While much of the rest of the world is barely showing signs of economic recovery, the U.S. economy is firing on all cylinders, and a key indicator of the upbeat outlook is record full-size pickup sales in May. Although sales of fullsize trucks have been up for most of 2013 so far, May is one of the strongest months yet, with all of the Detroit three seeing year-over-year gains of at least 20 percent, and sales of Ford F-series up a phenomenal 30.6 percent for the month.

Even some of the import brands saw a strong upswing for the month, with Nissan Frontier sales surging 19.9 percent for the month. Unfortunately, big brother Titan didn't fare so well, down 35.3 percent.

Ford F-Series - 71,604, Up 30.6 Percent

As always, the F-Series sits atop the full-size truck throne, with a commanding 30.6 percent year-over-year May gain. The trim additions and minor tech refreshes added for the 2013 model year seem to have resonated with buyers, with the F-Series' sales dominance as strong as ever.

Chevrolet Silverado - 43,283, Up 25.3 Percent

The GMT900 Silverado is going out with a bang, just as the 2014 is starting to roll down the assembly lines. However, it's important to note the outgoing model has generous cash-back and finance offers available, which is likely driving most of the sales of the 2013 models. Regardless, May's performance is one of the strongest for Silverado this year.

Ram 1500/2500/3500 - 31,672, Up 22 Percent

The torrid pace may have slowed slightly for Ram, but a 22-percent year-over-year gain is nothing to sneeze at. Continued popularity of the new Pentastar V-6, along with the 2013 HD models finally rolling into dealerships, has kept the momentum up, and the coming arrival of the EcoDiesel in the Ram 1500 in the fall will keep things interesting.

GMC Sierra - 16,061, Up 21.7 Percent

The Sierra's story is largely the same as that of its near-twin Silverado. Dealers are offering door-busting deals on the remaining 2013s before the 2014 models show up on lots. If you're looking for a great deal, and don't care whether it's the latest and greatest, now's the time to buy.

Toyota Tacoma - 14,727, Up 20 Percent

Tacoma remains comfortably in the lead of midsize truck sales, up a solid 20 percent year-over-year. Incremental upgrades have kept things mildly interesting on the Tacoma, but the midsize segment is in for a major shakeup in the coming year with the arrival of the new GM midsize models.

Toyota Tundra - 9950, Up 13.5 Percent

While not showing the same gains as its domestic counterparts, the Toyota Tundra had a respectable May, with sales up 13.5 percent. But it fell just short of the 10,000 unit mark at 9950. A refreshed 2014 Tundra is due late fall, but is essentially mechanically identical to the current model.

Nissan Frontier - 6570, Up 19.9 Percent

Whether it's just a seasonal upswing, or shoppers responding favorably to the mid-year updates on the Frontier, May was a good one for Nissan's proven midsizer, with sales up 19.9 percent. Still selling less than half as many units at the Tacoma, the Frontier still has its fans as it approaches a decade without a major redesign.

Honda Ridgeline - 1626, Up 35.6 Percent

The sales of just a few more units of the Ridgeline can make a big difference in percentages, and so it was with May 2013. Modest volume sales of 1626 units was up a significant 35.6 percent. Although the Ridgeline was a bold effort when it launched in 2006, its fuel economy is no better than its more conventional rivals, with slightly lower capacities. The promised next-generation Ridgeline will likely benefit from the improvements made on the 2014 Acura MDX, with its high-strength, lighter-weight platform likely underpinning its successor as well as a new Honda Pilot SUV.

Nissan Titan - 1402, Down 35.3 Percent

The Titan continues to be the runt of the full-size litter, at least from a sales standpoint. Nissan promises an all-new model soon, likely for the 2015 model year, with a no-excuses selection of available cab, bed and powertrain configurations. Will Nissan be able to make a meaningful comeback in the full-size segment after having neglected it for so long? We shall see.

Chevrolet Colorado - 244, Down 93.5 Percent

With its fellow domestic rivals Ranger and Dakota already long past the absolute zero point, we're surprised Chevy is still moving as many Colorados as it is is. But like the Nissan Titan, GM is not letting disappointing sales keeping it from going all-in on the Colorado's successor. Expected sometime in calendar 2014, the new model (whatever it might be named) will undoubtedly be a huge improvement over the current model.

GMC Canyon - 88, Down 09.3 Percent

GMC moved only 88 Canyons in May, again, just the remaining holdover models as the Shreveport, Louisiana factory has been long since shuttered. Its successor should be rolling out of Wentzville sometime in 2014, and we expect it to be a major improvement over the current GMT355 Canyon.