13 and 18 speeds

OMG 13 is to die for, splitting the upper range keeps the engine in the power band only a couple of hundred rpms between splits.

 

Malerose is right. I prefer 13-speed over anything else. You split the high-side gears so the RPM drop between gears is about half the normal 500 RPM.

Now I'll get beat up by some, but I don't see the need for the 18-speed in normal hauling. The 18-speed allows you to split the lower gears too. If I were running above 100,000 pound gross then I would look at it.

I believe progressive shifting and a 13-speed is the real ticket.

 

I've found splitting the bottom is nice when your loaded heavy starting out on a steep incline....

given the choice I want my 15 speed with the big hole against the dash back..

 

Hey Bigjohn, im not going to beat you up and i agree with what you said...

a 10 is great in the south east where there a no hills... a 13 speed IMO is perfect for the 80k trucks makes the hills more manageable and most of the time you can keep up a little more speed with it..

im running 105 gross most of the time and i really like the 18 speed when taking off on hills in the city it makes much easier

 

Agreee, Agreee, Agreee

 

I've got an 18. 99% of the time, I drive it like a 13. It's that last 1% of the time that I'm glad I didn't settle for a 13.

Nothing sucks worse than trying to start out up a hill and being stuck in a low gear because the step up to the next gear is too great and you'd be lugging/stalling by the time you got it into that next gear. With the 18, I can work my way up through the gears nice & easy.

 

I have never used an 18 speed, but my favorite is a 13. Splitting those top gears comes in real handy in the hills.

 

I have it on very good authority that the only difference between a 13 and an 18 is a little collar under the shift knob that falls out of the way when the selector is in high. The little collar flips back up when the selector is in low, preventing the splitter from operating.

I would rather have a 13 than a 10 any day. The RPM spread between gears is not as severe, it's easier on the drive train, shifting is smoother and fuel economy is better. I have driven 9, 10, Super 10 and 13. I have no need for 18 because I do not haul over 80K and I do not run "off-road" hauling logs and such.

Many of the megas run 9C (convertible to 13 or 18 ) trannies because, a 13 would be too complicated for most noobs and after they take it out of the fleet for sale, they convert it to 13 for resale value. Of course, some gears will have to be replaced after being ground to nubs by students, but only half of them.

 

IIRC the gears are different ratio on the low side of the 18 versus the 13.