Things used to be so clear-cut in the truck world. If you wanted a Duramax, you bought a Chevrolet or GMC. Interested in a Power Stroke engine? Navistar built it, and the Ford Super Duty was the truck you could get it in (as was an E-Series van for a while). And for a Cummins, everyone knew to buy a Dodge--er, Ram. It was the same way with transmissions: The choices were a Hydra-Matic or Allison with GM, and internally designed units with Ford and Ram. But over the last several years, that has started to change.

We first saw it on the sport/utility side (which isn't all that controversial) when ZF introduced its eight-speed automatic. This is an excellent transmission and can handle significant amounts of torque, so it's not a huge surprise that whether you buy a BMW or a Grand Cherokee, you get a version of the same transmission. But that transmission is in the Ram 1500. Don't get us wrong -- we really like that eight-speed. It's just that its use in a pickup is a definite sign of the times.

That's just the start of the controversy, though. Consider what Cummins is doing these days. In anything up to 1-ton trucks, Cummins engines were available only in Rams (and Dodges). When Cummins first partnered with Dodge, it became a key selling point for Rams. Cummins engines are so respected that many people say they drive a Cummins, not specifically a Ram or Dodge. But Cummins is playing the field, opening itself to the idea of free agency. Now that both Cummins and Nissan have announced that the next-generation Titan will come with the option of a Cummins engine, those who buy that Titan can also say they drive a Cummins. For a truck that doesn't have significant market share, this is a big, bold move. History could repeat itself, and Cummins could bring people to Nissan who might not have considered it otherwise. Yet it is strange that in 2015 you will be able to get more than one brand of truck with a Cummins, and if that company has its way, it'll be offered in even more 1/2-tons and heavy-duties. Meanwhile, neither the diesel Grand Cherokee nor the EcoDiesel Ram uses a Cummins. There isn't a smaller Cummins available that would fit in that engine bay? The previous Grand Cherokee didn't use a Cummins either, so that isn't unprecedented. Just strange. It also isn't unprecedented in the heavy-duty commercial arena, where a company that is looking at purchasing anything from cement mixers to big-rigs has a choice of engines by several manufacturers, no matter what badge is on the grille.

So why wouldn't engine and transmission companies consider doing this? They have the potential to sell more of their products, and by diversifying, ensure that their success doesn't have to rely on one automaker.

There are a few hurdles, though. First, it can be a tough sell to convince an automaker that has been building its own engines and transmissions to switch to an external company. To succeed there, the external companies will have to offer something the truckmaker doesn't have, which was how Cummins got the job with Nissan. These external companies will also have to offer their wares at a price that makes it worthwhile for the automaker, or offer a specialized engine or transmission R&D that is beyond the budgets of truck manufacturers. Also, if they do win the contract, the pressure is definitely on the supplier to make sure that quality and reliability are top-notch. If there is ever a problem, as we saw a few years ago with Navistar and Ford, the parent company will find a way to make use of global resources and bring production in-house or, if that doesn't work, go to another supplier.

What does this mean for the consumer? There are some huge upsides. When making a decision on buying a truck, having more options is better than having fewer. It makes it easier for us to get exactly what we want. The only real downside we can see is that it blurs the line some with the "here's why my truck is better than yours" arguments.

Could this be the wave of the future, where you can choose the engine you like, pair it to whatever transmission you want, and have all that in any pickup you prefer? I don't think so. Going down that road would make trucks a lot more expensive to buy. Also, I doubt that would happen in the 3/4- or 1-ton segments. Seeing a Ford powered by a Duramax? A Ram with a Power Stroke under the hood? Considering how strong brand loyalty is in the heavy-duty market, I don't see how that could work.