Technician A says that using lower octane fuel in vehicles designed for premium fuel, will cause serious engine damage. Technician B says that some octane boosters will cause discoloration of the porcelain on the spark plug tip. Which technician is correct?

Technician B only is correct and Technician A is wrong

Explanation:

Technician B only is correct and Technician A is wrong because

using lower octane fuel will only affect the power and does not damage the engine and some octane booster will discolor porcelain on the spark plug.

Octane number is figure indicating the antiknock properties of a fuel based on comparison with the mixture of isooctane and n-heptane

Hence we can say that Technician B only is correct and Technician A is wrong