"vital engine" is a correct and usable phrase in written English.
You can use it to refer to a driving force or primary catalyst that helps something to flourish. For example, "Wisdom is the vital engine that will drive our company's success."
Policymakers are desperate to get more credit flowing to this vital engine of economic growth.
BAT and its competitors are determined to do all they can to prevent the final dismantlement of its vital engine.
software controls vital engine functions like ignition timing and fuel mixture, and will be adjustable within Nascar-defined limits.
The entrepreneurial pursuit of profitable growth has been the vital engine of prosperity since the Industrial Revolution.
The C.D.O. business has been a vital engine in the money machine at many firms for much of the last decade.
Rather, they want the Internet to become a vital engine of national progress, harnessed wherever necessary to the controlling forces of the state.
With America stuck in slow growth, Europe mired in stagnation and the Arab world imploding, China has been a vital economic engine for the global economy.
Howard Dean and Richard A. Gephardt on Friday withdrew harsh television advertisements attacking each other, switching instead to sharp but indirect new assaults accusing their Iowa caucus rival John Kerry of failing to support some federal subsidies for agriculture, Iowa's vital economic engine.
A1 Democrats Attack Kerry in Iowa Howard Dean and Richard A. Gephardt withdrew ads attacking each other in favor of new assaults accusing their Iowa caucus rival John Kerry of failing to support some federal subsidies for agriculture, the state's vital economic engine.
With the satanic Born still at large, a desperate need to know – that primitive but vital fictional engine – sends the reader scurrying to a conclusion that is more satisfying in terms of its ideas than its emotional resolution.
The Detroit Free Press on Thursday endorsed Mitt Romney, bit did so while chiding him for his opposition to granting federal aid to automakers during the financial crisis: "Romney was also dead wrong when he opposed government bailouts for the auto industry (Michigan's most vital economic engine) in late 2008.
