Cylinder Deactivation vs Turbocharger

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In order to meet CAFE gas mileage standards manufacturers are experimenting with new technologies such as cylinder deactivation and turbocharging. In addition both are getting direct injection.

It’s interesting that cylinder deactivation and turbcharging are almost opposite. In one, you take a powerful engine and deactivate some cylinders to make it a weaker but more fuel efficient engine, and in the other you take a fuel efficient but weak engine and make it powerful. The Ford F-150 with the 3.5 twin turbo is one example and the GM 6.2 liter with the AFM system is another.

What is your opinion on the technology and which system would you rather own.
 
Turbo over cylinder deactivation any day.

Edit: Tossing CAFE into the bin of failed schemes would be the ideal answer.
 
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I suppose I'm in the camp of neither. If I had to choose a fuel economy engine it'd be a pre emissions diesel. If I was forced to choose a turbocharged gas engine or an engine that shut off cylinders I don't know which one honestly. A port fuel injection turbocharged engine isn't so bad, but I'd rather not have a DI only turbo. Perhaps the EB gen 2 with direct and port injection wouldn't be bad. The GM LS engine with AFM is all around much simpler and easier to work on than the EB Ford. If I had to pick between the EB Ford and a LS Chevrolet it'd be the LS all day.

Meanwhile I'll just keep driving things I can actually work on that are devoid of excessive complex cylinder management devices, direct injection and forced induction.
 
Not sure your question can be answered. Turbocharging now uses small engines to bring them up to competitive power with non turbo engines, In past turbo engines the basic engine had more cubic inches and the turbo was added for increased HP. Today's turbos are for daily drivers and not necessarily for high performance. I am still undecided on cylinder deactivation because of past history and very little history for today's engines. A toss up in my opinion until we get more statistics. Ed
 
Turbo with EFI, they can keep cylinder deactivation and DI.
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In my thinking, there is another reason for CAFE. Electric cars are coming. If there is no CAFE, short sighted governments will legislate ICE ( internal combustion cars) out of existence.
 
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How about, small displacement 1.5L 4 cylinder w/direct injection & turbocharger as well as engine shut off at complete stops? 2018 Equinox!
 
Originally Posted By: Char Baby
How about, small displacement 1.5L 4 cylinder w/direct injection & turbocharger as well as engine shut off at complete stops? 2018 Equinox!


Now you're talking, with stop/start and no way to disable it.
 
How about a 7L+ V12 with 2 (or more) turbos, cylinder deactivation and start/stop? Throw in direct AND port injection, maybe give it two plugs per cylinder for good measure.
 
Originally Posted By: demarpaint
Originally Posted By: Char Baby
How about, small displacement 1.5L 4 cylinder w/direct injection & turbocharger as well as engine shut off at complete stops? 2018 Equinox!


Now you're talking, with stop/start and no way to disable it.


I know, right?
I'd like to have the option of disabling it.
 
Turbo over variable displacement, hands down. If my info is correct VD usually only gains 1-2 MPG where, say, a car offered with a 1.4T and 1.8-2.4L NA engine can be 4-5 MPG different between the engines. Not to mention it seems a lot of the engines with VD have oil consumption/sludging issues that in some cases literally can't be prevented without substantial over-maintenance, where today's turbos just need regular (but not super short) OC's with quality synthetic to last a very long time.
 
Originally Posted By: rooflessVW
How about a 7L+ V12 with 2 (or more) turbos, cylinder deactivation and start/stop? Throw in direct AND port injection, maybe give it two plugs per cylinder for good measure.


And DOHC with VVT.
 
You only need cylinder deactivation or turbos if you want power AND mileage. If you just want mileage, an NA of the right size with some good gearing does pretty well with much less complexity.
The 2.5 subaru's with the CVT don't give up mileage to the turbo CUV's at all, just some torque and hp.
 
Originally Posted By: Snagglefoot
Originally Posted By: rooflessVW
How about a 7L+ V12 with 2 (or more) turbos, cylinder deactivation and start/stop? Throw in direct AND port injection, maybe give it two plugs per cylinder for good measure.

And DOHC with VVT.

Of course! 5 valves per cylinder.
 
Originally Posted By: Snagglefoot
In order to meet CAFE gas mileage standards manufacturers are experimenting with new technologies such as cylinder deactivation and turbocharging. In addition both are getting direct injection.

It’s interesting that cylinder deactivation and turbcharging are almost opposite. In one, you take a powerful engine and deactivate some cylinders to make it a weaker but more fuel efficient engine, and in the other you take a fuel efficient but weak engine and make it powerful. The Ford F-150 with the 3.5 twin turbo is one example and the GM 6.2 liter with the AFM system is another.

What is your opinion on the technology and which system would you rather own.



Neither. I prefer a big engine WITH a turbo, hence why I bought the 1er.

Can't stand VCM. So many issues with vibrations. Just an easy way to get better FE without designing an actually good engine. My 3.0L I6 135i gets better FE than my Civic when highway cruising at 120 km/hr (my normal speed).
 
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Tricky one. i have no experiernce of either, and would probably prefer to keep it that way, but I understand that the common implementations of variable displacement have (aftermarket?) control and deactivation options, giving you a choice.

In contrast, I'd think it'd probably be difficult to run most turbo cars satisfactorily with the turbo deactivated even if that was possible.

Even though turbo technology is longer established, the turbo still seems an inherently highly stressed device, perhaps giving more potential for fragility.

So the above would suggest a vague preference for variable displacement.

In practice the choice probably depends on the vehicle. I know Ford have a 3 to 2 engine, but in general I think VD is cfurrently for V8's and up. Since its not very likely I'll have a V8, and fairly likely I'll have another small-engined car, I'm probabkly more likely to have a turbo.
 
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I would not prefer one over the other. Personally, I feel that using a system such as VVT-iW which allows for Atkinson's cycle as needed is a better design. It does not allow certain cylinders or the cats to cool down too much, and does not have the issues with vibration like VCM and the like do. Turbos are nice for a flat torque curve and highway mileage, but they really suffer in city mileage and maintenance costs. At this point in time, I personally would like to see more research going into producing lighter vehicles. The new full size trucks are doing exactly what they should be doing. The Ford Fusion with the EcoBoost engines would get significantly better mileage if the vehicle was not as heavy as it is.
 
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