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'18 Fiesta Gets Cylinder De-Activation


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Im with atomcat here, I think theres confusion between engine deactivation and stop start...whats the 3 cylinder going to run on? 1 cylinder...I doubt that.....sure would sound interesting...

I saw this over a year ago when it was first published.

 

http://www.greencarreports.com/news/1098962_ford-applies-cylinder-deactivation-even-to-3-cylinder-engines-for-fuel-efficiency

 

Cliff notes: it's a rolling system so the engine stays harmonically balanced.

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How does a three cylinder engine produce so much power that it needs to deactivate one or two? Why not deactivate all with a start/ stop feature when stopped at a traffic light? I would think there is a better chance to save fuel there.

The current Fiesta already has stop/start, this cylinder deactivation has to do with reducing on the run engine capacity

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The current Fiesta already has stop/start, this cylinder deactivation has to do with reducing on the run engine capacity

 

I didn't know that Fiesta already had stop /start.

 

I did know what cylinder deactivation is. I just thought it was pointless on a 3 cylinder car. It is seldom used on my brother's Tahoe and that is a truck which it is logical to use it. You'd have to be using cruise control on a level surface for a long time for it to work and then with the slightest touch of the throttle or hill, it stops using the deactivation.

 

A three cylinder car would not have the gobs of reserve power of a huge Chevy V8 and it would seem like a lucky chance it would ever get to use it, so in my opinion it would be useless. Obviously engineers would know more than I do, but then again they also made the choice to use the DCT.

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The cylinder deactivation that Ford uses on the I-3 is different to that used on the Tahoe.

 

The main difference being that the baby Ford simply cuts fuel to the injector in what ever

cylinders it chooses at varying times,so it's not a hard cylinder cut like the GM system.

 

For example, the system may cut fuel on every fourth or fifth injection or whatever timing the ECU determines,

 

The key was in the statement that the engine maintains harmonic balance - that can't be done with the same dead cylinder

on every rotation. The trick is to randomly reduce the amount of firings over several rotations to even out the loss of power

Edited by jpd80
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If you already have a small efficient engine, it's easier to do this type of rolling cylinder deactivation

and still maintain enough active engine capacity in a small vehicle to enjoy improved fuel economy.

 

The GM system of cylinder deactivation relies on re-configuring the whole engine to go from 8 or 6 cylinders to 4

but with a 1.0 liter I-3, the engine is already paired back to the minimum so selective fuel cuts to cylinders means

the engine can be made to have even less actual capacity (90 or 80%?) and get even better economy.

 

I wonder if could Ford apply a similar strategy to its larger capacity DOHC I-4s, V6s and V8,,,,,

Edited by jpd80
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This feature may seem pointless to us, but remember that the Fiesta is most popular in countries where a gallon of gasoline can cost $7-8. In those places, every little bit helps.

It's a workaround for those slack Euro fuel economy test cycles that seem to favor really small engines..

some of the fuel economy figures for sub 1.5 vehicles are near on impossible to repeat in real world driving

I know, I'm trying to with a 1.5 Turbo diesel and failing by about 15%.

Edited by jpd80
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