I am currently running a ce28n 17x 8.5 + 30 with a 245/45r17. Can I put 255/40r17 on there with no rubbing?

 

is your setup now rubbing?

 

do you have coil-overs or springs?

 

I have springs in the front wich lower it about 1". I rub slightly at full lock in the front of the tire because it is taller then stock. The 255/40 is a good amount shorter but slightly wider. would they work on the rims I have?

 

Yes, they would work with the rims you have and yes there is a good chance they won't rub anymore because they are shorter ...