This page compiles the hands-on testing we have already published in the individual reviews. It adds no new measurements: every score, spec and figure below comes from the linked review.

AstroAI

AstroAI 12V DC Portable Air Compressor

4.4 out of 5

The easiest inflator to recommend for everyday drivers: set the pressure, press start and walk away. It is slower and less rugged than a VIAIR, but the convenience per dollar is unmatched.

Ryobi

Ryobi P737D 18V ONE+ Cordless Inflator

4.5 out of 5

If you already own Ryobi ONE+ batteries, this is the most convenient inflator you can buy: digital preset, no cables, and enough runtime for a full set of tires on one 4.0Ah pack.

Sub-scores from our reviews

The five dimensions behind every overall score on this site, taken verbatim from each review. A dash means the review does not publish that sub-score.

Sub-scores for AstroAI 12V DC Portable Air Compressor and Ryobi P737D 18V ONE+ Cordless Inflator
DimensionAstroAI 12V DC Portable Air CompressorRyobi P737D 18V ONE+ Cordless Inflator
Inflation speed3.64.0
Gauge accuracy4.74.8
Build quality4.04.5
Portability4.84.9
Value4.94.5
Overall score4.44.5
Typical price$39.99$49.00 (bare tool)

Specifications both publish

Published specifications for AstroAI 12V DC Portable Air Compressor and Ryobi P737D 18V ONE+ Cordless Inflator
SpecAstroAI 12V DC Portable Air CompressorRyobi P737D 18V ONE+ Cordless Inflator
Maximum pressure150 PSI150 PSI
Air flow1.2 CFM at 0 PSI0.57 CFM at 0 PSI
Power source12V DC cigarette plug, 10 ft cordRyobi 18V ONE+ battery (bare tool, no battery included)
Hose length2 ft braided hose with 1 ft extension20 in high-pressure hose
Duty cycle10 minutes on, 10 minutes offContinuous use, thermally protected
Weight2.1 lb (0.95 kg)3.6 lb (1.63 kg) with a 4.0Ah battery
Included adaptersPresta adapter, ball needle, nozzle adapter, zippered bagPresta adapter, sports needle, high-flow nozzle

What you accept with each

AstroAI 12V DC Portable Air Compressor

  • About 70% slower than the VIAIR 88P on the same tire
  • Plastic housing and a short hose that stiffens in freezing weather
  • 10-minute duty cycle means one tire, then a cooldown
  • 12V plug can blow a 15A accessory fuse on some older cars

Ryobi P737D 18V ONE+ Cordless Inflator

  • Sold as a bare tool — battery and charger cost extra if you are not already in the ONE+ system
  • Slower than a battery-clamp 12V compressor on a completely flat tire
  • Bulkier than a 12V inflator and heavier in the hand at 3.6 lb with a 4.0Ah pack
  • The 1/4 in hose has no standard quick-release, so aftermarket accessories need an adapter

Which one, for whom

Choose the AstroAI 12V DC Portable Air Compressor if you weight value more heavily, and the lower price ($39.99 against $49.00 (bare tool)) matters.

Choose the Ryobi P737D 18V ONE+ Cordless Inflator if you weight inflation speed, gauge accuracy, build quality, portability more heavily.

Neither is a bad unit — both cleared the same protocol. Read the two full reviews before deciding: AstroAI 12V DC Portable Air Compressor review and Ryobi P737D 18V ONE+ Cordless Inflator review.