Engine braking

[Christ]

Originally Posted by justjohn

I always want more information. :P

I think can guess the basic principals of that though, based on the things already said in this thread and simple logic just applied to fuel conservation.

To some extent, proper planning and proactive driving can lead you, in some cases, to be able to make a complete stop and restart without ever touching the vehicle's service or parking brakes. At times, if I know there is a stop ahead, and nobody is behind me that will be upset by my slow-going, I do exactly this, except I don't let the engine start jerking around on the last few revs anymore, as by this point, the vehicle should coast to a stop naturally, with regard to certain exceptions.

[MarkM66]

Originally Posted by Christ

The engine is still turning while you're engine braking, so even if you turn the key off, you'll still have both brakes and power steering.

And in case you're going to nit pick about the post not specifically referring to engine braking, re read the thread title.

I misunderstood. You're right.

[Christ]

No problem. Y you should set up a garage entry and a intro thread if you haven't already.

[PLTWstudent]

Nothing wears out if you rev match properly, but that kinds ruins the point from an economy standpoint, doesn it? Brakes are easiest to fix

[euromodder]

Originally Posted by PLTWstudent

Nothing wears out if you rev match properly, but that kinds ruins the point from an economy standpoint, doesn it?

You need to give it some gas to rev-match (at higher speeds), but a low rpm and speed, it'll be OK just using the clutch.

Besides, it's only a short dot of gas you need to give it when rev-matching.
After that, you go back to engine braking / DFCO right away, and using no gas.

Brakes are easiest to fix

Brake pads are indeed cheaper than a new clutch
That's why you better let the speed decay first before shifting down.

Looking far ahead on the road, you should be able to anticipate speed changes by lifting your right foot, without requiring shifting down at high speed / rpm.

[slurp812]

Iv always downshifted my cars, when the RPMS are LOW. No rev matching, unless RMP's are high, like when driving aggressive. I have had many manual transmission cars with no issues, and long clutch life. My Accord had 188,900 miles on the original clutch. Yea it was slipping at this point, but was still drivable. MY Civic Si has 137 thousand now original clutch. Down shift at low RPMs all the time on both cars.

[tjts1]

Here is how I tried to optimize injector off overrun on my manual Mercedes using megesquirted efi. The goal was to maximize my ability to coast with engine in gear and injectors turned OFF. Engine braking be damned, that's what the 4 pot calipers are for.

To go into overrun (injectors off):
TPS = 0% open
coolant > 60f
RPM > 1300

Once in overrun:
ERG is turned ON to help equalize the pressure between intake and exhaust

Exit overrun:
RPM < 1100
or
TPS > 0%

This seems to work pretty well for me. The EGR valve makes a big difference in how far I can coast. I was actually kind of surprised. Our other car which runs it's stock engine management will only go into overrun above 2000 rpm and coolant over 160f.

[Joenavy85]

when i drive my girlfriends car i coast to the red lights in gear (an automatic), it goes into DFCO relatively quickly, and when i see it's close to cutting the injectors back in i push the O/D button to force it down into 3rd, then down into second gear as it slows more, i can usually keep it in DFCO until i'm down around 20-25 MPH, and after a little practice i figured out how far away to start the process at different speeds.