Mark and Kim Smith wrote:
Mike Marron wrote:
(Peter Stickney) wrote:

Allison also Diesel engines for use in tractor-trailers & other such
applications. You can easily pick 'em out by ear, they've got a
distinctive high-frequency scream in their engine note.

I'm not aware of any Allison diesel engines used in semis. The Big
Three truck engine manufacturers are Caterpillar, Cummins and Detroit
Diesel. Going down the road, you can't differentiate between the three
by the sound alone and I suspect the high-freqency scream you're
referring to is simply the turbo.

Stick International in there. You can't look out your car window
without seeing something powered by a DT466E.

Most International over-the-road chassis' have either a Cat, Detroit
Diesel or Cummins under the hood. Mack produces their own engines
and trannys as well, but they're still not as commonly used in big,
OTR rigs as the three manufacturers I mentioned above.

Yup, no such animal as an Allison diesel. But plenty of World
transmissions! As far as noise, you can tell a 6V-8V 92 from others,
but that's because it's big, dirty and ugly! Most days now though,
the manufacters make all of them sound like purring kittens! Until
that Jake Brake wakes you up in the middle of the night.

Except when negotiating mountain passes like those treacherous
grades found on I-70 (west of Denver and in Utah), Donner pass in
Calif, Monteagle in Tenn, etc. I rarely if ever used the Jake brake
out of courtesy for the motoring public.