Diesel engines have lots of Compression (hence the need for powerful
starting batteries) but this does NOT mean they have lots of compression
braking.
Most of the energy needed to compress the air in the cylinder gets
returned when the piston moves down (often called an Air Spring)
Having the throttle closed is what provides compression braking in a
gasoline powered car. Diesel do NOT have a throttle flap to close off the
air intake.
A "Jake Brake" is an ADD-ON to a diesel engine so that big rigs can get
some compression braking. The overwhelming majority of Diesel cars do NOT
have Jake Brakes. For the most part they rely on mechanical brakes.
As for EVs, I do agree that the brakes of a gasoline powered car /may/
need some improvement if you go down any long, steep hills. I'm just
pointing out that since diesel powered cars can get away with just
mechanical brakes, then electric powered ones can probably do the same.
I'm also pointing out that EVs do NOT generally go down long, steep hills,
because they generally can't climb long steep hills.
>>> Diesel powered cars have very little compression braking and seem to be
>>> able to descend hills safely.
>>
>> Huh? What? Diseasel cars compression brake just fine! Hell you
>> need a GP 27 battery to crank the damn things when it's cold! Of
>> course they go down hills great in low gear, like throwing out the
>> anchor!
>
> Yeah - isn't that what a "Jake brake" on a big rig is used for? Noisy
> as hell and not legal inside city limits, but they put that 15-25:1
> compression to work as an air pump through the exhaust!
>
> _______________________________________________
> For subscription options, see
>
http://lists.sjsu.edu/mailman/listinfo/ev>
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev
