When designing our driving speed tests, we first searched online and across social media platforms to find providers rigorously testing impact driver speed in a standardized way across manufacturers. We found there needed to be more reliable resources.
Manufacturer marketing pages are full of hype and include little detail around claims such as “35% better driving speed” than the competition. Third-party testing online and across social platforms is, at best, limited and not held to high enough standards to provide reliable comparisons across tools.
This research explains why we set out to fill a needed gap with our more rigorous lab tests. We designed our driving speed tests to determine which impact drivers shine most in practical heavy-duty tasks, including driving lag bolts and long screws.
Below, we discuss in detail how we test driving speed and why it matters. Check out our impact driver driving speed test results to compare performance for all models in our test fleet.
What we test
We test how quickly each impact driver in our test fleet drives GRK RSS structural screws into pre-treated lumber.
How we test it
Each impact driver is set to its fastest drive mode setting with a fully-charged 2Ah battery used to standardize performance across brands. When a 2Ah battery isn’t available in a specific battery platform, we test the next highest Ah-capacity battery. For example, we test Makita’s 40V XGT models with a 2.5Ah battery.
Impact drivers are then run for 10 to 20 seconds to warm up the motor and other internals.
Five 5/16-inch, 5 1/8-inch long GRK RSS structural screws are set into 6×6 pre-treated lumber.
Each GRK screw is driven in the forward setting with the trigger instantly and fully depressed, followed by each screw being removed sequentially. The driving and removal time for each screw is recorded and rounded to the nearest tenth of a second. For example, a result of 4.34 seconds is rounded to 4.3 seconds.
In each review, we then display the total and average drive time in forward and reverse, totaling four data points. A video recording is also included in each review to simplify comparing performance across models in our test fleet.
Why it matters
The combination of an impact driver’s motor type (brushed vs. brushless), torque output, RPM, and impacts per minute determines how quickly an impact driver drives big screws and lag bolts.
For a select group of people, driving speed is one of the most vital factors to consider when buying a new impact driver. An impact driver that drives screws quickly can save time, which is especially important for repetitive and extended driving tasks where a few seconds in additional driving time for each screw adds up.
But consider that driving speed is most relevant for big screws, lag bolts, and other fasteners. Driving speed isn’t critical for 3-inch and shorter screws since nearly all impact drivers finish these tasks with similar speed, and not much is gained by being a fraction of a second faster. Plus, the shorter the screw, the more likely precision is needed, which is inversely related to speed.
The fastest models are mainly designed for professionals on job sites where they’ll commonly encounter heavy-duty driving tasks. This select group consistently pushes impact drivers to their limits, so they need the best impact drivers to save time and money.
