| Design | | Acceptable Design - While this driver has one or more design features that received a C rating, it can still be a good choice if that area is not critical to your particular needs. |
| Power | | Below Average Power - Delivers up to 1150 in-lbs of torque, about 18% less than the class average. Power can sometimes be traded for weight or cost. |
| Speed | | Below Average Speed - Generates up to 2500 RPM, about 2% slower than the average impact driver. The Hitachi WH18DFL ranks in the bottom 45% of its class for speed. |
| Weight | √ | Light-Weight - Weighs only 3.3 lbs, about 9% lighter than the average impact driver. Ranks in the top 15% of its class for being light-weight. |
| Battery | | Below Average Run-Time - Battery endurance is adequate for many work applications, but is 32% less than the class average. Uses Li-ion batteries with a charge rating of 1.5 Ah. |
| Impact | | Below Average Impact Rate - Generates 3000 IPM of maximum impact blows, about 4% less than the average impact driver. |
| User Reviews | √ | Highly Satisfied Users - Rated 4.4 of 5 stars by 8 users. Most owners are very satisfied with the performance and value of this impact driver and would recommend it to others. |
| Power Ratio | | Below Average Power Ratio - Power-to-Weight ratio is 9% below average and ranks in the bottom 20% of its class. P/W is a good indicator of driver efficiency. |
| Gearbox | | Nylon Gears - Transmission includes at least some nylon gears that may need replacing after years of extended use. A nylon gearbox helps reduce driver weight. |
| Motor Brushes | | No External Access - The motor brushes can only be accessed internally by taking the driver apart. While not a common problem, external access makes the replacement job much easier. |
| Warranty | √ | Longer Warranty - Backed by Hitachi's limited 10-year warranty. This provides extra protection against potential design defects or premature part failure. |
| Charger | √ | Quick Charge - The Hitachi WH18DFL includes a battery charger that will recharge a battery in only 30 minutes. Long charge times are a common complaint with some drivers. |
| Belt Hook | √ | Belt Hook - Handy feature that allows you to temporarily hang the driver from your belt or a ladder while you're performing other tasks. |
| Work Light | √ | Work Light - Contains an integrated LED work light that illuminates your work area and allows you to clearly see your driving position and progress. |
| Fuel Gauge | | No Fuel Gauge - Does not come equipped with a handy battery charge indicator that allows you to glance at your driver and check the battery life while you're working. |
