I've been reading these forums and learning a lot. I'm thinking of getting a backpack blower. Do all of them use a 50:1 mix? I have a 9 year old Ryobi string trimmer that uses 32:1 mix. Does everyone have 2 different mixes or do you buy units that only use the 50:1? Maybe all of the new trimmers and blowers use 50:1? How long would the Ryobi last if I started using 50:1 in it?