VIAIR 400P Portable Compressor (40043) Review
A 150 PSI, 2.3 CFM compressor that clamps to the vehicle battery, built for truck and off-road tires up to 35 inches.
By Watt Versus Editorial· Updated
This page was drafted with AI assistance from manufacturers' specs and manuals, and is checked by our editor.
Our verdict
The inflator for big truck and off-road tires: it moves far more air than the cordless tools here. For quick top-offs on a car, a cordless unit is less hassle.
Pros and cons
Pros
- 2.3 CFM of airflow, against 1.97 CFM for the 88P; the cordless tools publish no airflow figure
- Rated for tires up to 35 inches: the pick for lifted trucks and airing back up after off-road trips
- 25 ft hose reaches all four tires and a trailer from one spot
- 5-in-1 hose head lets you let air out and check pressure as well
Cons
- 10.4 lb and clamps to the battery, so it is not a quick glovebox top-off tool
- No auto shut-off: you watch the gauge and stop it yourself
- Only a 1-year warranty
Specifications
| Max pressure | 150 PSI |
|---|---|
| Power source | 12 V vehicle battery, via dual battery clamps |
| Battery | Not needed (runs from the vehicle battery) |
| Airflow | 2.30 CFM at 0 PSI |
| Duty cycle | 33% at 100 PSI |
| Max tire size | Up to 35 in |
| Display | Inline 100 PSI gauge on the hose |
| Hose length | 25 ft coil hose with 5-in-1 inflator/deflator |
| Power cord | 8 ft; 30 A max draw |
| Included accessories | Carry bag, 3-piece inflation tips kit, Presta valve adaptor, sand tray, inline fuse holder |
| Weight | 10.4 lb |
| Warranty | 1 year |
The full review
Who it suits
Owners of trucks, SUVs and Jeeps on tires up to 35 inches, and anyone who airs down for sand or trails and needs to air back up four tires before driving home.
Who should skip it
Drivers of ordinary cars who only top off a few PSI now and then: a cordless or 12 V plug-in inflator is quicker to grab and needs no hood opening.
What we could not confirm
VIAIR's product page does not mention an auto shut-off, so we treat it as having none. VIAIR's warranty page gives one year for its products without naming models.
Frequently asked questions
- What size tires can the VIAIR 400P fill?
- VIAIR rates it for tires up to 35 inches.
- How does the VIAIR 400P get power?
- It clamps directly to a 12 V vehicle battery and can draw up to 30 A, which is why it does not use the cigarette-lighter socket.
- Does the VIAIR 400P shut off automatically?
- VIAIR does not list an auto shut-off for the 400P (40043). VIAIR sells a separate 400P-Automatic model for that.
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VS comparison
VIAIR 88P Portable Compressor (00088) vs VIAIR 400P Portable Compressor (40043)
Both clamp to the vehicle battery. The 400P moves more air, reaches higher pressure and handles 35-inch tires; the 88P is less than half the weight.
Updated October 15, 2026
Best of
Best Tire Inflators: Cordless, 12V and Off-Road
Nine inflators in four types, from a 2.2 lb plug-in for the trunk to a 150 PSI compressor for 35-inch truck tires.
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How-to guide
How to Choose a Tire Inflator (and How Much PSI You Need)
PSI ratings matter less than you think. Here is what to look at instead: power source, airflow, duty cycle and auto shut-off.
Updated October 15, 2026