2017 may flip the script in a few key categories.

As we close in on the halfway point in what has already been a tumultuous 2017 sales calendar, we can't help but notice a few potential (and even likely) shake-ups in the sales rankings. We decided to take a look at some of the ten best-sellers in the country and see how they're doing relative to both their competitors and their own previous figures. Let's dig in.

Ford F-Series

The Ford F-Series is always the chart-topper of the U.S. auto industry and its numbers are anchored by the continued success of its bread-and-butter F-150. 2017 has been good to the F-Series, with year-to-date sales up 8.5 percent. That's no trivial number of pickups (a difference of more than 25,000--more units than some entire lineups sell in any given month).

The news gets better for Ford when you look at the pickup market as a whole. That Ford handily outsells Ram is no surprise, but F-Series is also no-joke outselling GM's entire pickup lineup. That's right; no asterisks this year. F-Series sales so far this year have totaled nearly 352,000. Combined Silverado, Sierra and Colorado sales? Just 336,505. And, according to Automotive News, Ford is doing this with the least incentive spending of any full-sized pickup seller.

Where do we see F-Series at the end of the year? Right where it is right now, barring a meltdown of truly epic proportion.

Chevrolet Silverado and Ram P/U

Now, this is where things get even more interesting. The Chevrolet Silverado line has outsold the Ram pickup line by just 5,100 units so far this year, with Ram continuing to trend upward (8 percent YTD) and Silverado continuing to stagnate (down 5.2 percent YTD). Ram was up 16 percent in May alone.

Now, there are caveats. Unlike the Ford case above, GM isn't truly in danger of losing a sales title to Ram. Even if the latter does manage to knock the Silverado out of the second-place spot, it's not going to come close to GM's total pickup sales. We'll need some Jeep Wrangler pickups before there's any chance of that. Also, Ram occupies the far end of the spectrum from Ford when it comes to incentive spending (see above), while GM is reportedly scaling back. Even if FCA can keep Ram's cash and rebate offers flowing, its volume won't be nearly as profitable.

Still, a second-place finish by Ram for 2017 would be a noteworthy coup.

Going Rogue

America is. Nissan's own Altima has tumbled nearly 17 percent this year. Rogue? Up nearly 35. And while the Rogue's fourth-place finish is plenty impressive by itself, it's what it represents for the auto industry that really matters. Fifth place? Honda CR-V. Sixth? Toyota RAV4. Americans have purchased nearly 1.2 million pickup trucks spread over just 11 model lines so far in 2017. Just the 11 best-selling crossovers and SUVs account for more than 1.2 million units, and there's plenty more volume below them.

The sedan meltdown

The Nissan Altima isn't the only four-door that is suffering. You have to go deep into sedan sales to find any good news, and so much of it is laced with asterisks that it's hard to label it that way. Camry? Down nearly 12 percent. Corolla? Down more than eight. Civic? Same. Accord? Down seven. You think that's bad? Fusion, down 26 percent. Sonata, down 28. Malibu, down nearly 30.

It is conceivable--while not terribly likely--that zero four-door sedans will populate the top ten sales slots in the United States come December.

Got anything in particular you're watching? Think we missed a big mover? Let us know in the comments.

Photo by Andrew Ganz