Verdict
Head-to-head · Best Portable Tire Inflators

Milwaukee M18 Inflator (2848-20) vs Slime Cordless Pro Power

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

The short answer

Milwaukee M18 Inflator (2848-20) comes out ahead by a narrow margin (4.7 vs 4.5). The gap is mostly about Milwaukee M18 tool owners and pros who want the fastest, most accurate cordless tire top-off — read the strengths below before deciding.

Milwaukee M18 Inflator (2848-20)
Higher ratedRanked #1 in Best Portable Tire Inflators
Milwaukee M18 Inflator (2848-20)
$168.9as of Jun 7

The M18 2848-20 is the best cordless inflator if you already live in Milwaukee's battery ecosystem or want the fastest, most accurate cordless top-off available. Pro Tool Reviews and Tool Box Buzz both rate it near the top of the category. The catch is total cost once you add a battery and charger, and the lack of a 12V backup.

Strengths
  • Fastest cordless inflator tested, topping off an F-150 tire in about 52 seconds
  • Highly accurate digital gauge with auto shut-off, within ~2 PSI of a manual gauge
  • Runs noticeably quieter and lower-pitched than rival cordless inflators
Watch-outs
  • Tool-only price plus an M18 battery and charger makes it the most expensive pick
  • Heavy at around 9 lb with a battery attached
  • No 12V backup if the battery dies, unlike hybrid Slime/AVID units
Slime Cordless Pro Power
Ranked #3 in Best Portable Tire Inflators
Slime Cordless Pro Power
$115as of May 28

The Slime Cordless Pro Power is the best self-contained pick: it runs cordless on its own battery, falls back to a 12V cable if it dies, and auto-stops at your target pressure. Pro Tool Reviews scored it 9.4/10 and Automoblog 85/100. It is slower and lower-pressure than the Milwaukee and Viair, but the hybrid power and auto shut-off make it the most foolproof for most drivers.

Strengths
  • Hybrid design works cordless on its internal battery or wired via the included 12V cable
  • Inflate-Right Technology auto-shuts off at the set pressure, no gauge-watching needed
  • Fills up to three standard car tires from flat per charge
Watch-outs
  • Roughly four-hour USB-C recharge is slow
  • Fills more slowly than the Milwaukee M18 or Viair 88P at about three minutes per tire
  • 99 PSI ceiling is lower than the 120-150 PSI rivals

How they stack up

Milwaukee M18 Inflator (2848-20)

The fastest and most accurate cordless pick here, ahead of the hybrid Slime Cordless Pro Power and the budget AVID Power on speed and precision. Unlike the corded Viair 88P it needs no 12V outlet, but it also lacks their 12V fallback and costs the most once a battery is added.

Slime Cordless Pro Power

The most self-contained option, the only one here that runs cordless and still has a 12V fallback if the battery dies. It is slower and lower-pressure than the Milwaukee M18 Inflator (2848-20) and the Viair 88P, but more foolproof than older corded inflators and a step up in features from the budget AVID Power.

Specs side-by-side

SpecMilwaukee M18 Inflator (2848-20)Slime Cordless Pro Power
Max PSI15099
Power SourceM18 RedLithium batteryInternal battery + 12V cable
Auto Shut-OffYes, digital presetInflate-Right Technology
AccuracyWithin ~2 PSI
Fill Time~52 sec (6 PSI top-up, F-150)~3 min per tire
Weight~9 lb with battery
ChuckBrass Schrader
LightIntegrated LED
ChargingUSB-C, ~4 hr
Tires Per ChargeUp to 3
Charge Retention~4 months
DisplayClear-view LED
← See the full ranking of best portable tire inflators