Does DFCO still work when using cruise control?

[rtom]

Seems like it would be stupid NOT to have DFCO work when using cruise control, but just thought I would ask whether anybody knows for sure. If nobody knows for sure, maybe some careful person with CC can test whether fuel efficiency drops when using CC.

I've been thinking about adding the cheap DIY CC, but there's no way I would do it if DFCO doesn't work when using CC.

[deerebilt]

i know on my 08 sedan s 5 sp w/factory cruise DFCO does work

[rtom]

But are you sure DFCO is working WHEN the CC is on?

Again, seems like it should, but I thought I would like to be sure before deciding on the DIY CC.

[Yaris Hilton]

Works on my 2009 with AT & factory CC.

[127.0.0.1]

ya it will if you are on a sufficient downslope

[TwoBearWisconsin]

Works on my 2009 with AT & factory CC.

Maybe a dumb question, but how can you tell?

[advocate]

Maybe a dumb question, but how can you tell?

An MPG reading device will display 9999 MPG during DFCO. That's the easiest way to tell if it's working or not.

[deerebilt]

you can also feel and hear when dfco shuts fuel off and turns back on.. and yes does workd with cc engage.. scangauge also reads 9999 mpg when fuel shuts off like posted above.

[Yaris Hilton]

Like the man said, you can feel the fuel cut off.

[Reddog99]

If you go down a steep enough hill, the CC will let off the gas all the way in an attempt to not go over your set speed. This is when DFCO will occur.

[Yaris Hilton]

It cuts off the fuel way before that, like 500-700 milliseconds after you release the throttle pedal. (Figure from the manual.) The ECU downshifts the transmission when you're picking up speed downhill and touch the brake, which is the big increase in drag you feel.

Some of you are making way too much of this DFCO. It's a piddly thing, found on most cars nowadays. Just another emissions reduction device.