They are definitely a good bang for buck tyre.
Federal are soon to restructure their labelling. The SS595 will be 595. A new entry will be the 595EVO, I am told they will be a touch softer than the 595's. Then there's the semi slick 595RS.
The current SS595's are damn cheap, nothing comes close in performance for the price point. i.e 235/45/17 ~$160-180 per corner.
Motor magazine did the test on the SS595's. Not the semi slicks.
I'm trying tp find out if a 245/40/17 on 8" +35 rim will fit under the front guards of a gtst. I don't really like the idea of playing with different aspect/size tyres. All though it would be nice to throw a set of 595RS 255/40/17 on rear 8" rims, they apparently fit 8" rims ok.
SLY33... Have you tried that exhaust manifold yet?