In the U.S., the emissions limit for carbon monoxide in motorcycle engine exhaust is 12.0 g CO per km driven. What is this limit expressed in milligrams per mile (mg/mi)?
This sounds like an old routine where the speed of light was expressed with the units," furlongs per fortnight ". There are 12,000 mg in 12 g, and 0.6213 miles in a km.
1 km = 0.6213 miles.
I'm sorry to have abbreviated mile to