tmckenna

yeh unfortunately thats what I was thinking. Ive had older VWs and Audis and ran 0 AWG wire to the trunks of most of them. I just wish the cayenne had the battery in the trunk like my C6 A6 Avant did lol.

CAVU

A number of folks I know that leave the pavement, swear by and use https://powertank.com/

Eskimo1

This. When I was big into rock crawling, I ditched the on-board air idea in favor of a small (5lb) co2 tank and regulator setup. Cheap to fill, easy to transport, and supremely portable...

tmckenna

See, now you guys are why I asked this question lol. So the idea is that you use more compressed CO2 to fill the tires, instead of creating compressed air on the spot? Thats pretty interesting, just seems pretty expensive compared to most of the tanks I have experience with from paintball a couple years ago. I understand theres probably a lot of technology in the regulators, but the bottles themselves are usually dirt cheap.

tmckenna

What kind of regulator does the tank require. From my very limited research it seems this type of system can be pieced together for much MUCH less than $900 for a 20lb tank.

Eskimo1

The tank you can get from beverage distributors - it's common for guys with kegs. 5lb would be fine for the size of tire a Cayenne uses. 10lb if you want overkill. (I carried a 5lb for use with 42" tall x 14" wide tires if that tells you how much is in a 5lb cylinder!)

Powertank was always a pricy option... I used this - Hyperflo fixed regulator: https://wheelersoffroad.com/co2-regu...isconnect.html This has a regulator and tandle / valve guard in a kit, which is nice.. https://ebay.us/K5wXlY

Just make sure you use a high quality hose - the outlet of the co2 regulator will get COLD during use, and cheaper coiled hoses get brittle and crack.

tmckenna

Was looking at this:


And a 20lb tank. Im guessing youd say 20lb is way overkill but Im hoping I can make one tank last all summer. I'm running just about 31" all terrain tires on a 20" wheel. If you had to guess, how many reinflations (from about 12psi to 40psi) do you think a 5lb tank perform. Figure 4 wheels a trip and i might go once or twice a week in the summer, so a higher quantity might be something like 25 times in a summer, so 100 wheel fills. Realistically I probably wont go 25 times but that would be a comfortable over estimate.

CAVU

recommended reading: https://powertank.com/apps/help-cent...the-difference

Also, these are liquid CO2 systems which, via their "special regulators, convert it to high pressure high volume gas which is what you are looking for.

....and you will make new acquaintances at the beach while you are airing up in a matter of a couple of minutes.

tmckenna

Yeh exactly lol. People on my beach practically brawl over air sources. The problem is that people suck and steal the air hoses, so there are a total of only 2 or 3 spots that have beach provided hoses, but then 4 or 5 that just have empty female quick connects. The waiting lines arent usually bad if you bring your own air hose, but if you forget youre gunna wait at least a half an hour.

tmckenna

On a somewhat related note, does anybody here have any real experience with using co2 to fill tires. Ive done a bit of research today and Ive read a ton of hypothetical situations. Some that say co2 will leak/diffuse faster than air and some that say it wont.

There was even one post where the guy did the math and found the diffusion rates of co2, nitrogen, and atmospheric air through rubber and determined that co2 would diffuse 11 times faster than normal air. As convincing as this was, Powertanks explicitly says co2 WILL NOT leak/diffuse out of the tires faster than air.

With all this contradictory information everywhere Im just curious if anyone has real world experience and could comment on the rate at which the tires may "deflate" after using co2 to fill them.

Eskimo1

I've not seen it be a real-world problem from anyone I know. Can't use my race bike as an example because the tires don't stay on (or at the same pressure) long enough to matter. My rock buggy used beadlock wheels which always leaked a little, regardless of shop air or co2 being in them. :P

If you're going that often, yeah, get the bigger tank.

The regulators don't convert liquid co2 - the valve in the tank doesn't have a siphon tube, so it draws gaseous co2 off the top of the tank. Since I'm sure there are chemist-types who can explain the boiling point vs. pressure vs. state MUCH better than I, I'll just say that it's a lower pressure way of storing a whole bunch of gas in a small container.

tmckenna

Thank you for all the info! I read up on the whole liquid co2 idea. Doesnt really seem to be an issue if you hold the tank upright while filling the tires, and power tanks makes an anti siphon fitting for tanks that remain horizontal while filling.

tmckenna

Im assuming it should be find considering how widely it is used, but does anybody know if there is any risk to the Tire Pressure Sensors when using co2?

RAudi Driver

I run a few Co2 tanks in the studio trucks. They were originally used for blowing special effects out of certain types of guns. They are now mostly used for filling up tires of all types (gators, golf carts, dollies, bikes cars, etc...). Hand truck tires will go flat within a few days. Bikes and golf carts in a week or two. I'm changing them all out to Nitrogen tanks this spring. CO2 sucks for tires, PERIOD!

tmckenna

Hm, thats definitely discouraging lol