diff --git a/README.md b/README.md
index 5deb46c..8309359 100644
--- a/README.md
+++ b/README.md
@@ -246,6 +246,7 @@ optional arguments:
   -m CAR             number of car model
   -vv, --verbose     show parameter explanations
   -e ECUID           index of ECU, or comma separeted list for DEMO MODE
+  -e CAR             number of car model for DEMO MODE
   --si               try SlowInit first
   --cfc              turn off automatic FC and do it by script
   --n1c              turn off L1 cache