A cordless 21 mm polisher for large vehicles, for anyone already on the Milwaukee M18 platform.
Amazon $254.99The Milwaukee M18 FUEL 21mm is the better dual action car polisher overall, rated 3.6 to 3.5. The Milwaukee M18 FUEL 21mm leads on correction. The Milwaukee M18 FUEL 15mm wins on features.
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.
A cordless 15 mm polisher for anyone already on the Milwaukee M18 battery platform.
Amazon $254Which should you buy?
- Choose the Milwaukee M18 FUEL 21mm for correction (21 mm orbit vs 15 mm orbit).
- Choose the Milwaukee M18 FUEL 15mm for features (constant-speed electronics, cordless or a 20 ft+ cord, lock-on trigger vs cordless or a 20 ft+ cord).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every cordless dual action car polisher; a clear win is highlighted. How we rank explains each one.
| Factor weight | Milwaukee M18 FUEL 21mm | Milwaukee M18 FUEL 15mm |
|---|---|---|
| Overall rating | 3.6/5 | 3.5/5 |
| Correction 30% | 100 21 mm orbit | 62 15 mm orbit |
| Value 25% | 48 $254.99 | 48 $254 |
| Warranty 15% | 50 3-year warranty | 50 3-year warranty |
| Power 10% | 50 18 V battery; cordless makers publish no motor rating (neutral score used) | 50 18 V battery; cordless makers publish no motor rating (neutral score used) |
| Weight 10% | 50 weight not published (neutral score used) | 71 5.2 lb |
| Features 10% | 15 cordless or a 20 ft+ cord | 60 constant-speed electronics, cordless or a 20 ft+ cord, lock-on trigger |
Specifications
| Milwaukee M18 FUEL 21mm | Milwaukee M18 FUEL 15mm | |
|---|---|---|
| Polishing | ||
| Orbit diameter | 21 mm | 15 mm |
| Speed range | 2,400-4,500 OPM | 2,650-5,100 OPM |
| Backing plate | 6 in | 5 in |
| Forced rotation | No | No |
| Power | ||
| Power source | Cordless | Cordless |
| Battery | 18 V | 18 V |
| Cord | Cordless | Cordless |
| Brushless motor | Not listed | Not listed |
| Controls | ||
| Constant-speed electronics | Not listed | Yes |
| Soft start | Not listed | Not listed |
| Lock-on trigger | Not listed | Yes |
| Build | ||
| Weight | - | 5.2 lb |
| Pads or polish included | No | No |
| Warranty | 3 years | 3 years |
