The full-size Ford F-150 is the undisputed segment sales king. Over 900,000 examples were sold in 2018 alone. Meanwhile, Detroit rivals Chevrolet and Ram are duking it out for the number two sales spot with a newly initiated price war. Automotive News reports that both brands are offering serious discounts this month in what is shaping up to be a fierce battle.

"Ram Truck Month" is happening now and there are serious deals to be had, such as more than $15,000 off the previous generation Ram 1500 and around $11,000 in incentives on the redesigned current model. Chevy is not about to potentially lose its number two position quietly, launching what's called a "Silverado Sell Down" promotion with discounts of over $10,000 on the outgoing Silverado 1500.

Prefer the redesigned truck? There's also over $7,000 in incentives for that. Even GMC is making an effort with similar deals for its outgoing Sierra 1500, the Silverado's twin, and up to $4,500 off for the new truck. Meanwhile, Ford is watching its two Motor City rivals carefully but it's not panicking. Earlier this month, it was offering up to $6,000 in incentives for the 2019 F-150 XLT but no other special promotions.

And here's the kicker: the current generation F-150 dates back to 2015 though it has undergone updates recently to keep it competitive. But still, Chevy and Ram have all-new offerings whereas Ford's is nearly five years old. However, both Chevy and Ford need to pay very close attention to Ram; it is the only one of the three to gain share in the full-size truck segment since 2013.

Considering full-size truck buyers are typically deeply loyal to a specific brand, that's a huge accomplishment for Ram. For example, data shows Ram's market share has increased by 3.6 percent to 22.2 percent in the last five years. GM's Chevy and GMC, by comparison, is at 33.3 percent which is down by 1.5 percent. Ford is at 37.6 percent, down by 2.3 percent. Ram has the momentum.

Toyota and Nissan, meanwhile, share what's left. There's also another new factor that could sway buyers without brand royalty to Ram over a Chevy: the former's just revealed a very impressive multifunction tailgate. It's still too early to see how 2019 sales will play out, but Ram not only has momentum on its side but an overall excellent product that has put Chevy and Ford on notice.