Dfco - Fuel Economy, Hypermiling, EcoModding News and Forum

hyperyaris · 06-12-2009, 12:15 AM

Do all modern cars have Deceleration Fuel Cutoff, or just some? Mine does, and I take advantage of it all the time. Instead of coasting, I use engine braking.

Christ · 06-12-2009, 12:36 AM

engine braking is great, if your intention is actually to slow down... the point of coasting is to allow you to use stored energy (momentum) as long as possible... in the most efficient way possible, to get the largest net effect possible. This means "nothing holding you back".

DFCO is a great way to save fuel, if you use it properly. It doesn't compare to P&G or EOC though.

hyperyaris · 06-12-2009, 01:33 AM

Forgive my ignorance, but what is P&G and EOC?

Christ · 06-12-2009, 01:36 AM

Pulse and Glide
Engine Off Coasting (using neutral or clutching w/ the engine off.)

hyperyaris · 06-12-2009, 01:46 AM

Ok thanks. I have actually heard of those. But isn't C&G with the engine off dangerous because of he lost of power steering and steering lock? Or, are there mods to solve that?

Christ · 06-12-2009, 01:48 AM

Lost power steering is only as dangerous as the person operating the vehicle... you get used to it.

Steering lock can be fixed by not turning the key to the lock position. Some cars have odometers that don't record mileage with the key in the "off" position... the fix to this is leaving the key off, and manually switching off the ignition/fuel systems (requires mods).

hyperyaris · 06-12-2009, 01:49 AM

Ooh I am fascinated now. Hmm...I might try tomorrow heh.

Christ · 06-12-2009, 01:56 AM

As long as you have a manual, you're fine rolling around w/ the engine off. Please "test" yourself in an unoccupied area, until you're used to the lack of power steering, such as a parking lot, at low speeds.

Don't get hurt, and there's a link at the top of the page that describes 100+ Hypermiling Tips that you can follow from any page on the site (that I'm aware of.). It has good information that you might want to start with before getting too involved with ideas.

PaleMelanesian · 06-12-2009, 11:39 AM

Steering lock is 2 clicks back. You only need 1 click back to shut down the engine. Then, as soon as it stops, click it back to the ON position. Your electronic systems (you like airbags?) and odometer will start running again.

You will lose power steering, but at anything above parking lot speeds, you don't need it anyway. Brakes are good for 3-4 applications before the vacuum boost runs out. If I use the brakes twice (rare), I like to do a quick bump-start and turn it back off to replenish the boost. That way, if an emergency comes up, i'm ready.

hummingbird · 06-12-2009, 11:58 AM

You Don't necessarily lose power steering - My City's EPS kicks right back in when I turn the wheel beyond a certain angle if the key is turned back to ON position. Only downside is the mild surprise factor when it does kick in, but it is easy to manage because I know it will.