My car requires premium gas, but I filled the tank with a lower grade gas, causing a knocking sound. I then put in an octane additive. How long does it take for the knocking to go away? – Brett Octane ...
With rising petrol pump prices, can I downgrade from the usual 95- and 98-octane fuel to 92-octane to cut cost? With the way petrol prices are spiking, there is good reason to consider cheaper, ...