Best Portable Air Compressor

The best portable air compressor is a dedicated tire inflator unless you also need to jump-start your car. For tires alone, get the NOCO AIR10 if your car has a 12V socket, or the Milwaukee M18 inflator if you already own M18 batteries and want no cord. If a dead battery is also a problem, get the WOLFBOX MegaVolt16 Air, a jump starter with an air compressor built in. If your tires are taller than 35 inches, or you air back up after trail runs, get the Viair 400P-A instead.

Best 4 In-1 Jump Starter with Air Compressor

The best 4 in 1 jump starter with air compressor is the WOLFBOX MegaVolt16 Air, and it's the best portable jump starter with air compressor for most drivers. One box holds a jump starter, a 160 PSI compressor, a 400 lm flashlight and a USB-C power bank. It's rated for 8 L gas and 6 L diesel engines, and it added 5 PSI to the 275/70R18 tires on an F-150 in about 3 minutes.

If you want a long air hose, get the NOCO Boost Air instead. It's a lithium-ion pack rated at 2,000 A with a long air hose.

Match what you see in your driveway or garage to one line:

• Your battery dies on you, your engine is 8 L gas or 6 L diesel or smaller, and you want tires and phone charging in the same box: the WOLFBOX MegaVolt16 Air.
• Same job, and you want a long air hose: the NOCO Boost Air.
• Your engine is a diesel bigger than 6 L or a gas engine bigger than 8 L, and you're covering tires with a separate inflator: GearLab's top pick for big engines, the 4,250 A NOCO Boost X.
• You only top off tires, your car has a 12V socket, and your tires are ordinary passenger size: the NOCO AIR10.
• Your pickup or SUV rides on tires up to 35 inches tall, or your socket can't carry an inflator, and you'll clamp to the battery: the NOCO AIR20.
• You only need tires and there's an M18 battery in the garage: the Milwaukee M18 inflator.
• Your tires are taller than 35 inches, or you air back up after trail runs: the Viair 400P-A.
• You air up several big tires back to back and want more airflow than the Viair: the ARB twin portable compressor.
• You run the compressor for an hour at a stretch on truck or RV tires: the Viair RV portable compressor.
• You refill completely flat tires often: the California Air Tools 8-gallon compressor.

Engine size moves most readers between the first three lines, and makers don't share one scale. Lectron's own guideline, as quoted by CR, runs from 800 to 1,200 peak amps for engines of 2.0 L and under, to 1,200 to 2,000 from 2.0 to 3.0 L, to 2,000 to 3,000 above 3.0 L, with diesels at 3,000 or more. Other makers, NOCO among them, rate engine size on a different basis. Match your engine to the size each pack is rated for, and if you're between two sizes, take the bigger one.

Socket limits move readers between the tire lines. Plug-in inflators draw from your car's 12V socket, and each vehicle sets its own limit. Mazda caps accessories on the MX-5 at 120 W (12V, 10 A), and the AIR10's motor is rated 138 W, so read your owner's manual for your car's number before you plug one in. If the limit is low, take the Milwaukee or the AIR20, which clamps to the battery. On any plug-in unit, keep sessions short and never fit a bigger fuse.

Skip three packs that keep coming up. The Stanley J5C09 (1,000 A) is sealed lead-acid, the lowest-rated of the 13 packs GearLab ranked, and it delivered less current under load than its rivals. The DeWalt jump starter with compressor is sealed lead-acid too, and it must be recharged after use. The GOOLOO GP2000 carries an 8 L gasoline rating in GearLab's report, but it lacked the power for larger engines.

Best Air Compressor for Car Tires

The best air compressor for car tires is the NOCO AIR10 if your car has a 12V socket. It takes tires up to 31 inches, fills from 0 to 40 PSI in 3.8 minutes, tops off from 35 to 40 PSI in under 41 seconds, and its preset-pressure shut-off stops it at the number you set. For taller tires or a limited socket, the NOCO AIR20 takes tires up to 35 inches, runs 0 to 40 PSI in 2.5 minutes and clamps to the battery on a 20 ft cord.

The best portable tire inflator without a cord is the Milwaukee M18 inflator, if you already own M18 batteries. It reached 30 psi in just over a minute and 45 psi in about two and a half minutes from 10 psi, the fastest handheld in the test. It tops out at 150 PSI, stops at a preselected pressure, and comes without a battery.

