Thought I'd share some info that is not commonly known:-
Winch
In the US winches are rated by lbs/weight they will pull on 1st layer of cable, Tatra uses force which is not 100% interchange because it's mass/accel ie kg mass x m per second, so you would have to test US winch via EU std, also I found Tatra list force KN on last layer of line which considerably reduces its pulling force, long story short after seeing winch manual where it lists 1st layer line pull and using a basic formula the Tatra winch is basically equivalent to a US 45,000 lbs Braden / Tulsa winch. This is same for 813 & 815.
TP6 model:-
Where as other model 813 / 815 are selectable rear drive / engage front drive, TP models are AWD.
On 815 version only, VT 4 dr 8x8 and TP6's the engine is set back in the chassis enabling a semi flat floor for the drivers area v the normal dog house on all other 2 dr cabs, these engines required a semi remote oil pan + they have an additional stage sector on the oil pump and have a large oil sump capacity. Not only does this improve cab ergo's but improves weight distribution, particular important to the TP prime mover ballast tractor which increased its max GCWR to 120t or 265,000 lbs American v 100T for the 813 version.
Winch
In the US winches are rated by lbs/weight they will pull on 1st layer of cable, Tatra uses force which is not 100% interchange because it's mass/accel ie kg mass x m per second, so you would have to test US winch via EU std, also I found Tatra list force KN on last layer of line which considerably reduces its pulling force, long story short after seeing winch manual where it lists 1st layer line pull and using a basic formula the Tatra winch is basically equivalent to a US 45,000 lbs Braden / Tulsa winch. This is same for 813 & 815.
TP6 model:-
Where as other model 813 / 815 are selectable rear drive / engage front drive, TP models are AWD.
On 815 version only, VT 4 dr 8x8 and TP6's the engine is set back in the chassis enabling a semi flat floor for the drivers area v the normal dog house on all other 2 dr cabs, these engines required a semi remote oil pan + they have an additional stage sector on the oil pump and have a large oil sump capacity. Not only does this improve cab ergo's but improves weight distribution, particular important to the TP prime mover ballast tractor which increased its max GCWR to 120t or 265,000 lbs American v 100T for the 813 version.
at least the 813's are permanent AWD, maybe with the exception of some of the crazier job-specific versions. Since 815's are too modern (read: expensive) for me 
