diff --git a/mazda/callbacks.cpp b/mazda/callbacks.cpp
index 3659aa9b..b24278d5 100644
--- a/mazda/callbacks.cpp
+++ b/mazda/callbacks.cpp
@@ -680,6 +680,7 @@ void MazdaEventCallbacks::HandleNaviTurn(IHUConnectionThreadInterface& stream, c
     changed = 1;
   }
   if(changed){
+    navi_data->changed = 1;
     navi_data->previous_msg = navi_data->previous_msg+1;
     if(navi_data->previous_msg == 8){
       navi_data->previous_msg = 1;
@@ -689,16 +690,23 @@ void MazdaEventCallbacks::HandleNaviTurn(IHUConnectionThreadInterface& stream, c
 }
 
 void MazdaEventCallbacks::HandleNaviTurnDistance(IHUConnectionThreadInterface& stream, const HU::NAVDistanceMessage &request){
-    hudmutex.lock();
-    if(request.distance() > 1000){
+  hudmutex.lock();
+  if(request.distance() > 1000){
+    int now_distance = request.distance()/100;
+    if(now_distance != navi_data->distance){
       navi_data->distance_unit = 3;
-      navi_data->distance = request.distance()/100;
+      navi_data->distance = now_distance;
+      navi_data->changed = 1;
     }
-    else{
+  }
+  else{
+    int now_distance = (((request.distance() + 5) / 10)*10)*10;
+    if(now_distance != navi_data->distance){
       navi_data->distance_unit = 1;
-      navi_data->distance = (((request.distance() + 5) / 10)*10);
-      navi_data->distance = navi_data->distance*10;
+      navi_data->distance = now_distance;
+      navi_data->changed = 1;
     }
-    navi_data->time_until = request.time_until();
-    hudmutex.unlock();
+  }
+  navi_data->time_until = request.time_until();
+  hudmutex.unlock();
 }
diff --git a/mazda/hud/hud.cpp b/mazda/hud/hud.cpp
index 55627af7..cef07b11 100644
--- a/mazda/hud/hud.cpp
+++ b/mazda/hud/hud.cpp
@@ -88,17 +88,18 @@ void hud_thread_func(std::condition_variable& quitcv, std::mutex& quitmutex, std
     guidancePointData._1 = navi_data->event_name;
     guidancePointData._2 = navi_data->previous_msg;
 
-
-
-    try
-    {
-      vbsnavi_client->SetHUDDisplayMsgReq(hudDisplayMsg);
-      tmc_client->SetHUD_Display_Msg2(guidancePointData);
-    }
-    catch(DBus::Error& error)
-    {
+    if(navi_data->changed){
+      try
+      {
+        vbsnavi_client->SetHUDDisplayMsgReq(hudDisplayMsg);
+        tmc_client->SetHUD_Display_Msg2(guidancePointData);
+      }
+      catch(DBus::Error& error)
+      {
         loge("DBUS: hud_send failed %s: %s\n", error.name(), error.message());
         return;
+      }
+	  navi_data->changed = 0;
     }
     hudmutex.unlock();
     {
diff --git a/mazda/hud/hud.h b/mazda/hud/hud.h
index 102c9882..47639a46 100644
--- a/mazda/hud/hud.h
+++ b/mazda/hud/hud.h
@@ -20,6 +20,7 @@ struct NaviData {
   uint8_t distance_unit;
   int32_t time_until;
   uint8_t previous_msg;
+  uint8_t changed;
 };
 
 enum NaviTurns: uint32_t {