Despite the fact that GM’s new midsize pickup trucks are about to get a diesel engine option, Toyota‘s all-new Tacoma will not.

Speaking during a live chat, Tacoma and Tundra chief engineer Mike Sweers was unequivocal. “We will not be offering a diesel engine,” he said. “We’ve looked at diesels, and diesel is a difficult topic right now because of the new Tier 3 emission regulations.”

Those Tier 3 regulations, set in place by the Environmental Protection Agency, are set to take effect in 2017, further reducing tailpipe emissions and, as a result, making diesel-powered light vehicles harder to pass, not to mention more expensive to build.

Sweers is aware of the obvious advantages of a diesel engine. “Diesel, from a fuel economy standpoint, is about a 30 percent improvement right out of the box,” he said.

However, that’s not enough to offset the negative aspects of diesel engines.

“The downside to diesel is the emissions has to be certified at the same level as a gas engine,” said Sweers. “So the way to do that is you have to put on an after-treatment system.” That system, he claims, would add as much as $3,000 to the cost of a vehicle.

“So if we consider that cost, versus the fuel economy improvement, and the fact that diesel is $1 more per gallon more than gasoline, is there a return on the investment,” asks Sweers rhetorically.

Even if the answer is yes, Sweers wouldn’t bet on diesel tech for the future, pointing to further emissions regulations taking effect in 2019 that could then shelve certain engines. “Can you make that diesel survive? Is it a two-year engine? Is it a four-year engine? That’s the question,” said Sweers. “It’s very difficult to show a return on that investment.”

Instead, Toyota will continue to focus on gasoline engine options for the Tacoma, with a 2.7-liter 4-cylinder as well as a new 3.5-liter V6.

It is powered by a “segment first” 3.5-litre Atkinson Cycle V6 with 270 hp. The other engine is the base 2.7-litre inline four-cylinder currently available on the Tacoma.

For the models that do make the cut, prices start at $22,200 for the Access Cab SR 4×2, which is $1235 more than today’s cheapest Tacoma model, though that price now includes a six-speed automatic transmission to go along with the 2.7-liter four-cylinder engine (five- and six-speed manuals are reserved only for 4×4 models). At the top of the range is the $39,375 V6 Limited 4×4. Some 28 other permutations are planned, combining the Taco’s two available cab lengths, short or long bed sizes, four-cylinder or V-6 engines, and two- or four-wheel-drive powertrains. Scroll to the bottom for the full rundown, but note that these are the MSRP prices, presumably not including the destination and delivery charge (currently $885 for 2015 models).