Many have questioned General Motors' logic and wisdom in committing to a midsize truck after the Chevrolet Colorado and GMC Canyon. As we recently reported, the reason we're not definitively referring to them as the "2014 Colorado and Canyon" is that the specific names for the trucks are still yet to be officially determined.

GM North America vice president Mark Reuss has gone on record saying the new midsize trucks' ace in the hole will be their outstanding fuel economy, relative to the rest of the midsize class. In the context of today's models, that's not saying much. Despite their smaller size, lighter weight, and less-powerful engines, midsize trucks are no more fuel-efficient than their full-size counterparts, and in many cases, considerably less efficient. So the rationale for the purchase of a midsize for the last few years has clearly not been fuel economy -- some customers simply don't want or need the bulk and size of a full-size truck.

The lack of a fuel-economy advantage can be chalked up to priorities, with more lucrative full-size trucks receiving the bulk of R&D money while midsize truck customers have been forced to contend with generation-behind powertrains that deliver mediocre fuel economy. In the case of Ford and Chrysler, the midsize segment has been abandoned altogether, with the Dodge Dakota and U.S.-spec Ranger departing in the last few years.

If GM delivers on its promise of high fuel economy with slightly smaller size than the 2014 Chevrolet Silverado and GMC Sierra, it will have a unique product and market proposition in the U.S. Let's take a look at where the current competition stands, and make some educated guesses at the new fuel-economy targets.

Toyota Tacoma

4.0-liter V-6 - 236 hp, 266 lb-ft: 17/21 (4x2), 16/21 (4x4)
2.7-liter I-4 - 159 hp, 180 lb-ft: 21/25 (4x2), 18/21 (4x4)

The Tacoma's popularity is most likely attributable to its broad selection of different trims and configurations, from the bare-bones landscaper's special four-cylinder regular cab all the way up to the PreRunner and 4x4 Double Cabs, as well as the street-smart X-Runner. There's really something for everyone in the Tacoma lineup.

Fuel economy is nothing spectacular, however. The base four-cylinder makes a modest 159 hp and 180 lb-ft of torque and gets 19/24 mpg city/highway in the 4x2 model with the four-speed automatic; the five-speed manual does slightly better at 21/25.

V-6 models deliver substantially more power, and have always delivered stronger performance than their rated output suggests, But fuel economy is only on par with full-size V-6 and V-8 models from GM and Ford, and substantially worse than the 2013 Ram 1500 V-6's 25 mpg highway. The Tacoma may be the midsize class sales leader, but GM has nothing to worry about from the current model in fuel economy.

Nissan Frontier

4.0-liter V-6 - 261 hp, 281 lb-ft: 16/22 (4x2), 16/21 (4x4)
2.5-liter I-4 - 152 hp, 171 lb-ft: 17/23 (4x2)

Like the Tacoma, the Frontier poses no substantial fuel economy threat, achieving about the same or slightly worse figures as the Toyota. The power/economy equation is especially pitiful with the base four-cylinder, which produces less than half the horsepower of the V-6 Ram 1500 yet still can't match it for highway fuel economy.

The much more popular VQ40DE 4.0-liter V-6 delivers robust power with only a slight mileage penalty over the I-4 model, so it's little wonder that it's the choice of the majority of Frontier buyers. But at 16 mpg city and between 21-22 highway, fuel economy is acceptable at best.

2014 Chevrolet and GMC Midsize Trucks

(Projected Powertrain Availability, Estimated Power, mpg)
3.6-liter V-6 - 300 hp, 270 lb-ft (est): 18/26 (4x2), 17/25 (4x4)
2.5-liter I-4 - 185 hp, 190 lb-ft (est): 21/28 (4x2), 20/27 (4x4)
2.8-liter I-4 turbodiesel - 175 hp, 345 lb-ft (est): 22/30 (4x2), 21/29 (4x4)

Above are our educated guesses on the powertrain lineup for GM's 2014 Chevrolet and GMC midsize models. Mark Reuss has said the trucks will not share any powertrains with full-size models, effectively eliminating the 4.3-liter EcoTec3 V-6 from the lineup. That leaves GM's widely utilized 3.6-liter DOHC direct-injected V-6 as the likely mid-range engine. With tuning specifically for truck duty, we're expecting output of around 300 hp and 270 lb-ft of torque, putting its output right in the thick of the Tacoma and Frontier's larger-displacement, port-injected V-6 engines. We're expecting quite a bit better fuel economy, with the biggest gains being on the highway, thanks to a more modern and efficient expected six-speed automatic. The Tacoma and Frontier both currently utilize five-speed automatics on their V-6 models.

The most likely candidate for the base engine is a version the new 2.5-liter direct-injected I-4 used in the Malibu and new Impala. We're expecting output of around 185 hp and 190 lb-ft and think it will easily match the Tacoma in city fuel economy, and surpass it in highway economy in 4x2 and 4x4 configurations.

The unknown factor that GM is being very coy about in regard to the new midsize models is the availability of the 2.8-liter Duramax I-4 turbodiesel in the 2014 midsize models. This is the top engine option in the global Colorado model, and has proven popular with buyers for its generous torque output. In 4x2 form, we think this engine could be capable of the hugely symbolic 30-mpg highway figure. As is the case between the Chevrolet Cruze Eco and the new diesel model, the fuel economy difference between the gasoline four-cylinder and the diesel four will probably not be huge, but the diesel will enjoy a substantial advantage in torque, probably of around 150 lb-ft.

Although we're hopeful for a manual transmission option on these new trucks, they will probably follow the pattern of their full-size stablemates and be offered exclusively with automatics. This will simplify production logistics for the trucks and allow for even greater optimization of fuel economy.

The major unknown factor on these new trucks is price. We expect them to start at several thousand more than the Tacoma or Frontier, but also expect them to come better equipped than the import models, even in base form. Figure on prices starting at about $21,000 for a base 4x2 extended cab (we don't expect a regular cab to be offered) with the 2.5 I-4. A full-boat 4x4 crew cab with the diesel could conceivably go for around $36,000, not an insubstantial sum in anyone's book. But with the expected level of refinement, content, and combination of economy and capability (the global Colorado model equipped with the 2.8 diesel has a towing capacity of 7700 lb) we think GM's new trucks have the potential to confidently challenge Toyota for first place in the midsize segment, and within 12 months of introduction, to safely surpass the Nissan Frontier in sales. Could we be wrong? Perhaps. But if GM is willing to bet big on this segment, we have a feeling they're not playing for second or third place.