Impact wrenches are one of the most commonly associated tools with changing tires. You can probably imagine the familiar muffled whirring sound that you often hear at your local tire shop. Beyond wheel and tire work, impact wrenches can be very useful for most types of automotive work, particularly on larger bolts that would otherwise be taxing to remove using arm strength alone. The uses for an impact wrench are seemingly endless in the automotive world, however there are a lot of choices in terms of torque output, speeds, and power sources. One of the most common questions we get asked is whether to choose air power (driven by an air compressor) or electric power (driven by 120V current from a wall outlet). When it comes to the problem of choosing a corded versus an air powered impact wrench, both have strengths and weaknesses that lend well to certain situations more so than others. In this article, we have highlighted some of the strengths and weaknesses in order to compare air powered to electric impact wrenches.
Corded Impact Wrenches
Perhaps one of the best attributes of an electric impact wrench is that as long as you have a power outlet available, they will pretty much run continuously. There are no concerns of air pressure drop or compressor fill time that you would typically encounter on air powered impact tools when used continuously for an extended period of time. Another advantage is that you can pretty much use them anywhere without any additional setup, meaning you don’t have to worry about an air compressor and associated components. This means you can lend it to a friend or bring it to your parent’s house to help with a garage project and everyone will be able to use it without special equipment.
One of the main disadvantages of corded impact tools is the limited reach of the cord. These cords will typically be less than ten feet long, but generally they won’t be long enough to reach from the wall outlet to all parts of your work area. This will require a heavy-duty extension cord that can be a trip hazard and add extra cost to your purchase if you don’t already have an extension cord. The extra expense of an extension cord can be even more frustrating because corded impact wrenches are already on the expensive side; they are significantly more expensive than air powered wrenches (excluding the cost of a compressed air system). One final potential sticking point is that corded impact wrenches can be pretty power hungry, so if you live with a garage with an easily tripped fuse box, you may find it easy to overwhelm your circuits if you have other tools or appliances drawing power simultaneously.
Air Powered Impact Wrenches
Pneumatic (compressed air) impact tools are pretty common in their use in the home garage, but even more so in professional mechanic shops. They come in variety of shapes and sizes to accommodate almost any car repair work you could dream up. With a quick search you can find some inexpensive high quality air tools, and with simple maintenance mainly consisting of visual inspection and application of pneumatic tool oil they will last a long time in your garage. Perhaps the biggest advantage, assuming you have a functional air system in place in your garage, is that pneumatic impact tools are extremely cheap versus their electric counterparts. Another huge advantage is that there are no electronics that can malfunction, so you are relying on a purely mechanical system which translates into extremely high reliability so long as you use a drop or two of oil each time you connect the air hose.
The biggest and most obvious downside to pneumatic tools is their requirement for compressed air. If you have a compressor in the garage already, you are ahead of the curve. However if not, an air system can become a very costly endeavor (and admittedly probably not worth it unless you intend to power many air tools with it). Another slight downside is that air impact wrenches require a little bit more due diligence when it comes to maintenance in that you must be religious about oiling them to keep them operating smoothly.
Corded and pneumatic impact wrenches perform identical functions and the only major difference is the power supply. Similar tools with similar torque ratings can be had for both air powered and electric wrenches that cover pretty much every car related application. They are also both available in every drive size so they will fit pretty much any set of impact sockets or impact extensions you can throw at them. As both of these two wrench types are also tethered to the wall via either a cord or a hose, the biggest deciding factor is overall cost, which largely depends on your existing tool setup.
If you already have compressed air routed in your garage, air powered impact tools make a ton of sense because they are extremely cost effective in this case. If you are starting fresh and don’t have any of the required air infrastructure (air hoses, a compressor, etc.), we suggest keeping it simple and sticking with a corded impact wrench. If you want to check out some air and corded impact wrench recommendations, click here to read through our impact wrench buyer’s guide. Happy wrenching!