20-amp extension cord vs 15-amp extension cord: 20-amp is the safer choice for a 13-amp compressor

A 15-amp cord can technically handle 13 amps continuously if short and heavy enough, but compressors have a startup surge that spikes 2–3 times running amps. The 20-amp cord (12 gauge minimum) gives you a safe buffer for longer runs and startup spikes, while a 15-amp cord risks tripping breakers, overheating, or voltage drop that can burn out the motor. The price difference is usually a few bucks — don’t risk ruining a compressor or starting a fire.