tire question for you dually guys

[loanman]

I just bought a 2000 F-350 Dually 7.3L with the factory 16" wheels. its time for new tires. the current tires are a 235/85-16 and I am thinking I want to go to a bigger tire to help drop my RPM's to possibly help fuel mileage.

what size tire have you guys found to be a good combination on these dually's for better mileage?

also what brand do you recommend, I was thinking of going with a bit more of an aggressive look like an all terrain

any input would be greatly appreciated as this is my first dually

thank you

[biff101]

I got the 255/85 km2. real good tire

[chrisj750]

255x85-16's don't rub each other in the back? - Spacer? If so which one?

[biff101]

mine didnt rub. maybe and inch between the tires. I added a 2" spacer to get them out to the edge of the fenders.