There are two grades of pellet fuel currently available on the market: standard and premium grades.

在市场上有目前可提供的小球燃料有二个等级： 标准和高级。

youdao

An essential difference between "premium" and "regular" grades of kerosine is that the former has a higher smoke-point.

“高档”与“中档”煤油的根本差别在于前者比后者的发烟点高。

youdao

Similarly, Gas Buddy and Local Gas Prices can come in handy to help locate the cheapest gas prices in a given area for regular, midgrade, premium and diesel grades.

FORBES: Free iPhone Apps to Help Lower Your Car's Fuel Costs