I've had a JetCat P120, and now a Jetcat P160 in my BoomerangXL.

I used a 3litre tank with the 120 and I got 10 minutes safely taxi to taxi, with a 'safe' reserve.

I've now gone to a 4litre for the 160 and I get about the same 10 minutes safely taxi to taxi, with a 'safe' reserve.

Hmmm I must remember to springload my throttle stick!

By the way, there's not a great deal of difference speed wise between the 120 & 160 (my XL did 314km/h in a speedrun a couple of weeks ago) but the 160 gets you there quicker, and is great for verticals. That being said, I've heard successful stories using an 18lb Wren Supersport!

Cheers from New Zealand.