I have an Altronics setup. I used it all last year and so far have not had to replace anything. It is absolutely great for setting up the fuel. One thing you have to remember is it will only tell you what conditions you had during the LAST run. You would have to record all info at all conditions to be able to guess what changes to make if you you see a DA change. That said it is absolutely the best tuning aid I have ever seen. You can actually change ONE jet size and see the difference. If you want 13.5 you can put it dead on