The short answer
Choose around where and how often you fill tires.
A cordless inflator is convenient for a truck, driveway, or roadside top-off when you want a self-contained tool. A suitable air compressor is more practical when you regularly inflate multiple tires or also use air tools. The right answer depends on your setup; our test was of one cordless inflator, not a head-to-head comparison.
What we measured
Milwaukee M18 on one full-size truck tire
In our timed test, the Milwaukee M18 Tire Inflator took a full-size truck tire from 0 to the 42 PSI setting in 5 minutes 55 seconds using an M18 XC6.0Ah battery.
In a separate accuracy check, a tire starting at 34.5 PSI was filled with the tool set to 42 PSI. A separate gauge read 41 PSI afterward, about a 1 PSI difference from the setting. That check was not the ending gauge reading for the timed fill.
Watch the timed truck-tire fill
The video shows the 0-to-42 PSI fill in 5:55 and the separate pressure check. It is one cordless inflator, not a compressor comparison.
When a cordless inflator makes sense
If you mainly maintain tire pressure or want a portable way to fill a tire away from an outlet, a cordless inflator avoids carrying a compressor and hose. An existing battery system can make it especially easy to keep the tool ready. Our M18 test shows that this particular setup completed one demanding fill; it does not establish how many truck tires one charge will handle.
Keep a charged battery available, give the tool the ventilation and duty cycle its manual calls for, and check the final pressure independently.
When an air compressor makes sense
If you repeatedly air down and refill tires, service several vehicles, or already need compressed air for other work, a compressor with an appropriate air supply may fit your routine better. Compare the actual compressor, hose, fittings, electrical supply, and maintenance you would use. Compressor sizes and output vary widely, so a generic claim that every compressor is faster would be misleading.
We did not time a compressor against the M18 in this test. Treat the measured 5:55 as a reference for one cordless setup, not a speed ranking.
What to check before buying
- Your use: routine top-offs, an occasional full fill, or repeated fills after airing down?
- Power: charged batteries where you need them, or a suitable outlet and compressor?
- Reach and fittings: can the hose comfortably reach every valve on your vehicle?
- Pressure verification: keep a separate, trusted gauge and follow the vehicle’s recommended cold tire pressure.
- Practical limits: look at the maker’s operating instructions for heat, rest periods, and battery or power requirements.
How to use the 5:55 result
Use it as a concrete example of what one Milwaukee M18 with an XC6.0Ah battery did on one full-size truck tire, from 0 to the 42 PSI setting. It does not predict your exact time on a different tire or starting pressure. The separate 41 PSI gauge reading from a 34.5 PSI start is useful context, but one gauge check does not prove accuracy across all pressures.
Milwaukee M18 Tire Inflator truck-tire review
See the visible timer, full test setup, and the separate pressure check.
Read the review and watch the videoMore Fennell Tested