So with my Tracker having small frame rails, there's not much clearance under the floorboards to hide a tank.  The smallest I've seen is 6" dia. I think.
What's everyone else's onboard air tank/compressor setups?  Pictures would be helpful.
I'm also undecided whether or not I want to install a compressor and tank (self-generating supply) or a pressurized cylinder (needs refilling).  I only have 30" tires so I don't need lots of air but I don't want to refill a CO2 or nitrogen cylinder every trip.  How long do they last, in your opinions?
If anyone has any special sized tanks that are DOT approved, I'm especially interested.

A friend of mine runs a power tank (I think that's what it called). We both are running 37x12.50's and can go multiple trips airing up both vehicles from 6-8 PSI to 20-25 PSI without a refill. When I get air, that is what I'm going to run.

Zig

I know they work great.  I've heard of guys in the 35-37 range going 4 trips before worrying about refill.
Powertanks seem to be overrated.  I can get a cylinder at the local supply house for hardly anything compared to the price of the powertank.  Their advantage lies in the fact that they sell full "kits" and their tanks are lightweight aluminum.
Trying to go the "self-generating" route first if I can find a tank with the right dimensions.  I don't want to pressurize my bumpers, it seems like a good idea but I don't think I'd have much capacity

i run a factory a/c compresor into a 3 gallon tank mounted behind the rear seat. i can fill it to 100 psi in less than 30 seconds at idle. its the only way to go in m opinion.

If it didn't get so freakin hot and humid here in the summers I'd convert my ac to an air pump as well. LilRed's husband Duane has that setup and once filled my tires in about 30 seconds each!

Not sure if this would be too big for you, but WARN makes a 2.5 gallon "hot dog" tank.

7.3" wide, 8.5" high, 24.25" long.

http://www.warn.com/truck/air_accessories.shtml

- Andy

If it didn't get so freakin hot and humid here in the summers I'd convert my ac to an air pump as well. LilRed's husband Duane has that setup and once filled my tires in about 30 seconds each!

He finally got my Sidekick converted too just a a couple of weeks ago!  Tank, pressure valves, etc came from a used contractors portable compressor that he picked up at auction for $5! Please excuse the mess.  We've been wheeling!

under hood tank


inside switch & gauge, kicks on a 95#, kicks off at 125#


outlet on front bumper, gotta get a cover for it


Next . . . air horn!!!

Nice LilRed! Hey is that bumper and winch a new addition? Don't remember it.

Nice LilRed! Hey is that bumper and winch a new addition? Don't remember it.

Thanks!  I didn't have the winch/bumper last time we wheeled, but then that's been a while!  Had it about a year & a half.  Should have done it sooner!

Ya'll take care up there in this weather mess. 

Good tank location. I have factory air intake so it'd have to be a bit different. Wish I could do something like that tho

If you have a body lift of at least 2" theres a fair amount of space between the frame and body just forward of the upper rear coil mount, where the frame begins to drop down. I have a 4 or 5'" diameter tank running across the frame there for coolant. don't see why an air tank of similar dimensions couldn't be mounted there. Out of the way, weight low in the chassis.

That's another idea that I know I have some room there, even with no body lift.  It would be out of the way and protected from rocks.  I noticed that space some time ago but I don't think it would net me a very large tank.  Probably compress the suspension to see how much room I have

Since it sits above the frame the suspension has no effect on clearence. I know a 5" tank thats the width of the frame will hold over 2 gal of liquid.

hey, LilRed if you dont mind can you expand on the air setup you have?

Mine uses the factory a/c compressor.  Added an oiler & air filter off of the compressor



 and a line from the compressor to the tank.  The red line in the pics above runs from the tank to the pressure gauge & toggle off/on switch mounted in the cab with a pressure switch in that line that is set to kick the compressor on at 95lbs and off at 125lbs.  Click on the pic to make em bigger & take to all pics.