I think 96Y is actually the correct load index for the 159, I've read somewhere that the 98 load index was either a misprint or revised.
The handbook says:
Winter tyres should be 225/50/17 ZR96 or 235/45/18 R98"
Summer tyres for 17's and 18's only come in 94 or 98XL.
When the original limited edition Ti came out the handbook didn't have any specifications for the 19" wheel/tyre combo. I could understand them sending out an addendum for that.
The load index changes with the wheel diameter and tyre width so there isn't a 'one size fits all' situation so surely it would be wrong to say that there is one load index for a 159?
Why would Alfa spec a tyre that doesn't exist (ie any recommended size but 19")?
If 96 is the correct load rating why do they fit below spec tyres on turismo models (because you can get 215/55/16 97Y)?
This is really quite important because insurance companies tend to be a bit twitchy when it comes to 'non-standard' fitments.
146 1.6TS, 156 2.0TS, 156 1.8TS, 147 1.6TS, 147 2.0TS, 159 1.9JTS, 147 1.6TS, 159 1.9JTDm, Mito 1.4, GT, Giulietta 2.0JTDm, Giulietta 1.4tb, Giulietta 1.6JTDm........