How much fuel is enough on a Profile Carrier plane using a 35/36 size R/C engine? Plastic or metal?

     I build my tanks for Profile carrier to hold 5 oz and I have never run out of fuel. Course I have never gotten that record breaking flight that I have been trying for for the last 10 years. So not having ever gotten the record beaker I usually land with 1oz to 2oz left over. If you are looking to only hauling around the minimum fuel to get you through a normal to good flight 4oz is probably enough.
     When I'm out practicing a 6oz tank would be nice because it is nice to be able to fly one high speed section along with at least two 7 lap sections of low speed. The plastic tanks available today seem to come in either 4oz or 6oz, they seemed to have skipped over the 5oz tanks for some reason.
     I cant stress enough that practice, practice, practice is the key to success in carrier flying. I use a stodge to launch and then fly against myself and it can be quite enjoyable. It is not as much fun when you have brought someone along and that person is getting bored half way through you first session. The low speed section of the flight is pretty boring for a non carrier bystander but should be challenging and fun for the aspiring carrier flier.  eric