Interesting

Hmm......

 

Old company bought a bunch of those new X15's last year. 505/1850 Efficiency motors with 13-speeds. About a year ago, couple friends of mine came back together on the 17 in Ontario.

One truck was X15E (13/3.73), other was a ("modified") 510/1850 Paccar MX-13 (18/3.73). Cummins was loaded around 90k, Paccar was 95k. Cummins couldn't keep up with the Paccar if it's life depended on it, and it wasn't a driver problem. Motor was properly broken in too.

I wouldn't be surprised if they are reporting flywheel horsepower/torque and not ground power, because they want to have higher economy numbers to get sales.

But the new MP8 seems to be running away from everyone. Guy I follow on Instagram just did a trip last week down the I94 from IL to OH or something, 10.1 mpg at 79,980 gross with a tanker. Had the software screenshots to prove it (with GPS mapping).

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My experiences with Mack's was kind of muddied because of how Paul's under-powers their trucks. The fact I could even get 139,900 lbs gross up to 100 km/h with a 338 hp motor shows the tenacity of those motors.

 

Fake news ..... a Mx couldn’t out run anything...ever.

 

MX driver couldn't believe it either. Must have been something wrong with the X15.

EDIT: And I've driven a ("modified") 510/1850 MX-13 pulling B-trains. It pulled as strong as any 475 C-15.

 

For sure! It'll be a triple digit truck when I'm done. Those 5.29 rears are long gone. With a single 3.73 rear and OD 15 in it on tall 24.5's it should just break 100 MPH at 2,000 RPM.

If you've got any more pictures of the truck kicking around I'd love to see them. Plan is once its done is to put some of its history on a board that I can display at any shows I take the truck to.

 

Here you go $163K ......heavy spec but wtf...?

 

That's funny. You must have way better ISX's than the ones we have because out stock C15 475's will pull 10 KPH more up the hills than our ISX 600.
You are right about the Jake though. Cummins has always ruled here, right from the NTC days.