Do you need to use high octane gas in vortec engines built in the 1990s?
On what Vortec engine you are talking about. The vast majority do not require the use of Premium fuel. Use exactly what your owner’s manual lists. Using Premium in an engine designed to run on Regular is a waste of money and provides no benefit whatsoever. No more power, no better mileage, nothing! Anyone who tells you different is buying into the myth, and that is all it is, a Myth. But if the engine requires Premium then use Premium. Using Regular in an engine designed for premium will cause engine damage due to what is commonly called pinging.
