Does anyone know, when I search for starter motors for my 2008 A4 B8 2.0TDI CAGA/automatic transmission it offers two power options?
The options are 1.7 kw and 2.5 kw.

Could I fit 2.5 kw starter? The car has had huge problems cranking over during the winter, already with -1 degree celsius. Changed battery 2 times, changed starter (1,7kw), changed wire loom for the starter and alternator (brand new Audi OEM). Checked charging and different parameters, all OK.
None of these made any difference and now the car almost catched fire while trying to start the engine in one cold weather, it just seem to not have enough power to crank over the engine.. Now is the starter not engagin at all and seems that some wires are melted.
Can it be that the starter motor is just too weak and I should install the 2.5kw starter?