A couple of things...
Jamie:
When you do an oil change on your cage or your bike or lawn mower what do you do with the used oil? I'm presuming that your environmental regulations are more stringently enforced than ours are (there are still folks around me that use, used motor oil for dirt road dust control

) and is the oil more costly to buy? I also presume that your gasoline is more expensive and that you purchase liquids in metric measures?