Engine braking?

[Robobble]

OK, first off, I googled this for about 20 mins and all I could find was thousands of "Is engine braking bad for your engine, clutch, tranny, etc". Anyways. I just bought a brand new Fiesta (I LOVE it), it's got about 250 miles, and it is completely awful at engine braking. If I'm going down a moderate hill in 2nd gear, it would rev itself up to redline if I let it. Quickly, too. It doesn't even feel like it's trying to slow itself down. Maybe it's cause it's a little 1.6 (this is my first 4-banger, I'm used to V8s)? Or maybe it's just a low compression motor? I hope there isn't a problem with the piston rings sealing properly. Ideas?

[Reddog99]

Engine braking is an aid for controlling downhill speed. It is not supposed to be the absolute only method used. What I mean is that you need to use the brakes in addition to the engine.

The engine braking feature on the Fiesta Powershift works well on downhill grades, but the high revving engine which you experience is completely normal and to be expected. You have a lot of car pushing a little motor. Personally, I don't care for all the noise, so I don't use it a whole lot. I think that Ford may have over-done it a bit. And the Fiesta is not low compression, it has a 11:1 ratio, which is really quite high.

[Robobble]

First off, it's a manual. Sorry for not specifying. Every manual I've driven will put considerable effort into stopping itself with your foot off the gas at 4500 RPMs lol. All I'm saying is that level of engine braking that I'm used to isn't there with this car. The last mustang I had would hold itself at a steady speed without much engine fuss (maybe 3500rpm) on pretty steep hills with no brakes at all. My question was why some cars speed can be more easily controlled by downshifting than others.

[macus]

If you think about it, your mustang was compressing air in 8 cylinders to slow you down, while in the Fiesta it's only 4 -- a lot less resistance to piston movement.

There is more wear when engine braking, but it's normally miniscule. On the other hand, decelerating shuts off the fuel injectors in most cars nowadays, so you're also saving a bit of gas by engine braking.

[archenok]

I seem to recall that there's some sort of programming in this ECU that prevents abrupt engine braking when lifting off at high rpms.

Also, when I used to have a manual 4 banger and wanted some real engine braking I would actually let the revs drop nearer to idle first and then ease the clutch back in. That way there's additional engine braking just from spooling the revs back up. Sometimes that move alone is enough to slow the car down to the speed I want to go and hold it. I can't do this in the powershift (no clutch pedal).

But I am agreed on the weaker engine braking. The downhill assist would sometimes drop down two gears instead of one when all I wanted was to drop one gear to help the brakes. It does revmatch nicely to achieve a smooth downshift but I end up going the same speed as before the double down shifts with the revs high and not much slowdown from the whole move.

[kabukiman]

use the brake pedal instead

Also like someone else said I thought these motors were relatively high compression


The powershift version engine brakes pretty well, but only when you lightly use the pedal too. Otherwise it just shuts off the injection and rolls, which is great for fuel economy

[aspitaletto]

Originally Posted by Robobble

All I'm saying is that level of engine braking that I'm used to isn't there with this car.


The last mustang I had would hold itself at a steady speed without much engine fuss (maybe 3500rpm) on pretty steep hills with no brakes at all. My question was why some cars speed can be more easily controlled by downshifting than others.

Hey meng, its a 1.6L engine, 4Cly, not a 5.0L V8

[iamz]

I have a pretty steep hill with an over twohundred foot elevation drop into the river valley I live in. If I'm driving at 50 mph and let off the gas, the car will maintain almost an exact 50 mph all the way down and stay just over 2000 rpm. If I pop it into neutral, it will be at 60 about half way down.

So at least for my car, with the Powershift tranny, engine braking is fine. It's strange that your manual will redline.

[telero]

I don't know that I would use this engine to actually do the braking. Using the engines resistance to keep you at a lower speed is one thing, using it to slow the vehicle is another. From my understanding it's good to use the engine to control the downhill speed so you don't continually use the brakes and overheat them, causing them to be less effective when needed. But you could still use the brakes to more quickly slow yourself to the appropriate speed, then select the appropriate gear to maintain that speed.

[Norm201]

Originally Posted by telero

I don't know that I would use this engine to actually do the braking. Using the engines resistance to keep you at a lower speed is one thing, using it to slow the vehicle is another. From my understanding it's good to use the engine to control the downhill speed so you don't continually use the brakes and overheat them, causing them to be less effective when needed. But you could still use the brakes to more quickly slow yourself to the appropriate speed, then select the appropriate gear to maintain that speed.

Agreed. When encountering a steep down hill at a relative high speed (40-60 MPH) I'll hit the brake intermittently and if need be down shift or use hill assist. I'll agree that when using the engine to assist braking it's a bit unnerving to hear and see the RPM's go up and/or past 4000. The main thing is keep the brake pads cool enough and not let the brake fluid go into a boil mode thereby causing lose of braking power. But even more important to me is avoiding the high heat produced from using the brake too much and causing disk warpage.