Originally Posted by wwest

First, the US regulations on advertised HP require that the statement only be true within +/- 10%. So my 300HP 2001 C4 may only have 270HP. I hope not, maybe on the 330HP "side".

The best we can do is go off the manufacturer's numbers and assume they would put forth their technology in the best light while doing there best to avoid a public backlash when they don't meet the numbers.

You seem to believe that SKYACTIV is a more efficient and powerful technology. I pointed out HARD numbers on production vehicles from both manufacturers that don't support your belief. It would be nice if you had hard numbers to support your case instead of a theoretical +/- 10% and some non-related Corvette reference.

With the advent of GDI/DFI capability Ford initially went, remains predominantly, in the direction of using that additional compression capability to provide BOOST "space", of use maybe 1% of the time. Probably only as high as 1% if the driver happens to be of the "boy-racer" mentality/persuasion.

EcoBoost/TwinForce increases the "effective" compression ratio to 12-14:1 using turbo BOOST, wasting the DFI/GDI capability the clear majority of driving time.

Whereas SkyActiv, increasing the base/native CR to 12-14:1, increases FE >98% of the time.

Then why don't we see SKYACTIV being more efficient in the 2.0L Mazda3/Focus example I gave? We can also wait and see how the 2013 CX-5 compares to the 2013 Escape, since both will be sporting SKYACTIV/EcoBoost. Early indications are that the 1.6L Ecoboost option will have the more power output to the 2.0L SKYACTIV (173HP/155HP) (170/150ft.lbs).


$5.00 gas?
Sure. $6, $7, $8, $9, $10 or more, eventually. But let's make a point here.

Ford is using their technology to meet customer/market demands and offer class leading FE in MANY categories (please, see all my previous links for examples/info). Until we see SKYACTIV beating, notably exceeding, Ford's FE and power, I don't see how you can say Ford's Engineers should be embarrassed!

Originally Posted by wwest

You would BOTH be wrong. Think about it, firing up the ~100HP ICE only to power the 5-7HP A/C represents a horrible waste. Compare that to the ICE being able to more efficiently, and with a much shorter period, to fully RECHARGE the HV battery.

In the initial case the ICE must run for the entirety of the compressor cycle(s). In charging the HV battery the ICE can be run at the most optimal overall level, high percentage of that ~100HP capability going directly into the battery.

Using the HV battery to run the A/C might therefore result in a RADICALLY lower ICE duty cycle and higher FE vs running the A/C directly..

Originally Posted by MyPart

I never said you had to waste the rest of the power from the idling ICE.
If you would read my full response you would see that I addressed that in the very next line, "...there is an ICE load/efficiency point that can be used where excess charge is captured for future propulsion. Since the ICE is already running, you might as well target a efficiency point of the engine and store that excess when possible."

I can tell you that the 2008 FEH does charge the battery while being forced to idle due to cooling request. The problem comes when the SOC is maxed out. Obviously, a larger capacity battery would help in this case (and many others).

With the current battery capacity, it seems that the best of both worlds would have been a hybrid compressor that can be belt or electric driven. That way, you can leverage the battery when ICE-OFF and the ICE when ICE-ON. But then you introduce more complexity and cost and some people would complain about that.

Originally Posted by wwest

EcoBoost/TwinForce futures:

Ford engineers should be mightily embarrassed (quite possibly ARE) that almost any mechanic, a shade-tree mechanic even, could take an gas-guzzling (relatively) EcoBoost/TwinForce engine and quickly convert it to the SkyActiv design and thereby end up with substantially improved FE.

Originally Posted by GaryG

Ford eliminated the HV battery Aux. A/C in the 2010 and newer FEH. I think that was a mistake because the ideal (efficiency) battery temperature is 78F degrees. Ford also went to an electric A/C compressor that year which eats up what little SoC range in that HV Battery. This leaves very little battery SoC for EV use in city driving. It has been my opinion that an electric compressor should only be used in a plug-in Lithium battery where charging does not come from the engine.

The '09 and older FEH did not have HV battery cabin venting, so there was less fan noise. In other words, on the newer FEH if it's hot out, you need to run the cabin A/C cold to keep the battery near 78F. This was one reason I did not purchase a FFH or newer FEH.

This maybe one reason why Ford is discontinuing the FEH after 2012. Ford can now go to a cheaper gas version and get as good if not better MPG than a FEH. In 2013, the Escape will be a lighter design with an available 2.0L EcoBoost engine, which should have more power and better MPG than an FEH.

The 2013 FFH will be available with a lithium battery and later in the year be available with a plug-in lithium battery. I wouldn't waste my time and money on a non plug-in FFH and a plug-in FFH I expect will cost well over $40K before tax incentives.

I got lucky and purchased new the most efficient FEH which was the '09 model with the aux HV battery A/C and belt driven A/C compressor. I don't have to run the cabin A/C to keep the battery near 78F and can drive EV to the max of 40mph in the city. This allows my '09 FEH a lifetime MPG to be at 53.9mpg for 30,000 miles.

It is important that you locate your '12 FEH HV battery vents and never block them!

GaryG