10 spd vs 13 spd vs 18spd

It's not that simple.

I have a company Cascadia with the DD15 and DT12 Auto.

 

Unless you spend a lot of time running around in low range an 18 speed will give the same mileage as a 13. Bot transmissions are simply 9 speeds that can split gears, the 13 does it in high range while an 18 does it in both high and low.

Both are better than a 10 in otr assuming the driver knows how to drive for mileage in the first place.

Cummins ISX powered Prostar, 475hp/1750tq, 13 spd

 

Companies are switching to automatics because they get better fuel milage.
The tanker company I drove for tested two trucks with automatic transmissions. A Freightliner and a Volvo. They rejected the Freighliner because it kept shutting down due to emission problems.
I drove the Volvo which had a Volvo engine married to a Volvo automatic transmission; ran 48 states with it and had zero problems.
The Freightner had a Mercedes-Benz engine and don't know what type transmission.

 

The reason that 10 speeds are speced is because they are harder for drivers to tear up than a 13 or 18. People think that it is because of weight but they are pretty much bullet proof, especially for new drivers. Can you imagine a new driver getting an 18 speed and hitting every gear when they are in front of you? I have only done that a few times but I was also in the 150-160k range.

Besides, when you are hauling stuff that is bigger than the trailer mileage does not come into play at all.

 

Just disable the range selector. make the noob suffer with a 9 for a while.

I rarely split gears other than 7th and 8th. Unless I'm climbing Tehachipi with a heavy load.. then I'm usually debating the pros and cons of beating someone senseless for making me drop to 3rd when they miss a gear and stop in the middle of a pull.

 

86 10 speeds they blow, 13 or 18 is the way to go.

 

If the truck is spec'ed and driven correctly, a 13 speed is a dream come true.

Even if the truck is underpowered, a 13 speed gives the driver more options than a 10-speed for keeping the engine in the power zone (for climbing hills) and for keeping it in the sweet spot (when cruising on level ground).

 

I may be wrong but comas are going to automatic because it hard for a driver to tear them up and they get ok milage.
A 13 speed is the way to go if it's your truck and you don't pre select the gears.