I haul a heavy truck slide in camper and tow a 7000lb trailer a couple of times a month, the rest of the time the truck is a daily commuter 35 miles roundtrip all city stoplight driving. I'm looking to upgrade to a 6.7 Dually with auto tranny.

Some questions;
With the 6 speed Auto tranny, 4:10 or 3:73 gears?
What should I expect for mileage on the (empty) commute?
Does the engine brake come standard with an auto tranny?

 

I just test drove one with the 4.10's. I think the exhaust brake was at first going to be optional but is now standard.

The truck I drove had it, and together with the push button gear shift thing on the shift lever, it really worked well. Tough to tell on a test ride not towing, but it seemed to slow the truck more than the Jacob brake does on my truck.

The truck was turning around 1900 RPM at 70, which is as low or lower than my current truck with 3.73's and the NV5600 6 speed.

There's a thread on the 6.7 forum about dually 6.7 auto/4.10 milage, and one guy who owns one reported pretty poor milage, around 14. If that was mostly in town, I could live with it, but if it was mainly freeway that would get expensive.

Here's a link to that discussion.

https://www.dieseltruckresource.com/...d.php?t=149466

 

from what I've been hearing and reading, the newer ctd's are way down on mileage...probably from the epa crap