diff --git a/Documentation/User Manual/1-user-interface/H_GBX-Editor.md b/Documentation/User Manual/1-user-interface/H_GBX-Editor.md
index ea4460b22f916dd9ede10c4684676819be6bb3d7..1ac895d63fa80333e23696910422d3010b3425e4 100644
--- a/Documentation/User Manual/1-user-interface/H_GBX-Editor.md	
+++ b/Documentation/User Manual/1-user-interface/H_GBX-Editor.md	
@@ -2,7 +2,7 @@
 
 
 
-![](pics/GBX-Editor.jpg)
+![](pics/GBX-Editor.png)
 
 
 ###Description
diff --git a/Documentation/User Manual/3-simulation-models/GearShift_AT.md b/Documentation/User Manual/3-simulation-models/GearShift_AT.md
index 366c86736e822fe969a824f927032bbd766fe189..bdf01ed4ecbad26e521489ffd853d87eddd1e67c 100644
--- a/Documentation/User Manual/3-simulation-models/GearShift_AT.md	
+++ b/Documentation/User Manual/3-simulation-models/GearShift_AT.md	
@@ -9,12 +9,14 @@ Gears are shifted sequentially:
 
 ###Upshift rules
 
-+ If engine speed in the next gear (see shift sequence) is above the upshift line AND
-+ The engine can provide at least the same power as currently required (i.e., can keep the current acceleration)
++ If engine speed and engine torque in the next gear (see shift sequence) is above the upshift line AND
++ the acceleration in the next gear is above a certain threshold if the driver is accelerating, i.e., acceleration_nextGear > min(Min. acceleration threshold, Driver acceleration)
+
+The user interface allows to enter two acceleration thresholds, one for locked gear to locked gear shifts and another vor converter to locked gear shifts. For converter to converter shifts the latter threshold applies.
 
 ###Downshift
 
-* If the engine speed falls below engine's idle speed
+* If the engine speed falls below the downshift curve
 
 * Drivetrain in "Neutral" when either
    	- velocity < 5 km/h
@@ -24,4 +26,5 @@ Gears are shifted sequentially:
 ###Shift parameters
 
 - Min. time between two consecutive gearshifts.
-
+- Min. acceleration after gearshift for L to L gear shifts
+- Min. acceleration after gearhsift for C to L (and C to C) gear shifts
diff --git a/Documentation/User Manual/3-simulation-models/Gearbox_AT.md b/Documentation/User Manual/3-simulation-models/Gearbox_AT.md
index c42ebfe197d630b3769125d08f946fc20e67c64d..f7857384eb2c06063b789e76033d87edc1eeec64 100644
--- a/Documentation/User Manual/3-simulation-models/Gearbox_AT.md	
+++ b/Documentation/User Manual/3-simulation-models/Gearbox_AT.md	
@@ -14,3 +14,27 @@ For AT gearboxes using power split the torque converter characteristics already
 
 The .vmod file for vehicles with AT gearboxes contains an additional column that indicates if the torque converter is locked or not.
 
+###Gearshift losses for AT Gearboxes
+
+For AT gearboxes the losses during a power-shift are modeled according to the following equations
+
+####Basic assumptions
+
++ Only power-shifts with positive power at gearbox output side are considered. 
++ Both upshifts and downshifts with positive power at gearbox output side have to be considered.
++ The power at gearbox output side is assumed to be constant during a power-shift
+
+
+####Power-shift loss computation
+
+Model parameters: shift time ($t_s$), inertia factor ($f_I$)
+
+![Engine speed, clutch speed during power-shift](pics/powershiftlosses.png)
+
+$T_{PS,loss} = |(T_{GBX,in} + T_{inertia}) * \Delta\omega_F| * t_s / dt$
+
+$T_{inertia} = f_I * I_{engine} * \Delta\omega_I / dt$
+
+$\Delta\omega_I = \omega_{engine,1} - \omega_{engine,2}$
+
+$\Delta\omega_F = (\omega_{engine,1} - \omega_{engine,1^*}) / 2$
diff --git a/Documentation/User Manual/pics/powershiftlosses.png b/Documentation/User Manual/pics/powershiftlosses.png
new file mode 100644
index 0000000000000000000000000000000000000000..e148f1770572e4e78f84f577fc8823772ea6fc79
Binary files /dev/null and b/Documentation/User Manual/pics/powershiftlosses.png differ