What is the widest tire anyone has put on the 17" inch rim?

 

Safely or just for the hell of it?

CHECK THE FAQ's.

 

I'm assuming you're talking about the stock rim...
If so, I had the strongly unrecommended size of 245/45/17 (Dunlop
SP5000) for 1 year and 2 months. The fronts wore very unusually,
although my alignment is ok. That leaves the oversized tires to
be the cause...

I'm well aware of the tire debate and such,
so for those tempted to lecture, save your breath.
Besides, now I'm back in spec...225/50/17

 

Some have 235/45 on the stock wheels. Its out of spec but not as far out of spec as 245. 225/50 has less choices but I belive 235/45 is just fine.