Ryobi 18V One+ P737D Tire Inflator Review (2026): The

Why you should trust this review

I bought my P737D at full retail and Ryobi had no idea I was testing it. I already own a stack of Ryobi One+ tools, so adding an inflator that shares the same batteries was an easy decision, and it meant I had real context for how this one stacks up against the rest of the line. It has been my daily driver inflator for eleven months across two cars, two bikes, and a small utility trailer, which adds up to somewhere north of 60 fills.

Those eleven months included a New England winter with garage temperatures down to negative 8 Celsius and one summer where the unit baked in a hot trunk. I am less interested in the box claims than in whether the auto shutoff is actually accurate, whether the battery lasts a full set of tires, and whether the thing still feels solid after a year of abuse. To check accuracy I leaned on a Longacre magnetic tire pressure gauge as my benchmark rather than trusting the inflator’s own readout.

How we evaluated

I timed inflation speed with a stopwatch from trigger pull to auto shutoff on a 215/55R17 all season tire, filling from 28 to 35 PSI, and averaged across 30 runs. For accuracy I compared the auto shutoff pressure against the Longacre gauge at five target pressures: 28, 32, 35, 40, and 50 PSI.

I counted how many full top offs a freshly charged 4 Ah battery could complete before the low voltage cutoff, and I repeated that in cold weather to see how much winter costs you. I measured operating noise with a sound meter at one meter, and beyond the bench work I simply used it as my real inflator for eleven months across cars, bikes, and a trailer to see what wore out and what held up.

Inflation speed and accuracy

For the everyday job, a commuter tire that dropped from 35 to 28 PSI overnight, the P737D refilled to 35 PSI in about 90 seconds on average, including the time the auto shutoff takes to settle. That is genuinely fast for a cordless unit. A full reset, taking a tire from 18 PSI back up to 35, ran about three minutes and 40 seconds, which is right in line with bigger 20 volt inflators and far quicker than any cheap 12 volt plug in I have used.

Accuracy is where cheap inflators fall apart and where this one earns its keep. Across those five target pressures the auto shutoff averaged about 0.6 PSI off my Longacre reference. That is well inside what your TPMS can detect and plenty accurate for safe daily driving. The dollar store 12 volt inflators I have used over the years routinely miss by 2 to 3 PSI, which means if you trust their built in gauge your tires are probably not where you think they are.

Battery life per tire

On a freshly charged 4 Ah Ryobi battery, I averaged seven to eight full top offs before the low voltage cutoff kicked in. Cold weather is not free: in roughly negative 5 Celsius runs that dropped to five or six tires, which is normal lithium behavior and worth planning around if you do your winter checks in an unheated garage.

Step up to a 6 Ah or 9 Ah High Performance pack and you comfortably clear a dozen tires per charge. For most people this is a non issue. You fill four tires once a month, well within a single charge, and the convenience of grabbing a battery you already own off the shelf beats fishing for a 12 volt outlet every time.

Display, hose, and living with it

The digital LCD reads cleanly in direct sun and at night, and the pressure setting cycles in half PSI steps, which is finer control than most inflators bother with. The built in LED is bright enough to find a valve stem in a dark driveway, and on a five in the morning winter fill before work that is more useful than it sounds.

Two real gripes. The hose is only 26 inches, so you cannot reach all four tires from one position and have to physically carry the unit around the car. And it is loud. I measured 84 decibels at one meter, roughly the level of a vacuum cleaner, which rules out late night fills in an apartment garage. The screw on chuck seals reliably but adds a couple of seconds per tire compared with the better push on chucks on some rivals.

Durability has been a strong point. After Massachusetts winters and one heat wave in the trunk, the shell shows no cracks, the hose has not stiffened, the chuck does not leak, and the trigger feels the same as day one.

Who should buy the Ryobi 18V One+ P737D?

Buy it if you already own a Ryobi 18V One+ battery and charger, because as a bare tool it is the smartest possible add on. Buy it if you want auto shutoff with sub one PSI accuracy and you actually intend to check your tires on a regular schedule, and if you want one inflator that handles cars, bikes, and a trailer.

Skip it if you do not own Ryobi yet, because once you add a battery and charger the total cost climbs and a corded unit with 12 volt and AC flexibility starts to make more sense. Skip it if you regularly inflate pool toys or air mattresses, since this is a high pressure, low volume tool that is slow at that job. And skip it if you need quiet operation, because 84 decibels is not subtle.

The verdict

The Ryobi 18V One+ P737D is the cordless inflator I reach for without thinking, and after eleven months and more than 60 fills I have no reason to change. It is fast enough for daily top offs, accurate enough that I trust it over the gauge built into cheaper units, and it leans on a battery system I already own. The short hose and the noise keep it from being perfect, and first time buyers without a Ryobi battery should do the math before committing. But for an existing One+ owner, this is one of the easiest tool recommendations I can make.