Engines sizes are typically listed in liters. The engine size will be listed in your owners manual and on the emission decal located in the engine compartment. The emissions decal is generally placed on any flat well exposed surface in the engine compartment.
There is no standardized emission decal, however they are typically white with black text.
If your engine size is not listed in the pull-down menu, please select "OTHER", and then enter the engine size. For example: 2.4
Emission decal example:
