diff --git a/Tools/autotest/pysim/sim_multicopter.py b/Tools/autotest/pysim/sim_multicopter.py
index 8db810f7bb..42058a67ee 100755
--- a/Tools/autotest/pysim/sim_multicopter.py
+++ b/Tools/autotest/pysim/sim_multicopter.py
@@ -101,7 +101,7 @@ parser.add_option("--rate", dest="rate", type='int', help="SIM update rate", def
 parser.add_option("--wind", dest="wind", help="Simulate wind (speed,direction,turbulance)", default='0,0,0')
 parser.add_option("--frame", dest="frame", help="frame type (+,X,octo)", default='+')
 parser.add_option("--gimbal", dest="gimbal", action='store_true', default=False, help="enable gimbal")
-parser.add_option("--nowait", action='store_true', help="don't pause between updates")
+parser.add_option("--speedup", type='float', default=1.0, help="speedup from realtime")
 
 (opts, args) = parser.parse_args()
 
@@ -169,6 +169,7 @@ print("Starting at lat=%f lon=%f alt=%.1f heading=%.1f" % (
     a.yaw))
 
 frame_time = 1.0/opts.rate
+scaled_frame_time = frame_time/opts.speedup
 
 if opts.gimbal:
     from gimbal import Gimbal3Axis
@@ -192,8 +193,8 @@ while True:
     sim_send(m, a)
 
     now = time.time()
-    if not opts.nowait and now < last_wall_time + frame_time:
-        time.sleep(last_wall_time+frame_time - now)
+    if now < last_wall_time + scaled_frame_time:
+        time.sleep(last_wall_time+scaled_frame_time - now)
     last_wall_time = time.time()
 
     a.time_advance(frame_time)
diff --git a/Tools/autotest/pysim/sim_rover.py b/Tools/autotest/pysim/sim_rover.py
index 921ff5392c..f4e09b696a 100755
--- a/Tools/autotest/pysim/sim_rover.py
+++ b/Tools/autotest/pysim/sim_rover.py
@@ -79,7 +79,8 @@ parser.add_option("--simout", dest="simout",  help="SIM output (IP:port)",
 parser.add_option("--home", dest="home",  type='string', default=None, help="home lat,lng,alt,hdg (required)")
 parser.add_option("--rate", dest="rate", type='int', help="SIM update rate", default=1000)
 parser.add_option("--skid-steering", action='store_true', default=False, help="Use skid steering")
-parser.add_option("--nowait", action='store_true', help="don't pause between updates")
+parser.add_option("--speedup", type='float', default=1.0, help="speedup from realtime")
+
 
 (opts, args) = parser.parse_args()
 
@@ -132,6 +133,8 @@ print("Starting at lat=%f lon=%f alt=%f heading=%.1f" % (
     a.yaw))
 
 frame_time = 1.0/opts.rate
+scaled_frame_time = frame_time/opts.speedup
+
 last_wall_time = time.time()
 
 counter = 0
@@ -149,8 +152,8 @@ while True:
     sim_send(a)
 
     now = time.time()
-    if not opts.nowait and now < last_wall_time + frame_time:
-        time.sleep(last_wall_time+frame_time - now)
+    if not opts.nowait and now < last_wall_time + scaled_frame_time:
+        time.sleep(last_wall_time+scaled_frame_time - now)
     last_wall_time = time.time()
 
     a.time_advance(frame_time)
diff --git a/Tools/autotest/sim_vehicle.sh b/Tools/autotest/sim_vehicle.sh
index 5e544bd12f..5241b56b9a 100755
--- a/Tools/autotest/sim_vehicle.sh
+++ b/Tools/autotest/sim_vehicle.sh
@@ -7,6 +7,7 @@ VEHICLE=""
 BUILD_TARGET="sitl"
 FRAME=""
 NUM_PROCS=1
+SPEEDUP="1"
 
 # check the instance number to allow for multiple copies of the sim running at once
 INSTANCE=0
@@ -48,6 +49,7 @@ Options:
     -j NUM_PROC      number of processors to use during build (default 1)
     -H               start HIL
     -e               use external simulator
+    -S SPEEDUP       set simulation speedup (1 for wall clock time)
 
 mavproxy_options:
     --map            start with a map
@@ -64,7 +66,7 @@ EOF
 
 
 # parse options. Thanks to http://wiki.bash-hackers.org/howto/getopts_tutorial
-while getopts ":I:VgGcj:TA:t:L:v:hwf:RNHeM" opt; do
+while getopts ":I:VgGcj:TA:t:L:v:hwf:RNHeMS:" opt; do
   case $opt in
     v)
       VEHICLE=$OPTARG
@@ -107,6 +109,9 @@ while getopts ":I:VgGcj:TA:t:L:v:hwf:RNHeM" opt; do
     f)
       FRAME="$OPTARG"
       ;;
+    S)
+      SPEEDUP="$OPTARG"
+      ;;
     t)
       TRACKER_LOCATION="$OPTARG"
       ;;
@@ -171,39 +176,43 @@ set -x
 EXTRA_PARM=""
 EXTRA_SIM=""
 
+[ "$SPEEDUP" != "1" ] && {
+    EXTRA_SIM="$EXTRA_SIM --speedup=$SPEEDUP"
+}
+
 # modify build target based on copter frame type
 case $FRAME in
     +|quad)
 	BUILD_TARGET="sitl"
-        EXTRA_SIM="--frame=quad"
+        EXTRA_SIM="$EXTRA_SIM --frame=quad"
 	;;
     X)
 	BUILD_TARGET="sitl"
         EXTRA_PARM="param set FRAME 1;"
-        EXTRA_SIM="--frame=X"
+        EXTRA_SIM="$EXTRA_SIM --frame=X"
 	;;
     octa)
 	BUILD_TARGET="sitl-octa"
-        EXTRA_SIM="--frame=octa"
+        EXTRA_SIM="$EXTRA_SIM --frame=octa"
 	;;
     octa-quad)
 	BUILD_TARGET="sitl-octa-quad"
-        EXTRA_SIM="--frame=octa-quad"
+        EXTRA_SIM="$EXTRA_SIM --frame=octa-quad"
 	;;
     heli)
 	BUILD_TARGET="sitl-heli"
-        EXTRA_SIM="--frame=heli"
+        EXTRA_SIM="$EXTRA_SIM --frame=heli"
 	;;
     elevon*)
         EXTRA_PARM="param set ELEVON_OUTPUT 4;"
-        EXTRA_SIM="--elevon"
+        EXTRA_SIM="$EXTRA_SIM --elevon"
 	;;
     vtail)
         EXTRA_PARM="param set VTAIL_OUTPUT 4;"
-        EXTRA_SIM="--vtail"
+        EXTRA_SIM="$EXTRA_SIM --vtail"
 	;;
     skid)
-        EXTRA_SIM="--skid-steering"
+        EXTRA_SIM="$EXTRA_SIM --skid-steering"
 	;;
     obc)
         BUILD_TARGET="sitl-obc"
@@ -219,7 +228,7 @@ esac
 
 if [ $USE_MAVLINK_GIMBAL == 1 ]; then
     echo "Using MAVLink gimbal"
-    EXTRA_SIM="--gimbal"
+    EXTRA_SIM="$EXTRA_SIM --gimbal"
 fi
 
 autotest=$(dirname $(readlink -e $0))