How does DFCO work in your car? - Page 3 - Fuel Economy, Hypermiling, EcoModding News and Forum

p38fln · 08-12-2011, 05:37 PM

My F-150 appears to enter it any time the gas pedal is released and it's above something like 10 MPH - I have no scan tools that can show this, but the deceleration is very noticeable.

It's a GTDI engine so should have very precise control over when it fuels or doesn't fuel

CigaR007 · 08-12-2011, 06:10 PM

I noticed that DFCO does not engage itself during engine warm-up, up until 137F.

p38fln · 08-12-2011, 08:50 PM

Here's a question - I just got the TORQUE app on my Droid, and I was watching the fuel rail pressure. Coasting down a hill, it steadily built up to 700 PSI when I had to use the brakes to slow down. It continued rising until I got down to about 45 MPH, then it dropped to about 25 PSI. Was the the DFCO turning off and supplying fuel to the injectors again?

tjts1 · 08-13-2011, 06:01 AM

Quote:

Originally Posted by CigaR007

I noticed that DFCO does not engage itself during engine warm-up, up until 137F.

This is done to get the catalytic converter heated up and working quickly. A lot of the DFCO strategy is designed around maintaining cat temperature.

Piwoslaw · 09-13-2011, 03:57 PM

Quote:

Originally Posted by Piwoslaw

my Grandma has a Corsa C with the 1l, 3-cyl petrol which I get to drive every few months. I'll try to remember to take my SGII with me next time and check DFCO. I have noticed that engine braking is totally different in that car - tiny engine with smaller compression ratio...

I checked today and it appears that fuel consumption is 0 LPH while engine braking all the way down to 1000rpm. I'm not sure when exactly fuel starts to flow again (my SGII seems to refresh slower than in Svietlana), but at 1500, or even 1200, rpm it's still 0 LPH.

Arragonis · 09-13-2011, 04:28 PM

I had 0 GPH at anything over idle in my TDI when coasting. I didn't monitor idle much except when prompted to by someone questioning my habit of lights on all the time where I noticed a change between off and on - can't recall the figures though.

George only engages fuel off at engine speeds over 1400-1600 rpm - the rev counter is not fast enough or precise enough to work out exact speeds.

FastPlastic · 09-14-2011, 04:02 AM

I found dropping down to 50MPH on the highway the Jeep started killing the fuel headed down mid-steep hills. Any faster than that and it has to keep the fuel going to push through the air. Probably the main reason why I managed to get 29.5MPG's on my way up to MN and back.