..when they are referring to various car parts? I have been googling and only been able to find that it has something to do with tuning? I'm currently driving an '11 G37x coupe and looking to make some upgrades(CAI, coilovers, brakes tires, exhaust, nothing fancy). I'm still learning and reading as much as I can. Thank you for taking the time to read my second post!

 

AFAIK, mostly it's in reference to aftermarket clutches for a manual transmission: https://itstillruns.com/differences-...h-7611018.html

...which doesn't apply to your AWD Coupe.

Anyway, that's my best guess.

 

mostly marketing mumbo jumbo

Usually Stage One refers to bolt-ons only
And not usually needing a tune
Think street appropriate modifications

Stage two are bad *** man, buy it now!

Stage three and up?
"Race Only" meant for the strip/track
and not practical for most on the street
​​​​​
But some companies label things as race only simply because they have not gone through the rigorous (read expensive) process to get them EPA approved

 

As far as I know, there are no hard definitions of stages.
I think this term originated from the turbo guys and then became a common-ish term.

 

Each "stage" depends on the manufacturer. Clutch companies were really big at doing this in the early 2000's. Stage 1 clutch, Stage 2 clutch, etc. There was no conformity between manufacturers so a ACT Stage 2 might be just as good or better than someone else's Stage 4 clutch.

When car companies had the fast compact cars (SRT4, Cobalt SS, etc) the dealerships offered staged upgrades. Stage 1 might be just an intake, where Stage 2 was a tune and other goodies, and Stage 3 might have been even more.

Basically any manufacturer today offering anything that says it is Stage 2 is just a marketing gimmick like stated above. Take it all with a grain of salt.

 

Thank you again to everyone who responded!

 

Stealthee pretty much nailed it. For example, a GTI stage 2 might be different than a stage 2 WRX; and some platforms have stage 1+ or stage 2+. Unfortunately, that means you have to educate yourself on whatever platform you're modding when buying stage 'packages' since they can differ.