CO2 Tank – Tips

Anyone who said 4-wheelers aren’t passionate about their sport doesn’t know what he’s talking about. Wow. Within hours of sending my message on Thursday, Oct. 25, my inbox was loaded with replies.

All of you provided some very valuable information on the vendors you use to fill tanks, which will be on my Web site soon – watch for that. In the meantime, I’d like to share some comments that arrived.

This is a compilation of feedback and tips received from CO2 Tanks users. There is some repetition of some ideas but it paints a strong picture.

Co2 Tank Use -Tips

  • CO2 is popular because more cubic volume can be compressed in the tank. The downside is condensation inside the rims and freezing of the regulator under heavy use.
  • Nitrogen does not provide as much cubic volume and hence you must carry a larger tank. Upside is that there is no condensation; the gas is not subject to as much change under heat so pressures stay relatively the same when the tire is cold or hot. Regulator does not freeze up under heavy usage.

Filling Up

  • I call before hand to find out when they are filling CO2. If I schedule my time to match theirs, they fill while I wait, if not it stays overnight
  • They have always been very careful with my tank (when filling it). They use adjustable wrenches. Bring your own if you are worried about marking.
  • You cannot reliably fill CO2 unless the tank is empty. They do properly fill the tank though, this is key. That is they start with an empty tank, put it on the scale to get its tare weight, and then fill it up with 10lbs of CO2 by weight.
  • Knowing the weight of your tank empty and full is vital. So is knowing how many tires it can fill per pound or half
  • I weighed the tank to determine how much CO2 was left but I had trouble visualizing the result. I used a permanent marker to mark a scale on the side of the tank showing Full, 3/4 Full, 1/2 Full, 1/4 Full, and Empty. Alongside each of the five marks I wrote the tank’s weight at that capacity. Now when I weigh the tank, I just look at the scale and it’s easy to visualize how much is left. Calculation: You measure the Full weight and Empty weight. Subtract the Empty weight from the Full weight and divide the result by four to get the “number”. Add this number to the Empty weight to get the 1/4-Full weight. Then add this number to the 1/4-Full weight to get the 1/2-Full weight. Finally, add this number to the 1/2-Full weight to get the 3/4-Full weight. If you did your math correctly, you should be able to add this number to the 3/4-Full weight and get the Full weight.


  • It’s heavy, even empty, so it needs to be properly secured. You cannot operate it in the horizontal configuration, so if you want to use it without removing it from the vehicle you need to mount it (carrying bracket) in a vertical orientation.
  • Have a damn solid bracket or strap¦otherwise you have a potentially explosive missile in the back of your rig.
  • Get a bracket for the tank, they are available anywhere and not only make transportation of the tank a good deal safer they also make it a lot more convenient.
  • Their cylinders are made of aluminum, which eliminates my corrosion and cracking concerns.
  • I did a lot of research on the safety of having a tank in an auto; the worst that can happen is getting hit by the tank. If the top were to ever break there isn’t enough pressure there to turn it into a missile like some people think (only has about 600-700 PSI).
  • Always transport with the regulator removed.


  • Don’t skimp on the coil up hose, a cheap hose can get brittle and break under prolonged use such as performing repairs with an impact gun.
  • Don’t run on the trail w/ the cheap $20 air hose kit from Pep Boys hooked up to the tank. It bleeds too much.
  • Make sure you get a hose that is rated for 600-700 PSI. Stay away from the yellow nylon hoses they become brittle and will break
  • It’s good to have nice heavy duty air line for the line from the tank to the air chuck. I have had two of those cheap yellow plastic self-coiling air lines (purchased at Wal-mart and Kragen) rupture when leaving the tank in the hot sun with the valve open. I use higher quality hose now, but still immediately shut the valve off as soon as I am done actively filling tires. This takes pressure off the hose.
  • CO2 is cold and will freeze the line and fittings, so use good hardware.
  • Gauges are nice but I have never felt it important to know tank pressure because it’s my understanding that tank pressure is not an indication of fill level–the tank provides max pressure right up to the end.
  • Some people get the regulator with a gauge on it. I decided not to for reasons: the tank is under constant pressure, its liquid co2 but it holds vapor inside which keeps the tank pressurized “ thus the gauge will read full, until it is empty. You can check it by weight “ weigh the tank when it’s empty and then when it’s full “ when close to the empty weight go fill it.

In Use

  • Set the regulator for about 90psi, this will help control icing and is perfectly adequate for filling tires quickly, you can always crank the regulator up higher if you need to get particularly stubborn bolts off with impact (and I have).
  • Also when using impact you will notice the tool dying out after a short period of use, this is normal, just release the trigger and let the CO2 “spool up” again. Quick bursts are your friend here.
  • Power Tanks can only be used when they are in an upright position. The bracket holds the Power Tank upright and accessible so I can fill my tires without having to remove the Power Tank from my car.
  • I can usually do 3 tires before my line freezes and I have to wait a bit to let it thaw, that’s when I reconnect my anti-sway bar, then finish the last tire, not a big deal. Because it is cold air, you will need to top off your tires the next day, mine usually goes down about 5-7psi overnight,
  • During cold conditions it works slower.
  • Several of my trail buddies even use it to frost their beer mugs at the end of the day in camp, just like the bars and restaurants do.


  • I have a portable air compressor (Pepboys $50) and it works great as a back-up. Liked using my large tank so much I found I wanted a second smaller tank; it’s great for taking on road trips in the car or when I go out wheeling/motorcycle riding/mtb riding/etc¦with friends without their own tanks. I keep the small bottle just in case I use up my large bottle out on the trail using tools or seating tires¦
  • Keep it inside the vehicle, use it wisely, and don’t share it, nice guys finish with three wheels full and happy friends. CO2 is not free air like compressed like an expensive Kilby or York.)

I’m still compiling the information, but one thing is strikingly clear: You prefer to use air compressors. (In fact, only about 30% said they used air tanks. However of the tank user, they overwhelmingly prefer CO2 instead of nitrogen.) A common sentiment for non tank users was expressed by this comment I received. I chose not to go with a CO2 version because when you run out, you’re out. Also, they have a limit to the number of tires they can fill up on one tank. When I’m out on the trail, I want to know that there will always be plenty of air for myself, my buddies and anyone else on the trail that may need my help. Having to ration my CO2 just doesn’t make sense to me. Thanks, again, to everyone for responding to my survey. Regardless of whether you use tanks or compressors, your feedback will help make our sport more enjoyable for all. I’ll see you on the trails!

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