EOC coasting in gear

[HydroJim]

I'm wondering if i installed an injector cut-off switch and left the engine in gear for coasting, I could then simply turn the injectors back on and the engine would start? Assuming there was still spark being delivered?

I would still EOC in neutral sometimes because it's more efficient when I know I can coast for a while , but it may be more convenient to be able to start the car just by flipping a switch instead of bump starting. It would allow for more engine off coasting in town where you still want to have full brake power.

[GRU]

If you do that it's the same as most newer vehicles shutting off the injections on decelaretion in gear. The car will slow down too fast to make a difference in fuel saving. When i had my 5speed civic i only used that (in grear) when i needed to slow down quickly.

[HydroJim]

Now that I think about it, it seems pretty impractical.

[Ryland]

My Civic does that on it's own and I find it to be very useful and that it doesn't seem to slow me down much at all! sure I can down shift and slow my self down when I'm coming to a stop, but most of the time it's just a matter of letting off the gas for a few seconds, if you do install a switch like this hook it up to a vacuum switch on the intake so it cuts fuel under high vacuum.
I'm kind of suprized that your car doesn't do this already on it's own.

[bandit86]

My corolla cuts out if I decelerate in gear and it coasts a long time, not much difference if in gear or not, but coasting in gear the engine is on doing nothing and using fuel. Tough call, 6 of one and half dozen of other

[3-Wheeler]

Originally Posted by GRU

If you do that it's the same as most newer vehicles shutting off the injections on decelaretion in gear. The car will slow down too fast to make a difference in fuel saving. When i had my 5speed civic i only used that (in grear) when i needed to slow down quickly.

It really makes a difference on what type of car you have.

In the Insight, I max out at about 120 mpg in the summer with straight line driving.

But when I start cutting the injectors, I have maxed out the instant mile per gallon indicator at 150 mpg on numerous occasions. So with the right car, you can get way better mileage by coasting.

P&G is exactly the same technique used by Universities to get mileage over 1000 mpg and higher. There's no way they could get even close to that with the engine idling most of the time!

I even coast with the motorcycle engine off and get another 5% in fuel savings. But that's only because the motorcycle breaks so much wind for it's size. With a decent full body fairing, that number would go way up.

Jim.

[GRU]

Don't get me wrong, i know it saves a little bit of fuel but i wouldn't use it unless you want to slow down at the pace you would leaving it in gear (example: needing to stop because the light just turned red). If he's driving down the road and doesn't need to slow down he's better off to pulse and glide.

[HydroJim]

I don't believe my Ford Focus does or the effect is very subtle. the ultragauge doesn't display 999 mpg when I let off the gas. My mom's 2008 Jeep Patriot has very distinct DFCO that you can feel, but it is really nice when driving in town because you don't have to use the brakes at all.

[euromodder]

Originally Posted by HydroJim

I'm wondering if i installed an injector cut-off switch and left the engine in gear for coasting

When in gear it's not coasting, it's braking.

Surely a 2000 Focus has DFCO ?

It would allow for more engine off coasting in town where you still want to have full brake power.

Adapt your driving style so you don't need to use engine braking that much.
That will reduce your fuel consumption, as you won't be pumping energy in a car when itdoesn't need power.

[HydroJim]

aside from feeling the drag, how would I check for DFCO? as far as I can tell, it doesn't have it, but I've only logged about 200 miles on my car. I'm a new driver but I injured my back so I haven't driven in about 2 months. If my memory serves me right, my car coasts equally in or out of gear. I could be wrong about this though