I returned a few days ago from a nice ride to the California coast and back. It was a great trip. While on the road one of my riding buds had a breakdown (he was on a metric, by the way) and fortunately I had some extra tools in my saddle bag. I busted one of my wrenches, though, so we went to a local Sears outside San Francisco to get it replaced.

While in the tool department I overheard a conversation between a guy and what I assume was his wife. They were looking at new air compressors. He was apprarantly trying to decide between two of the standup models, and it looked like the 20gallon and 33 gallon units. "If I buy the bigger unit it will weigh a lot more, and that means it is heavier. So it will harder to lift in and out of the truck."

"Why don't you just take the air out before you load it?" The wife asked.

He chuckled, then he realized she was serious. "What?"

"Take the air out, it will be lighter." She said.

He tried to sneak out without anyone seeing him.

We laughed about that for the rest of the trip.

 

Sounds like something my wife would say.

 

Hate to break it to you guys, but it will weigh less with the air out of it, not sure how much, but for instance an 80 cu ft scuba tank with air will weigh about 6 1/2 lbs more with air in it. It couldn't be much difference in the compressor tank since it is not compressed that much, but there will be a difference. There is some formula to calculate it but I am not sure what it is.