I have a 2010 acura tl shawd...looking at a set of 20x10 (square) offset 35 tsw rouen in black...what size tire would i need to run...and would i need to add 5mm wheel spacer...also i enjoy spirited back road drives would that be to wide of a wheel? Also no plans to lower anytime soon...may next spring\summer...

 

anything over 9 inches wide is over kill


and why not learn to spec your tires correctly, by going to Tire Size Calculator - Tire & Wheel Plus Sizing

then there are wheel offset calculators. you can then input the offset and the calculator will spit out if you need a spacer or not..
as all it is, is math.

 

You can use those specs and be fine. I would personally run 245/35/20.

The only reason why you would need to run a spacer is if it's an O Disk rim which gives max lip but sits close to the brake caliper. Really depends on rim design.