[thackney]

Yes, the autoignition (pre-ignition) in spark-ignition engines is called knocking. It will cause excessive wear on an engine over time.

It was not a significant issue until manufactures started producing higher compression engines that made the condition more prevalent.

[X-spurt]

Growing up in the East Texas Oil Patch, remembering how easy it was to get “drip or casenhead” gas which knocked like heck, and was definately not good for your engine, but couldn’t beat the price (when gas stations were selling Regular for 25cents). Basically was natural gasoline or unlead. Was great in Coleman lanterns and stoves.

Thanks for the Tech lesson today!