[roelschroeven]

> With no throttle plate, the remaining mechanical components in a diesel engine provide minimal friction, certainly not enough to produce any brake effect.

I don't understand. I've driven multiple diesel engine cars throughout the years, and they most definitely have a brake effect. I'm not even sure they brake less than the gasoline cars I've driven. Easily enough to slow down for taking an exit from the freeway, for example, when shifting down appropriately. To the point that there regularly are situations when I lightly press the brake pedal not to brake but to simply light the brake lights, if there are cars behind me.

It does sound plausible that the lack of a throttle leads to less or no brake effect, but it simply doesn't fit my observations.

I'm talking about regular cars here, both recent and less recent (the oldest one was built in 1989).

Maybe there are different diesel engine types with different brake capabilities? Or do some gasoline engines brake much more than what I'm used to, and my reference for what is and isn't significant braking is all wrong?

[mcguire]

https://www.youtube.com/watch?v=o8Cta2cC2Co

https://en.wikipedia.org/wiki/Engine_braking#Diesel_engines

[pwg]

See @ska's comment at https://news.ycombinator.com/item?id=30195348