does a 1973 super beatle volkswagon use unlead or preium gasoline

A HUGE marketing research study, Optimized chemical mechanism for combustion, the MIT researchers deemed AKI — and more specifically, MON — to be an outdated measure of engine performance, originally designed to apply to older, carbureted engines rather than modern, fuel-injected engines. To bring the octane rating system up to date, the team considered doing away with MON, and basing engine performance solely on RON. " Virtually nothing is gained by filling up with a premium or more expensive grade of fuel than the vehicle manufacturer has recommended, the experts say. And many of the same experts explain that drivers may not lose much performance from their cars by using a lower grade of fuel than recommended by the car manufacturer. There is little difference in energy content of regular versus premium gasoline. They both contain about 111,400 British Thermal Units of energy per gallon. The price difference, however, between the fuel grades is anywhere from 20 cents to 40 cents, depending on where you live in the United States. The experts' consensus goes against the long-held belief by thousand of drivers who fill up with premium only, or on every third or fourth trip to the pump. The idea is to fill up with premium every so often to clean out the engines or rev up the performance of older engines. But according to the experts, this practice is like tossing quarters in a wishing well, since most engines are designed to operate on relatively low-octane regular unleaded gasoline."