Changelog v3.3
-Sound pack fully updated to 1.39.
-Added iSX Signature engine.
-Improved all the engines sounds.

 Changelog v3.2
-Added Detroit DD13-15-16 engine sound for the SCS new 49X WS model.
-Fixed the Cummins 444 keeping playing in the game menu.

Changelog v3.1:
-Added new engine sound Detroit Diesel 8V92. Samples are from Semi Sound Doctor.
-Added engine sound Detroit Diesel 60 series.
-Improved M11 and Cat 3406E engine brake and turbo sound.
-Improved Cummins 444 series engine sounds. Samples are from Semi Sound Doctor.
-Improved Paccar MX13 with new exhausts sounds.
-Fixed an error with the air gear and air brakes sounds due to updated beta.
-Added support for John Ruda's W900, Freigheliner FLB by Harven, and GTM Peterbilt 567.

What's that sound pack adds to the game?
This mod adds those engines and their sounds in the game:

-Cummins M11
-Cummins 444
-Caterpillar 3406E
-Paccar MX series
-Detroit 60 Series
-Detroit 8V92

Video showing the 6 engines sounds available for the moment.
Kenworth W900.
Kenworth T680.
Mack Anthem. (only iSX Signature).
Kenworth W990 GTM.
Kenworth T800 GTM.
Peterbilt 567 GTM.
Peterbilt 389 SCS version and Viper's last version for 1.37.
Peterbilt 579.
Peterbilt 387.
International Lonestar.
Freightliner FLB by Harven
Kenworth K100.
Volvo VNL (SCS).
WS 49X Series (new SCS truck).

Of course i know that many engines sounds are missing, but i prefer to take my time and convert them as good as possible, i already improved them since the 1.36 version of the game.
I'll convert the rest of the sounds in the upcoming weeks/months.

Link 3 updated tires sounds

Credits:
kriechbaum