Should I buy cordless or air impact wrenches?
Short answer: Cordless tools win on portability and convenience, while air tools are lighter for their power, cheaper per tool and run all day if you have enough compressed air; many shops use both.
Cordless impact wrenches have improved enormously and now handle much of the work air tools used to do. They go anywhere without hoses, which helps in road service, mobile repair and crowded bays. The trade-off is battery cost, battery weight and charge management.
Air impact wrenches are lighter for a given power level, generally simpler mechanically, and can run continuously, but they need a compressor that keeps up, plus hoses, couplers and regular oiling. A small compressor that cannot supply enough air leaves the tool short of its rated performance.
If you already have a good air system, air tools are cost-effective. If you are building a mobile setup, cordless makes sense. Many technicians use cordless for convenience and keep heavy air tools for big jobs. Wear eye and hearing protection with any impact tool.
Tools used for this job
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.