All you need to know about car tuning stages

Vehicle part makers quote modifications in Stages usually but what does this mean? It is usual for performance part makers and tuning houses to use the numbers 1 – 3 to for each state of tune. To be frank it is actually quite  meaningless as they often mean different things but there are some common threads we can infer between them all.

What do each tuning stages refer to and how do they differ when comparing say a stage 1 with a stage 3 modification.

Everyone you ask will have thier own idea and no stage is tied to a power gain or percentage figure.