My guess is since the fuel tank opening is on the left side and most people fail to set the parking brake besides leaving the truck in gear during a stop. There have been some roll back incidents catching a gas pump. Or gate post, or garage door edge, etc, etc. My first vehicle was a 1950 Chevy truck, and since it was 30 years old at the time; park brake didnt work and as a young lad was a bit too lazy to bother fixing it
