after my build , and the porting to the heads, im shooting for 20/21 freeway driving .... more would be awesome of course ....

 

im getting 10-11 mpg with my dually,doesnt seem to matter with ac on or off or city/highway milage the same,runs great,maybe time for exhaust and better breathing,it also has 11 ft utility bed on it,factory size tire was 215 and im running 235s on it could the taller tire be hurting my milage?

 

A heavy bed could be hurting it, but I don't think it would be that bad