i have a 2001 weststar with c10 cat getting 9.64 gals per mile
with a 335 hp with easton slect 10 speed, it's class 8 as
a c unit, also have proheat ice gen set and this saves a lot on the engine have 49 hours of idle time on engine, sept 22,2000
per cat 250 hours on the engine equals 10,000...