SO....
The time has come for me to start minimizing the wheelspin caused by my turbo kit. A true 225 (as opposed to the undersized 225 245 stock tire debate) is not cutting it. I know I can go with 245 45 16s, not alot of options I like in that size.
I've ever heard a 255 could be squeezed on there. but it isn't recommended. The question I've got/
245 50 16 I can get g-force sports, which from my personal experience, do REALLY well when warmed up, and are very progressive, they won't just let go like some tires do as soon as they start to slide, they actually have varying range of slip, while maintaining control.
Or even a 255 50 16. I know this tire is going to be a little wider than the 245, and the 50 series, should be around 1 inch taller than the 45. My abs is currently not working (I don't believe my front sensors are there, haven't tried to track down the root cause, but the lights on regardless), so I don't think it's going to throw it off, does anyone see any other problems with me going wider and taller on stop AP1 wheels? All of these are marginal changes, and arguably within standard deviation between tire manufacturers already.

Also wouldn't mind lowering my cruising RPMS a bit, have GPS and know my spedometer will be off, and that the changes are marginal, but I would gladly take the 50-100 RPMS lower at cruising speeds.

Soo question, shortened.
Stick with a 245 45 16
Step up to a 245 50 16
Or even a 255 50 16

 

And you aren't willing to upgrade to AP2 17's because.......????

 

Its just a need right now kinda thing. I can get those tires shipped mounted and out the door for 250. If I was going to get new wheels I wouldn't want AP2 wheels.

 

Just do it. Your obviously most concerned with strait line performance. Don't expect a good handling S2k out of this. When you ready to upgrade to 17 or 18" wheels you will have more available wider and brand/compound options to choose from to maintain your handling wile improving strait line grip.

 

If I was in your situation I would wait and upgrade when I could afford a larger wheel/tire setup, probably something 17x9-17x10.

Perhaps you are looking to find a temporary setup until then, in which case I think a square setup of 245/45/16 (on four rear AP1 wheels running spacers in the front) with an aggressive tire like the Hankook RS-3 or Dunlop Direzza ZII should suffice.

I personally have a setup of four 225/50/16 Hankook RS3's on AP1 sized wheels and they seem to grip very well when it is warm and dry, but then again my car has zero power modifications.

 

http://bit.ly/IxMBdC

These with a 245 255 stager with a z2 rs3 or re11a would be my choice for your setup. If you must use the 16's do it but don't expect it to handle or grip all that well with the added power. Just be careful don't want to put all the money you spent on boost into a wall because you cheaped out on wheels and tires.

 

And they won't provide nearly as much grip as serious performance street tires (RE11A, ZII, AD08R, etc) in the OEM 225/50-16 size!

But for what it's worth, you *can* get Bridgestone RE11 in 245/45-16 if it's super important to you. But IMO the increase in drive grip with wider tires is probably not as tremendous as you might think...

Mismatching tire diameters is more of an issue without ABS than with it. With functional ABS, if you bias more to the front (which is what you'll do with larger-diameter rear tires), they'll just go into ABS sooner. Without ABS, the fronts will lock up sooner and you will increase braking distance because the rears will be doing less at front lockup. That said, more front bias is at least moving in the "safer" direction. Rears locking before fronts => bad things...

You *could* go with taller tires, but IMO it's not optimal.