What is up with the questions about gearing?

The National lease affiliate we deal with is getting us (and others) 3.25 rears and transmissions that in high gear pull 5 mph per 100 rpm, 75 at 1500 rpm.

I'd like an 18, but in top gear, the ratio is the same, I've driven 18s, too.

The engines with down speed specs pull better at lower rpms, I can feel the difference from a 2018 Evolution to the 2013 I put 460k on from new, and I thought that one was good.

Now the reason for the 18 over a 13 is in driveability at lower speeds and in reverse, it's easier to control and shift in adverse conditions, and you don't have that big gap between the low and high sides like a tall geared 13 had.

The newest 13 I have driven was a 2005 Western Star, the best truck was a 2003 525 hp N14 powered FLD 120.

I drove an older one that had been regeared with a higher ratio, Red Top Cummins (who knows what horsepower by then), and it was gueared with I'm guessing 373 or 390, by the speed and it did pull better with less shifting, I really liked the 18 spd for what we did going to farms off pavement. Then, I got a 13 speed with a Detroit, and drove that Western Star after that. Then came the nightmare of the Eaton Ultrashift.

The company, when they bought trucks new, always got upscale specs, but they bought used trucks later, with direct drive 10 speeds. The power dividers won't last as long doing heavy work, even though the final ratios are the same because of gearing in the transmission, we had 5 of them, and all lost the power divider before a million miles, the ones from wrecks didn't last, but a new one did. The manual claimed the 10 speeds were good for up to 140k gvw. These were Rockwell.

Another thing, the less losses from friction translated to getting away from you more quickly on a downgrade, in gear. I noticed that difference pretty quickly.

I'd rather have a 9 than a 10 because of mph at the range shift, but I've now driven far more miles with 10 speeds than anything else.