2018 piterbilt 389 with x15

Sounds like your 565 does well pulling that much!
Good to hear its been reliable so far as well.
Have you ever pulled with a less hp motor does it do about the same on fuel or better/ worse?
Im looking into the 485 but wondered if i stepped it up to maybe 565 if it would do about the same or better on fuel because i wouldn't be working the motor as hard? If the long skinny pedal isnt down as far its not burning as much fuel right?? Lol maybe just wishful thinking

 

My company is just taking delivery of our new 2018 International LT''s, with the X15 efficiency, set at 500hp/1850tq. The dealer tried to talk the boss into that 10 speed auto and 2.64 rear end combo also. Luckily he knew better, and got the 13 speed with 3:42 rear ends (BC based company, doing Pacific NW, West Coast, Midwest). They told us the 10/16 speed and 2.64 would get 9mpg, but the first few 13 speed/3.42 trucks are doing 8.0mpg (Vans and Reefers @ 78000 gross). The mega carrier we haul for, their 485/1650 trucks with 10 speeds and 2.64 are getting 6.8 on the same run (their also programmed for fuel efficiency, ours are mid level performance factory tune).

This is similar to the experience I had, with the DD15's in my Mega Carrier trucks. Once these wiz-bang purchasers/mega carrier shops think they can get mileage out of a truck, with crazy tall rearends and messing with the tuning. All they create is a slow POS that might get better mileage going across Arizona or Saskatchewan; but they lose their ### at any sort of hill or stop and go. my 2016 Cascadia with the company spec DD15 and DT12 with 3.36 gears, would do 7.1mpg and be slow as hell. My buddies O/O 2016 Cascadia (identical truck, he got it on the fleet discount at same dealer) with the factory set DD15 505/1650 DT12 3.36's would do 8.5 all day long; and leave me in the dust.

Will report back, when I get my 2018 LT, and get some mileage numbers. If it was my money, I would get a 388 Pete with the 565/2050 and an 18 speed with 3.36 or 3.58 rears.

 

Never seen 8 mpg on my calculation. All of them were 5.5-6.8 mpg. Gross 75k lbs doubles. Running in pennsylvania. Majority of trips are on US 322 including driving 8% grade up/down and 10 speed OD auto 2.67 is useless. Like I mentioned early, strong X15 jakes is great. 130k miles no breakdown engine wise.

 

Pulled the exact same loads with a company truck for 3 years before buying my own truck. 2013 386 pete, ISX15 450/1650, 10sped, 3.91 rears with 295/75r22.5's. Ran 5-7mph slower up the hills and normally rapped out to 1800. Agv 4.8-5mpg but also had to run at 1400rpm to unload the same trailers. New truck is 3500 pounds heavier with the same trailer/load, pulls the same hills 5-7mph faster and 2-300rpm's lower, less aerodynamic, and getting just about the same if not just a tickle better economy. I was originally planning 3.73's on the new truck but the salesman talked me into the 3.58's instead. Kinda wishing I had stuck with 3.73 as it woulda bumped me up 60rpm and I think I woulda been a little happier in the hills but Im still very happy with the truck.

 

Yea, this is single 53's with skirts/tails and some with super singles. We can also only go 55-60mph on most of the run in BC; 65mph once you hit the prairies. When I get mine, I will report back, as the numbers I have now are just from our shop and other drivers.

 

That's exactly what it is. You can't change it before the warranty runs out though or you will void it.

 

Exactly. I think the only time the drive-line is different, is when you go to the 2050tq, I know the clutch, trans, driveshafts and diffs are more heavy duty (Super 40's vs 40's etc etc).

 

Yup. My driveline is HUGE and I have DS40-170 axles from DynaSpicer. 46,000 pound parts in 40,000 pound housings.

 

You can uprate your engine under warranty. You just have to fill out forms for cummins and pay a large price to get the warranty coverage for higher horsepower vs the lower horsepower coverage you currently have. Much cheaper when the warranty is over, but it still can be done.

 

My company is moving away from Paccar MX-13's to the X15 Efficiency 500/1850 in new trucks we are ordering for this next year. I'm going to be getting a 389 high top in the spring and will report back about mileage and impressions.

I've always been a CAT guy, but from what I've already seen of the X15, it's a darn good substitute in 2018. Not sure if the company is going to be getting any Performance motors, the owner doesn't like the exorbitant extra cost.