Would premium gas harm your 1974 super beetle?

Premium gasoline would not likely harm your 1974 Super Beetle. However, it would be unnecessary and would not provide any benefit over using regular gasoline with an octane rating of 87. The original 1974 Super Beetle was designed to run on regular unleaded gasoline with an octane rating of 87. Using premium gasoline with a higher octane rating than 87 would simply be wasting money as the engine is not designed to take advantage of the higher octane fuel.

Octane ratings measure the resistance of fuel to resist knocking. Higher octane fuels are more resistant to knocking and are designed for higher compression engines. Knocking occurs when the fuel ignites too quickly in the engine, causing a pinging or knocking sound. The compression ratio of the 1974 Super Beetle engine is designed to use unleaded gasoline with an octane rating of 87. Using higher octane fuel will not provide any benefit and may actually cause problems with the engine.

In addition, using premium gasoline in your 1974 Super Beetle may void the warranty on your vehicle. It is always best to refer to your owner's manual or consult with your mechanic to determine the best type of fuel for your vehicle.