So as I am finnishing up my rebuild and getting my truck back on the road, I'm looking into getting new wheels at the end of summer (once bank account heals). I am currently running 18x8 with 225/40 in the front and 18x8.5 w 245/40 in the rear. I found a set of wheels I like and I will be keeping the front tires the same, but I want to go bigger in the rear. So im looking at running 20x8.5 in the rear. Now to keep everything in check gear ratio wise I will need to either run 225/30 or 235/30's. Would I be pushing it with this size using it as a daily? Here is a pic of the wheels Im going to be getting.

 

I think you'll regret running that small of a sidewall tire on a daily. Im currently running a 255/35 20 on my daily, on a static drop (yeah its a good amount heavier) And I HATE IT! Hell even on the bagged Yota I don't like running anything under a 35 or preferably 40 series since I drive to shows

 

Are you worried about ride quality or protection for the wheels? Either way, thats a pretty thin sidewall to run on everyday roads.
But, on the bright side, if you ever get a flat, all you have to do is walk to the nearest grocery store and buy clump of broccoli. Take the big rubber band off the broccoli, stretch it around the wheel and you will have a "spare tire" AND a healthy snack for the ride home.

 

40 is too small...

 

thats what she said.............. I run 35's and it can be bitch. i have dinged a couple rims luckly i have pounded them out with a dead blow. I wouldnt even want to know what 30's would be like. ugggghhhh 235's would give you that extra meat on the lip to hopefully prevent any small dings.

 

I have 205/40's and the sidewall is scary small. I know a 225/40 sidewall is different, but barely bit a bit. 225/45's won't hurt. give you some protection space.

 

if your roads are anything like mine i wouldn't run anything smaller than 45.

 

Ok thanks for the input. I probably will just stick with the tire size that I have. It would be cool to have an 18/20 combo but not if im going to drive it everyday.

 

dont forget tire costs too!

for the smaller tire widths, i wouldn't go smaller than a 45, for the widass tire widths, i wouldnt go any lower than a 40. (a 265/35/18 is still skinny, but safe enough. I ran it before).

remember, the sidewall's are aspect ratios (percentages of the tread width)

205/40/16 is 40% of 205
225/45/18 is 45% of 225
345/30/19 is 30% of 345

mm/%/inch