Viair 400c verses 450c

I have a Jeep with 35″ tires, and an LR3 with 31.5″ tires. I have on board air in each vehicle, but slightly different set-ups. Today I tested them head to head to see what could be learned.

• Viair 400c hardmount, no tank. Direct hose connection
• Viair 450c hardmount, 2.0 gallon onboard tank, typically charged between 100-125psi for each test.

• Tire A: Cooper Zeon LTZ – 285/60/18
  31.6″ tire, 6.7″ sidewall, 11.2″ wide
• Tire B: ProComp Xterrian – 315/70/17
  34.4″ tire, 8.7″ sidewall, 12.4″ wide (35/12.5/17)

The Viair 400 fills Tire A as follows:

– 15psi to 42psi: 3:15 minutes (typical sand pressure)
– 25psi to 42psi: 2:30 minutes (typical off road pressure)

The Viair 450 fills Tire A as follows:
– 15psi to 42psi: NOT TESTED (typical sand pressure)
– 24psi to 42psi: 4:30 minutes (typical off road pressure) The Viair 400 fills Tire B as follows: (typical off road pressure)
– 12psi to 32psi: 3:28 min The Viair 450 fills Tire B as follows: (typical off road pressure)
– 12psi to 32psi: 3:45 minutes (First tire with charged air tank)
– 12psi to 32psi: 4:47 minutes (tires #2 – 4) Fun facts:
– For the Viair 450 to fill the 2 gallon tank from 0-125psi takes 1:45 minutes
– For the large 35″ tires to deflate from 32psi to 12psi using Stauns: 5:30 minutes (seems like forever!)
– For the smaller 31.5″ tires to deflate from 42psi to 25psi using Stauns: 2:20 minutes
– For the smaller 31.5″ tires to deflate from 42psi to 15psi using Stauns: 4:40 minutes
– The 400c is rated for about 30 minutes continuous use before it reaches critical temp and shuts off. I can easily fill all the tires on two trucks in that time.
– The 450c is rated for 120 minutes continuous use, and may possibly keep going at cooler air temps.

Summary:

– The 400 fills the smaller tires twice as fast as the 450, and about a minute faster on the larger tires than the 450.
– Having the air tank helps the pump run less and keep cooler, thus running longer.

I think a good combo is the 400c with a 2 or 2.5 gallon tank is a great set up to fill tires and run air tools if you are going to using it for time intervals under 30 minutes.