I finally found a wheel with backspacing I can live with. I can choose between 17x8 with 5.5BS or 18x8.5 with 6in B.S. What do you guys think?? (06 SCrew 4x2)

 

I would get the 18x8.5s. Im more partial to the 18 anyway. They always seem to look better.

 

18's

 

either one would be a great choice. neither one will stick out to much. one factor to consider is that tires for the 18's are considerably more expensive. but if you plan to go with a wider tire say 305 mm wide or more they will fit better on a 8.5 inch wide rim than a 8 inch wide rim. I do not know what tires you plan to run but you should price them in the 17"s and the 18"s to see the price differance before buying. I myself am switching from 17"s to 18"s just becous I could not find a rim I liked in 17". but now I am paying considerably more for tires. but if price of tires is not an issue I would say either one would be a great choice.

 

I agree on the consideration of the tires but not only cost but the availability of sizes that you want. Make sure you can find a tire that you want for that size wheel and then make sure it's in a price range that you can afford. That being said, I'd go with the 18s.

 

Also this is my personal opinion. But I think any tire smaller than 33" will look better on a 17 than on a 18 inch rim. If you are getting a tire 33" or larger the 18's will look fine in my opinion. I just do not like that low profile tire look on a truck. but that is my personal taste. I guess it just depends on what you like.

 

I wouldn't be going very big by your all's standards. I'm thinking it's between running 275/70/17 or 285/65/18--something like that.