On 6/6/2018 11:50 PM, Bill wrote:
John H. wrote:
On Wed, 6 Jun 2018 15:49:36 -0400, "Mr. Luddite" wrote:

On 6/6/2018 12:35 PM, John H. wrote:
On Wed, 6 Jun 2018 06:59:53 -0400, "Mr. Luddite" wrote:



Those Jake brakes are really obnoxious, ought to be totally outlawed
in my opinion.


They are loud but you have to remember that a diesel, unlike a gasoline
engine, does not provide any engine braking when you take your foot
off the gas/fuel pedal. Going down a hill a diesel powered truck will
just keep accelerating and truckers would be replacing expensive brakes
often.



In 'tow/haul' mode, mine will downshift to slow down if I have the
cruise control at a slower speed.
Also, going downhill and hitting the brakes will cause it to downshift.


I understand but still, a diesel offers no engine braking like a gas engine.


I haven't figured out how it works, but the engine RPM goes up as the
truck is slowing down -
without me using the brake. It sure sounds and feels like the engine is
slowing the truck down
somehow.

Changes valve timing I understand. Makes it more a compressor. And the
fuel is shut off.



It works with the turbocharger. Transmission downshifts, increasing
engine RPM which increases turbo PSI. It's an "exhaust"
brake but not the same as a Jake brake used in large trucks.