That depends on what’s important to you, but always consider the power supply and the power of the compressor, which dictates inflation time. Smaller models run on their own batteries. Larger ones connect to your vehicle’s battery via the cigarette lighter, or, for the most power, directly to the vehicle’s battery via alligator clamps. Some models can also plug into wall outlets. Inflation times range from seconds to minutes, depending on the size of the tire and how much air it needs. Also, the less powerful the compressor, the more it may shut down to protect against overheating.