Re: Has Anyone Done This With Pressurized Tank Home › Forum › Ask A Member › Has Anyone Done This With Pressurized Tank › Re: Has Anyone Done This With Pressurized Tank chris-pReplies: 2456Topics: 153 May 23, 2017 at 10:27 am #58186 More than you would think actually. You would be surprised how much is sent back, especially when idling. You have to run the tanks down dry almost, then re fill with fresh mix. Otherwise, the tank will eventually start to get over rich with oil.