Transmission choices

Honestly i would go with an 18 speed or 13 speed at a minimum as an O/O. They give a lot more flexability then a 10 speed or even a auto in my opinion. As an O/O you never know when you will be kicked to the curb for a company driver or need to leave once work dries up and have no clue what may be coming down the pipe later. Having an 18 and say 46k rears gives you more options without adding a lot of weight. Say your tanker job goes tits up and you find a job hauling overweight flatbed loads for instance. Having an 18 speed gives you the option to grab those loads and the lower gears to get and keep it moving much more easily. While a 10 speed or auto might work here an 18 will be far more user freindly.

That said in terms of durability and reliability you wont notice a huge diffrence between a 10 13 or 18, or even an auto. You will see a slight to moderate mileage bump with an auto though. That said considerimg the current state of computer chips and companys taking a "if its even somewhat in some shape close to a pass sell it" stance on QC atm....well i sure as hell wouldnt feel safe letting a computer dictate how to shift my rig for me.....especially loaded on a hill.

 

IDK.
I'm running an 18spd hauling 129k and I mostly drive it like a nine speed. I could split the gears and maybe top a hill at 3-4mph faster but it really sucks the fuel doing that. (keeping the rpm between 1700-1900 rpm for the peak HP that is)
A 10 spd would probably fit the bill as a nice in between.

I pull it up a couple of 8% grades and there isn't much difference between 18 and 9. Maybe on those annoying long gradual incline grades and extra gear could be a "perk", but it's isn't a game changer, IMO.

 

Auto shifts are computer controlled. Anything that has a computer involved I try very hard to stay away from. Not much choice on the motor having a computer. Having pulled smoothbore general chemical and milk with both auto shift and standard I would stay very far away from the auto shift. R&L has gone mostly to auto shift and there were lots of issues with the. Though it did seem to be a hit and miss across different makes and models

 

18 speed is the best.

 

Buy a 18 speed for the same reasons Artic Fox stated if you don't need all 18 .drive it like a 9 speed then.. I love my 18 speed wouldn't have it any other way ... its just like the terminology ..."Friends with Benefits".... they're there when you need them ...there're not when you don't

 

A automatic in truck pulling a tanker, especially a smoothbore will beat you and your truck to death. At least with a manual you can somewhat control the surge.

 

A 13 will do just fine. Manual over an “auto” any day. I have an 18, never really seen the need to split the lower gears. Usually just split the top two when loaded.

 

The thing that I like about the 13s and 18s is that in low traction conditions, the 8 gears on the top give a driver worlds more options and control. Feel the tires spin, drop a gear. Repeat until you get to the top of the incline.