It depends on how much boost you are using and how much you keep the butterflies wide open. I run 13-14 psi and with the shim I have the meth starting at 8 psi and coming on full at 20-22 psi. I do not need full meth at the boost I am running. If I were just doing 1000 ft w/o runs that tank with the kit would last 1 tank to 1 1/2 tanks. I also have the failsafe kit, I was nervous about running out until I got a feel for the usage. I still am happy I got the failsafe, alot of money riding on my meth.