One of the fun aspects of running a blog is helping our readers answer these little, nagging questions.
Twenty years ago, there were no major blogs, and the internet was much smaller. Cell reception was spotty.
As a result, you’d have to drive over to Grandpa’s house, pull up a rocking chair and a coffee, flip out your pocket knife and whittle away on a stick of wood while you asked him whether he’d rather have an impact driver or an impact wrench for changing his lug nuts.
In the spirit of the “good ole days,” you may as well pour yourself a cup of coffee while we dive into this.
An impact driver is smaller than an impact wrench. A good way to think of it is as an over-powered screwdriver.
What sets the impact driver apart from a screwdriver, is the internal hammering mechanism. When you are drilling screws into hardwood, this mechanism helps create more torque and provides a faster, more powerful, screwing mechanism.
This is especially handy when drilling holes. Even the smaller impact drivers are able to run a 1 inch boring bit into 8 inches of pine board.
A few years ago, this kind of cordless power simply didn’t exist.
The advantage of an impact driver is that you can use it for so much more than drilling. You can use it to drill, to sink screws and even for mechanical work on the car.
There are a lot of great tool reviews sites such as Tool Tally and Popular Mechanics that offer updated reviews on the specifications of these tools every year. However, an impact driver will never produce the raw torque that the wrench will.
Where the impact driver comes up short is that it is unable to match the insane power of an impact wrench.
For decades, pneumatic (air-powered) impact wrenches were the gold standard in the auto mechanic’s shop. These impact wrenches could deliver as much torque as a semi-truck engine, all concentrated into one lug bolt.
These are indispensable tools for the dedicated auto mechanic. Not only are they extremely powerful, but they can dramatically speed up how fast your auto repair project it taking.
A powerful impact wrench will even unlock repairs that you otherwise cannot do. For example, a car needs at least 1,000 foot-pounds of reverse torque to remove the crankshaft nut.
A 1-inch impact wrench is going to be required for that.
The good news is that you don’t need nearly as much power for lug nuts. Lug nuts only need to be tightened to about 120 foot-pounds of torque.
If they are rusty or have been over-tightened than you will need a more powerful wrench to remove them, however, in an ideal case, a larger impact driver with 1400 inch-pounds of torque (or more), should be able to remove most lug nuts easily.
And, you could always keep a breaker bar around for those super-stubborn nuts.
One of the biggest advantages of the impact driver is that you don’t need air supply to run it.
With pneumatic impact wrenches, you also have to buy a large air compressor and hoses for it.
They do make cordless impact wrenches; however, they are much larger and limited in what tasks they can do.
With an impact driver, you have a small, lightweight, cordless tool that can access just about any part of the car and make short work of any repair job.
A pneumatic impact wrench is still a good choice for those times when you need a larger amount of power in a small form factor. Right now, the cordless versions can match the power output of the pneumatic models, but they are much larger and more cumbersome.
For those day-to-day tasks that don’t need a lot of power, an impact driver is hard to beat.
Impact Driver Vs. Air Ratchet
The cordless impact driver is best compared to an air ratchet. While an air ratchet is smaller and better suited for reaching into those smaller areas of the engine bay, I do not know of a single shop that doesn’t also have an impact driver.
The ability to easily pop the bit in and go to work without worrying about air hoses makes the impact driver a favorite of home-hobbyists. It’s an excellent tool and one that you’ll be using daily.
If you are going to be doing a lot of tire changes, it is going to be worth your time to invest in an impact wrench. Even a 1/2-inch impact wrench will deliver more than enough power for tire changes.
However, for the occasional tire change in the home garage, an impact driver might be all that you need.
Eventually, you’ll want one of each. But, if the budget is tight, go for the impact driver, and convince your buddy to splurge on the impact wrench. Then you can just borrow his anytime you need it.