Ford exploring cylinder deactivation for 1.0L EcoBoost; testing shows up to 6% fuel efficiency improvement
12 May 2015
Ford, in collaboration with the Schaeffler Group, is investigating different cylinder deactivation approaches on its award-winning 1.0-liter, three-cylinder EcoBoost engine. On-road tests using a working prototype showed fuel efficiency improvements of up to 6%, according to Dr. Andreas Schamel, director, Ford Global Powertrain, Research & Advanced Engineering in Vienna last week.
For the test, the engineers also developed a new dual mass flywheel. This enabled cylinder deactivation to take place at a wider range of engine loads and speeds, and helped minimize noise, vibration and harshness levels.
For testing, engineers equipped a Ford Focus 1.0-liter EcoBoost with cylinder deactivation hardware that they could monitor deactivation of one cylinder, and also a “rolling” cylinder deactivation to run the engine in half-engine mode.
Rolling cylinder deactivation, as explained by Schaeffler, allows all cylinders to be deactivated after every ignition cycle and reactivated during the next. Cylinder deactivation thus alternates within a single deactivation phase and not each time a new deactivation mode is introduced. The benefit is a more well-balanced temperature level inside the combustion chambers and consistent firing intervals for three-cylinder engines operating in deactivation mode.
|Pattern of alternating cylinder deactivation (the red phase designates the active operating mode). Source: Schaeffler. Click to enlarge.|
They also fitted the prototype with a newly developed system that combined the dual mass flywheel, a pendulum absorber, and a tuned clutch disc; and is particularly effective at low revs. As well as enabling a wider operating range of cylinder deactivation, this system helped counteract any effect that the cylinder deactivation had on levels of noise, vibration and harshness.
Fuel efficiency improvements were recorded in homologated conditions and during test drives of the first prototype vehicle, for a typical commuter distance of 55 km (34 miles) on a combination of motorway, city roads and rural roads, in and around Cologne, Germany.
Schamel said that cylinder deactivation is among a number of fuel efficiency solutions Ford is investigating for the 1.0-liter EcoBoost, at the European Research and Innovation Centre in Aachen, Germany.
Even for an aggressively downsized engine such as the 1.0-liter EcoBoost, a significant improvement in vehicle fuel economy could be found by exploiting cylinder deactivation. The highest priority in the development of new combustion engines for automotive applications is the ongoing reduction of fuel consumption.—Andreas Schamel
Ford’s 1.0-liter EcoBoost engine last year became the first engine to be named International Engine of the Year three times in a row. Downsized EcoBoost engines combine surprising power with excellent fuel efficiency through direct fuel injection, turbocharging, and variable valve timing. EcoBoost-equipped vehicles last year accounted for one in four new Ford vehicles sold in Europe. The 1.0-liter EcoBoost, the most popular, is available with automatic as well as 5-speed, and 6‑speed manual transmissions, and across 10 different models—from Fiesta to the all-new Mondeo.
Ford is working with Schaeffler and other partners in the ACTIVE (Advanced Combustion Turbocharged Inline Variable valvetrain Engine) project in the UK, for which it is receiving about £13 million (US$20 million) from the UK government to accelerate the introduction of advanced low carbon technologies into mainstream vehicle applications targeting very substantial CO2 savings. (Earlier post.)
Cylinder Deactivation (Schaeffler)
Good, I was wondering when a manufacturer would implement a rolling deactivation...
GM needs this badly... Their bank deactivations are horrible for wear and blow-by(hopefully they will have this soon if they don't already, I haven't looked into it recently)... That 'Normal' oil consumption that you read about in the owners manual is a thing, 1 quart per 1000 miles can and does happen often. (every auto maker has that, and usually it is for break in)
My personal vehicle doesn't burns a quart in over 7000 miles(and 180,000 on the odometer). I've worked on cars with 5000-30,000 miles where they were burning 3-5 quarts in 3,000 miles. No, there was not any leaks.
On a side note, I would be happy with a sluggish 1L in a midsized vehicle... as long as it didn't have too small of a turbo. I really think Ecoboost/ any other turbo application would be better if they allowed for "lag" and created better economy at typical cruising RPMs...
My brothers truck can beat the sticker MPG handedly, but highway MPG can suffer greatly as you get into boost, and at certain speeds it is unavoidable due to the load on the engine... if the turbo came in later, it could greatly improve economy. This could be done with a tune, and opening the waste gates, or adjusting VGTs (if available) or otherwise adjusting the geometry.
I believe Roush was working with this engine and an electric turbo fed by supercaps...it basically gave you a boost on takeoff if you wanted it, and stayed out of boost otherwise.(I am probably very mistaken on the details)
Posted by: CheeseEater88 | 12 May 2015 at 10:08 AM
First just a coupla' nit picks. The phasing graph axis should end with 1440 deg not 1400.
And surely the igniter firing order could just as easily be 123..123 etc as be 132..132 ? If you look carefully you can see the sequence 321..321.. which is just a 123 engine being made to run backwards !
Until this article I had never considered the possibility of rolling deactivation before. It seems like a good idea, and before a reader tells me how obvious this is, I might say that pretty much most good ideas are obvious, once someone has taken the time to point them out.
So if you are cruising along with rolling de-activation engaged and suddenly need to accelerate then the firing circuits will return to the normal 3-cylinder sequence. In other words, the 480 deg firings revert back to a normal 240 deg sequence. But what is the main advantage here ? Does it allow the crankshaft to run slower in cruise with just three firings per four rotations thus allowing the cylinder loadings to be raised for max effcy ?
I would like Ford to take this to a parallel twin model with a total cylinder area equal to that of the three cylinder they are now playing with. That would ensure the same power and by using the exact same stroke would subsequently ensure the same torque. Advantages would be that valve train friction losses would drop by 50%. And then there's the cost factor of the engine being proportional to the number of machined parts. I think it is fair to say that component size is not a cost driver as we are talking of parts made from iron and aluminum here.
Posted by: T2 | 12 May 2015 at 02:57 PM
GM either has or will have a more random deactivation scheme that is basically load following. For a V8, it could fire 5 cylinders one revolution, then 4 or maybe even 3 and all cylinders would see an equal loading.
Posted by: sd | 12 May 2015 at 03:57 PM
T2, Fiat already has the TwinAir engine (another one that I really like).
A parallel-twin engine isn't necessarily less expensive nor more efficient than an inline-three, though. The Ford three-cylinder, and a number of others, can get away with not having a balance shaft if the engine mounts are carefully designed, but with a parallel-twin, it's pretty much unavoidable. In motorcycle applications, the NVH can be accepted in some cases, but most people wouldn't tolerate it in a car. The Fiat TwinAir is counterbalanced.
I have my doubts that cylinder de-activation on an engine this small would save much in the real world ... it may just be another thing that increases the discrepancy between the EPA / NEDC tests and the real world. I have a car with a 1.0 3-cylinder, and it doesn't spend a whole lot of time at light engine load and higher revs where cylinder de-activation could help. Real world highway driving, the load on the engine is already pretty high most of the time. Real world city driving, the revs are low and cylinder de-activation would probably give unacceptable vibration. Cylinder de-activation schemes generally don't operate at low engine revs.
Posted by: Brian P | 16 May 2015 at 06:13 PM