If you have a recipe that calls for 1/2 cup of milk and you only have a litre measuring cup?
Or you should set you oven to 350 F but your oven only goes to 200 C?
Or you Harley manual tells you to torque to 80 inch lbs and your torque wrench reads in Nm?
Or you manual tells you to put 32 PSI in youtr tire...you go to the gas station and the tire guage reas in BAR?
You want to figure out your gas milage to compare with other members of the forum, your OD reads in miles and your gas pump reads in litres, but you wanna know MPG?
There is actualy something happening outside of the US borders. Americans are not the only ones on the planet, however comments like yours make us sound arrogant. We need to get up to speed, dump the SAE system and convert everything to the metric system like the rest of the world. It makes more sense and is SOOOO much easier to understand.