efficiency

cooking with gas Operating at maximum efficiency; performing well, functioning smoothly; really in the groove or on the right track. The expression probably comes from the efficiency of gas as a cooking medium (as contrasted with coal, wood, kerosene, electricity, etc.). Occasionally the phrase is jocularly updated by variants such as cooking with electricity or cooking with radar.

hit on all six To run smoothly; to function properly; to work to one’s fullest capacity; to be in physically fit and trim condition. This Americanism was originally used in speaking of internal combustion engines, specifically the functioning of the cylinders, which often misfired in earlier cars. When the figurative use gained currency, the word cylinder was dropped from the end of the expression. Variants include hit on all four and other multiples of two.

in the groove In full swing, functioning smoothly, in top form. This U.S. slang expression was coined in the jazz age. Groove originally referred to the grooves of phonograph records. In the 1930s and ’40s, in the groove meant to play jazz music fervently and expertly, or to appreciate such music and by association be considered “hep” and sophisticated.

Eventually in the groove and groovy grew to mean ‘up-to-date’ or ‘fashionable,’ although this use is now being phased out of current slang. When in the groove is used, as in the following quotation from Webster’s Third, it emphasizes the quality of being in top form, rather than sophistication or fashionableness.

just like New York This American slang expression, usually an isolated comment on successful performance, has a wide range of equally vague equivalents such as right on, great, nice going, way to go. The reference is to New York City as the epitome of success, society, and fashion.