Cold changes the choice. Cordless units can lose performance below 20°F, so in winter take a 12V unit.

Completely flat tires change it again. Continuous operation can overheat handheld units on a flat, so if you refill flats often, get a tank compressor. The California Air Tools 8-gallon compressor holds 8.0 gallons and reaches 120 PSI.

Whichever you buy, inflate to the cold pressure on your car's tire label. It sits on the driver's doorjamb, and it lists the proper cold tire pressure for front, rear, and spare. Mazda puts the label on the driver's side B-pillar or the edge of the driver's door frame. The number molded into the sidewall is the tire's maximum, not your target. Set the shut-off to the label figure.

Check the result with a separate tire gauge, because built-in gauges miss. Some inflators were off by as much as 5 PSI.

Skip the Hilka 12V. It was the slowest in its test at 3:06 to reach an indicated 30 PSI, and its gauge read 22.5 PSI when the pump claimed 30.

Best Portable Car Jump Starter with Air Compressor

The best portable car jump starter with air compressor is the NOCO Boost Air, a lithium-ion pack with a long air hose. Its compressor reaches 100 PSI and runs 0 to 40 PSI in roughly 2 minutes. A pressure sensor stops inflation at the set pressure, the clamps are spark-proof with reverse polarity protection, and a 60 W USB port comes with it.

If you'd rather have the compact 4-in-1 pack from the first section, get the WOLFBOX MegaVolt16 Air.

A jump starter is judged on the current it delivers, and the headline number is peak amps: the maximum power the pack will output over a burst of a few seconds. That says little about a pack that has to keep cranking. Treat peak amps as the second check after rated engine size.

CR's buying guidance says CCA of 400 to 500 should suffice for passenger cars, SUVs and pickups, and it notes CCA is often missing from jump starter specs. Treat that as CR's guidance, not a pack spec. CCA is a battery test, defined under SAE J537 at -18°C for 30 seconds, and Power-Sonic says no lithium CCA standard exists, so each maker sets its own method. Shop on rated engine size and skip the CCA hunt.

Recharge on a schedule. Clore advises recharging about every 3 months for infrequent use, and monthly in extreme cold with the unit left in a vehicle. Lithium is always better served by frequent charging than infrequent charging.

Connect the pack the way its maker and your vehicle's manual say, because they differ. A Kia hybrid's manual uses a charging terminal in the engine-compartment fuse panel, while NOCO's GB40 guide sends the black clamp to the negative terminal or the chassis. Follow your vehicle's manual and the pack's.

Best Portable Air Compressor for 4x4

The best portable air compressor for 4x4 is the Viair 400P-A. It's rated for tires up to 37 inches, tops out at 150 PSI, and comes with a 30 ft coil hose, an inflation gun with a 160 PSI gauge and a dual-compartment carry bag.

One timed run of a VIAIR portable compressor took 3 minutes 23 seconds to bring a 35-inch tire from 10 to 35 PSI, powered by clips on the car battery.

If you air up several tires back to back, the best 12 volt air compressor for off-road is the ARB twin portable compressor. It has two motors and a 4 litre tank in a waterproof hard case, and ARB lists a 100% duty cycle at 22°C. Its airflow drops under pressure, and ARB's nominal factory figures show how much.

Plan on the lower number for real tires. ARB lists 50 A at 29 PSI, so check your vehicle manual for the socket limit before you plug it in.

For truck or RV tires, or runs of an hour, the Viair RV portable compressor is rated 100% duty at 100 PSI, described as up to 1 hour at a time. It has a 150 PSI maximum, 1.80 CFM at 0 PSI and a maximum tire size of 275/80R22.5.

A portable compressor stops where a system wired into the vehicle begins.

Best Compact Jump Starter with Air Compressor

The best compact jump starter with air compressor is the WOLFBOX MegaVolt16 Air. At 5.3 lb it weighs less than the NOCO Boost Air at 6.9 lb. If trunk space is tight, weight is the number to read first.

The heavy combos fail that test. The Stanley and the DeWalt both weigh 17.5 lb, and the Clore combo weighs 28.5 lb.

The AstroAI S8 Air is lighter still at 2.4 lb, but skip it: its hose is often too short to rest the unit on the ground.