speed mentioned above when on a flat or decline. Any noticeable incline clicks it back to 4 cylinder - tested on private property obviously ... I definitely see the increase in efficiency when it's working in 2 cylinder. 1900 miles in and my average is just over 40mpg with a mixture of roads and a fair bit of over eager acceleration...


Sent from my iPhone using Tapatalk

How did you measure the 2-cylinder fuel consumption?

 

[Pintman]

For me, speed is not the factor that determine when 2 cylinder mode cuts in, its down to the revs. Anywhere around 1500-1800 mark, it'll kick in. Lower than that, it won't. I can be driving at 30mph in 4th and it's on the borderline and I can feel it transferring between both modes. Have to say that this is one thing to dislike about the car. Even went back to the dealer with it, but was told that this is the characteristics of this engine.

 

[cuke2u]

In my 150 1.4 I find that the 2 cylinder cuts in and out at all speeds but is regular when at 7o using cruise control, obviously dips out as the hills appear. I never feel it cutting in or out and if not for the DIS would not know it had worked.

Exactly that, never once noticed the change to 2 cylinders and back, I am also very sensitive to any noises and vibrations and this engine is a peach.

 

[Wibbly]

Exactly that, never once noticed the change to 2 cylinders and back, I am also very sensitive to any noises and vibrations and this engine is a peach.

I notice it get a bit lumpy on 2 cylinders at, say, 30mph as I go up a hill before I have to add a little more throttle. Then is changes to 4 cyl and the lumpiness/vibration goes away. If nobody else sees this, maybe a dealer visit is required for me...

 

[RichardT]

I can honestly say that I have never felt that. And based on discussions on here over the past couple of years I have tried to feel it.

 

[Wibbly]

I can honestly say that I have never felt that. And based on discussions on here over the past couple of years I have tried to feel it.

Do you have the display set so it shows when it's running in 2-cyl mode or not? That's a good cue to recognise what you're 'feeling' for...

 

[cuke2u]

Or the display telling you something is happening so you 'think' there is...

 

[Wibbly]

Or the display telling you something is happening so you 'think' there is...

Indeed. But sometimes it's quite obvious to me (as above). Other times it's undetectable to me.

 

[TYb]

You really shouldn't be playing Call of Duty on the motorway, that's nothing short of idiotic

 

[RichardT]

Do you have the display set so it shows when it's running in 2-cyl mode or not? That's a good cue to recognise what you're 'feeling' for...

Exactly. I can see it change but absolutely never feel it.

 

[mr gee]

Read this on a Q2 road test. COD deactivates 2 cylinders at loads of up to 73.8 ft/lbs on a constant throttle between 2000 and 3200 rpm.

 

[AndrewB]

Our 1.4ACT (COD) will run on 2 cylinders right down to about 1500RPM.

I always speculated this is perhaps uncoincidentally around twice the idle RPM, as if to maintain running the engine within the design parameters of it's minimum speed... Maybe the designed minimum "ignitions per period of time" is maintained given half the number of cylinders... Is @GSB anywhere nearby with his fiendishly complicated/expensive engineering books?

As regards maximum road speed, from experience it'll definitely run continuously on 2 cylinders at 70mph on the level. https://www.volkswagen.at/tiguan/act suggests up to 80mph.

As others have said though, within those bounds of ~1500RPM and 70+mph, it's purely down to torque requirements, so a slight incline or a slight throttle movement are enough to switch back to 4. It's a very gentle transition though. (much less pronounced than transitioning the dead spot around 2400RPM in a cold-started VR6...)

 

[GSB]

Our 1.4ACT (COD) will run on 2 cylinders right down to about 1500RPM.

I always speculated this is perhaps uncoincidentally around twice the idle RPM, as if to maintain running the engine within the design parameters of it's minimum speed... Maybe the designed minimum "ignitions per period of time" is maintained given half the number of cylinders... Is @GSB anywhere nearby with his fiendishly complicated/expensive engineering books?

I'd suggest that there's an element of overcoming the inertia of those two "dead" pistons at idle speed without excessive fuel use and with a turbo that's almost asleep, but mainly, I think it's a question of what the average buyer finds acceptable in terms of Noise, Vibration & Harshness.

When running on two cylinders the engine is not optimal it terms of its balance and vibration. At 1500 rpm in four cylinder mode, you're getting 12.5 crankshaft revs per second, and 50 combustions per second. When you switch to COD, the number of combustions halves to 25 per second. Drop to idle speed of 750 rpm in this mode and you'll have 12.5 combustions per second.

Whilst the engine will undoubtedly run at this speed and frequency, it won't sound or feel very nice, and customers don't want an engine that sounds or feels like a cement mixer. So this switch back to four cylinders from 1500 rom to idle ensures the engine still feels smooth and free revving to the customer.