Milwaukee M18 FUEL 21mm
#1 in CordlessFull review
A cordless 21 mm polisher for large vehicles, for anyone already on the Milwaukee M18 platform.
Amazon $254.99$254.99
The Milwaukee M18 FUEL 21mm rates 3.6 among cordless dual action car polishers; the RUPES BigFoot LHR21 Mark V rates 3.4 among corded long-throw ones. The Milwaukee M18 FUEL 21mm costs $339.01 less ($254.99 vs $594).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
RUPES BigFoot LHR21 Mark V
A 21 mm polisher for big, flat panels on trucks, vans and boats, for professionals who already own a smaller machine for tight spots.
Amazon $594$594
Scores side by side
These two sit in different type classes (cordless and corded long-throw), and each is scored against the reference points for its own class, so a rating says how well each does among its own type peers. How we rank explains each factor.
| Factor weight | Milwaukee M18 FUEL 21mm | RUPES BigFoot LHR21 Mark V |
|---|---|---|
| Overall rating | 3.6/5 | 3.4/5 |
| Correction 30% | 100 21 mm orbit | 100 21 mm orbit |
| Value 25% | 48 $254.99 | 1 $594 |
| Warranty 15% | 50 3-year warranty | 100 5-year warranty |
| Power 10% | 50 18 V battery; cordless makers publish no motor rating (neutral score used) | 14 500 W |
| Weight 10% | 50 weight not published (neutral score used) | 66 5.4 lb |
| Features 10% | 15 cordless or a 20 ft+ cord | 15 cordless or a 20 ft+ cord |
Specifications
| Milwaukee M18 FUEL 21mm | RUPES BigFoot LHR21 Mark V | |
|---|---|---|
| Polishing | ||
| Orbit diameter | 21 mm | 21 mm |
| Speed range | 2,400-4,500 OPM | 3,000-4,500 OPM |
| Backing plate | 6 in | 6 in |
| Forced rotation | No | No |
| Power | ||
| Power source | Cordless | Corded |
| Motor rating | - | 500 W |
| Battery | 18 V | - |
| Cord | Cordless | 30 ft |
| Brushless motor | Not listed | Not listed |
| Controls | ||
| Constant-speed electronics | Not listed | Not listed |
| Soft start | Not listed | Not listed |
| Lock-on trigger | Not listed | Not listed |
| Build | ||
| Weight | - | 5.4 lb |
| Pads or polish included | No | No |
| Warranty | 3 years | 5 years |