The 2020 Nissan Titan half-ton and Nissan 2020 Nissan Titan XD “half-ton-and-a-half” pickups will get redesigned this year. But the Cummins diesel engine that the new XD version made headlines with is being taken off the board after just a few model years.

You might remember from the Titan XD launch circa 2015; Nissan’s revolutionary “whitespace” truck that was supposed to be more capable than an F-150, Silverado 1500, Ram 1500 or Tundra but not quite as cumbersome as a heavy-duty commercial-grade pickup. It was a decent idea, and Nissan desperately needed a hook having let the Titan languish without any significant redesigning for about a decade.

The centerpiece of the new-for-2016 Titan XD was an optional from powerplant power house Cummins, cranking out a claimed 310 horsepower and 555 pound-feet of torque. I I liked it. Now it’s going away; apparently either too expensive, too difficult to integrate with the upcoming Titan XD revision, or maybe the two companies just couldn’t cut a good deal.

A Nissan spokesperson said, specifically: “production of the TITAN XD Diesel will end in December 2019. This will help better position Nissan in the long term as we prepare for the launch of the new, dramatically refreshed 2020 TITAN and TITAN XD Gas later this year.”

Will a diesel option be back later? The company declined to elaborate. Did things get sour with Cummins? I asked that too, and didn’t get much more: “Nissan’s relationship with Cummins remains important and valuable to the company, and we are grateful for their contributions. As far as moving forward, we cannot discuss future product plans,” was the official reply.

Cummins’ spokesperson had a similarly refined answer when asked about the status of its relationship with Nissan: “Nissan has been a terrific partner. We are no longer going to supply this engine to Nissan or non Nissan customers. We will continue to provide support to existing customers,” Cummins’ PR director told me over email.

It’s hard to imagine the Cummins-powered Titan could be classified as successful after just a three-year model run. Considering what most industry analysts will tell you about truck buyers, that they’re fiercely brand-loyal, my hypothesis is that Cummins just wasn’t a big enough draw to pull people from Ford, Chevy or Ram families over to Nissan.

There was a significant uptick in Titan sales when the XD dropped, but it’s hard to draw any real conclusions from the numbers Nissan releases to the public.

What you see there is as detailed as you can get without going undercover in the company. There’s no way to examine the sales split between Titan and Titan XD, or how many people bought a diesel. That’s common in all automaker sales reports, by the way, they’re all designed to be as uninformative as possible.

The Big Three in Detroit have seemingly abandoned monthly reports altogether. But for your reference, Toyota 65,585 Tundras in 2019 so far, and the only real tweaks that truck’s been getting for years have basically been decorative.

Since Nissan’s people weren’t interested in answering the only good question I sent them (“What did Nissan learn from the Titan XD experiment; is there any angle from which it could be considered successful?”) we’re forced to conclude it that was a dud.

Now the interesting thing to watch will be resale values. Is a secondhand Titan XD diesel going to be a cheap way to get into a modern truck with a Cummins engine in a few years? I’d wager it just might.