Why do modern diesel cars have so little engine braking?

[johnnyrod]

We have a few pool cars at work and they all go for miles when you take your toe off the throttle, why is that? My pickup has a CRTD engine and, a bit like the SV, "half" the time you don't need the brakes.

[G]

Because engine braking is uneconomical.

[punyXpress]

At about 1000rpm the fuel meter will bleed into the system so the revs will not drop any lower?
Since air is free to enter the cylinders pumping losses are a lot lower than petrol engines.

[mikerj]

Because engine braking is uneconomical.

Why would you think that? :confused: A common rail engine will work just like an injected petrol on over-run conditions; fuel will be completely cut until a certain rev limit is reached.

The very high final drives used for economy, combined with heavy dual mass flywheels significantly lower engine braking effort.

[Reeder]

I've found too that my little diesel will coast for fecking ages. It's as if there's barely any engine braking what so ever!

[toxic]

Lighter fly wheel?

[mikerj]

Heavier flywheel = more resistant to changes in speed.

[johnnyrod]

Okay perhaps I phrased the question wrongly. Why does my pickup have masses of engine braking when a car doesn't? Does the engine do something differently?

[mikerj]

Okay perhaps I phrased the question wrongly. Why does my pickup have masses of engine braking when a car doesn't? Does the engine do something differently?

Gearing? Engine size?