[BC_Dan]

Heat range is the same, but the non-resistor plug can mess with the ECU. Best to use the 'BR' plug if it's got electronic ignition.

 

[BC_Dan]

yes

CDI stands for Capacitor Discharge Ignition which is very common on small, fast-revving engines such as motorcycles, snowmobiles, chainsaws, lawnmowers, etc.

 

[BC_Dan]

The octane rating system was developed in 1931, the current system is a combination of two different tests, the Motor Method and the Research Method. There have been few significant changes in the methods, what did change about 1980 was tetra-ethyl lead was no longer allowed to increase the octane rating of the fuel. The number we see at the pump is the Motor Octane Number (MON) + Research Octane Number (RON) divided by 2.

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