not this again!

try a search mate as mk4 golf buying advice is asked every few weeks and theres loads of info on here about them.

As said above about telling what is what, only red di's can also be 115 and the all red tdi wasn't used on a golf it was just badged gti.[150]

gt tdi will either be a 130, 115 or a 110.

be warned though badges can be changed easily, the best way is to check the engine code, - try a search i'm sure i've written a comprehensive list of what means what before.