Time to buy a new semitruck, but not sure what brand

You’re kind of all over the place now. Go find a HP/T chart for your engine and post it here. I’ll bet it’s about 1450/1650 ft lbs @ 1000. 1077 ft lbs is a lawn mower

 

That’s what I’ve been saying. It’s a 410 hp 1450/1650 torque with peak torque available down to 1000. A HP/TQ chart is on the International website. I’m not flooring it at 1000 rpm and using full torque. I’m using 25-27 psi of boost. That’s 10 psi less than the maximum available to me. Those charts are telling you what the maximum available at an rpm is and that’s not how I drive. If I had the cruise on or foot to the floor I’d be pushing out 1650TQ at 1000 rpm to make about 300 hp according to their chart. I’m only using 200. That calculator I posted earlier will calculate how much torque do you need at 975rpm to produce 200hp, the answer is 1077 ftlb. 200 hp is not a lot of power and I think that’s what’s throwing you off.

 

And my boost runs up to between 45 and 62 every time I accelerate under full throttle (EDIT: should clarify high range here, so I don't get my ### chewed out, low range is always eased onto and progressive shifted) up to 1500-1550 rpm, "which means 400-470 hp" out of that little C-13 (I don't even know how you come up with some of these things) and still can manage over 5 mpg with full Canadian winter fuel pulling 84,000 lbs gross.

I'm really looking forward to the thread a couple years from now with you complaining about your motor being toast after only 300-400k miles and International giving you the run around (did you get the extended warranty?).

I learned all I know from a combination of old hands giving me direction, learning from people on this website who have 20+ years experience driving and personal experience and experimentation (i.e. finding that keeping the truck hot and where she likes to pull strong is where she seems to get the best economy).

Our main mechanic that I deal with would be slapping you upside the head for babying that motor from factory. He has said to every driver that gets a new truck, run it hot and hard for the first 50,000 miles at least to break it in properly. "Give 'er ####" were his exact words.

And guess what? Aside from some faulty sensors, every single new X15 has been trouble free since the beginning. Those three long hoods are just going through their first safety this month and have been the cheapest trucks in maintenance on the year (according to the shop manager). Even cheaper than the freaking CAT units. That's saying something.

 

Yeah that's what gets me. You spec these new trucks to run @11-1200 and think they're gonna hold together just fine. Running like that all the time I bet those liners start fretting at under 300k. New or old diesel its not very smart lugging it all the time. All that new tech and your not even at 9mpg......tall rubber with 4.42 I see 6.5-6.7 keeping it at 65 and 7.0 if I stay around 60

 

Get a 389 with the 565 HP performance X15.

Something with like a 300 inch WB, and minimum 100 inch sleeper.

 

you bring up another good point. Breaking in a motor you pretty much wanna run it like you stole it or
the rings aren't going to seat right and might even end up being an oil burner

 

Here's what I think. Now Ive never read anything to back this up and it's just a theory, but If you look at a HP-T curve for these new engines the T curve is flat as a pancake from just off idle all the way on up. I think they did that so the engines would work with automatic transmissions. Just because the engine will pull right down to 1000 rpm doesn't mean it's a good thing. It was a sacrifice made to keep an auto from shifting all the time.

 

I like your theory, makes sense after being in a shaker with dt12. It wanted to shift @1300 and bring it down to 1000. Kept that thing in manual mode.

Anyone know the torque rise is on that A26? The old maxidyne E-6's w/5 speed had a 35% rise with max torque @1050. They were built to lug and lug but if you put more fuel to them they were known to crack the block on #6

I have to get 1 more thing straight. You had a glider all spec'd out but decided to go with a new motor from the same ppl that gave us the lovely shatforce. That's one leap of faith too far for me.

 

I wasn’t confident the glider would get the fuel mileage I wanted. I read a lot about the pre emission motors and many of the claims regarding fuel mileage are overstated. This was a process that took me months to complete. I don’t trade a truck in at 350-400k like the fleets do so, it had to be the best. Only International would build me what I wanted and after researching th A26 I felt confident in it and it’s doing great.
There is no such thing as “my truck gets between 6.5-7.5 mpg” or similar statements. If you track your fuel mileage, you know what your average is. My old Peterbilt got 7.6 for the entire time I owned it. This LT is at 8.7 since I bought it November of 17’ with February through the end of last month at 8.9. The first 3 months I owned it I didn’t do that great between learning how to drive it, not having my winter cover, and break in. I expect the truck to stay in the 8.8-9 range going forward, as the running average this year is at 8.9.
I have detailed my average load in other places. I run an average of 73k loaded weight, 17% empty miles, running AR, KS, and MO to the Northeast and Southeast, back to the Midwest and back to AR and run that loop repeatedly. It is common that I’m running back forth across 44 and 70 in MO ALOT, 76 and 80 in PA, Norfolk, VA South to Knoxville back to AR, up and down 81 repeatedly, I cross Monteagle several times a month when I’m running to Atlanta and going back North. Another common run is Norfolk North to Baltimore and across PA back to OH. I’m loaded down the majority of the time, running demanding routes in congested areas and kissing 9 mpg.
As a comparison the RunOnLess campaign averaged 10.1 mpg with an average gross of only 54k and some change.
As far as lugging it all the time, I think you should read my posts more carefully. I don’t lug all the time. It’s situational and part of momentum management. I don’t care about speed and I’m not using full power, not even close, even at 975-1000 rpm. Cruising at 1050-1150 rpm in a downsped Setup is not hurting anything. It’s just cruise, when power demand is lowest; once the load on the engine increases it will shift into direct to start performing work, not sit there at max load at 1000 rpm.
I didn’t mean to start an information war here but the truck makers have done a poor job in getting information out there regarding these kind of specs. What I’m doing or recommending is nothing new and there plenty of examples of fleets doing these things with great results. You just need to spend the time reading about it. I spent 7 months researching before hitting the dealers in my area to build what I wanted.
Agree to disagree I suppose.