First Time Ordering New Rig - Advice?

With the Performance series X15, I would gear a little shorter. 3.42 or 3.55's with LP 22.5. Don't really want to lug them like Cummins suggests all the time. If planning on aftermarket exhaust, may even go to 3.70 ratio. Suspension I would go with the AG400L, it is same as Peterbilt Low Air Leaf. Very simple 4 bag suspension that holds up well to heavier weights. With Aero cab, curved glass is only option. I like one piece for visibility as wipers park down. Going with disc or drum brake?

 

3;36 with the big rubber, 18 over, 565 with 2050 torque. Just WOW! I'm running a 605 2050 torque, couldn't chase you.
I'm using 373 gears because of my application. I have the small rubber. I would prefer a 390 ratio with big rubber though. Running a reefer with the 3:36 and big rubber will give you a ratio to the road at 3: 23. The torque in your engine at 2050 will pull you deep into the grades before you may have to split back, especially with 80,000 gross.

 

Here are all options. Prices are list, not actual.

 

With an emmissions engine you're definitely going to want an APU, they don't like to idle apparently. You definitely don't want the couch instead of the bed, they suck to sleep on. There's plenty of room for a couple dogs with you with a 72, unless we're talking miniature horse sized dogs.

 

With the Performance series, seems like the taller gears are not turning into real world fuel efficiency numbers. The W900L will never get good fuel mileage. Period. The X platform has known issues of liner fretting. Lugging and producing lots of torque at lower RPM amplifies the issue. I would bump cruising RPM up 100 from their recommendations. Make sure they turn off road speed governor and idle shutdown timer. Might want to look into getting laptop with Insite too.

 

If you just have to get a W9 then get the 86. They sell as fast as they are listed on the used market.