We learned a lot about the 2019 Mazda3 hatchback and sedan when it made its debut at the L.A. Auto Show . It will still have a manual transmission, it will offer all-wheel drive for the first time, and it's a stunner inside and out. But we still had questions about some of the details, so we spoke with folks from Mazda , including a couple of engineers for details on engines, suspension and drivetrains.First off, of the five engines announced for the Mazda3, just two of them are slated for the United States. At launch, the Mazda3 will be offered only with a naturally aspirated 2.5-liter four-cylinder. It's mechanically pretty much the same as what you'll find in the Mazda CX-5 and Mazda6 . It even features cylinder deactivation. The only real difference between this engine, its predecessor, and the one in other Mazdas is some minor engine tuning tweaks. Power is almost the same with 186 horsepower and 186 pound-feet of torque, gains of 2 horsepower and 1 pound-foot. Fuel economy is rated at 27 mpg in the city, 36 on the highway, and 30 overall for front-wheel-drive models. We would expect the all-wheel-drive model to have slightly worse fuel economy simply due to extra weight and having to power two extra wheels.The Skyactiv-X engine will become available later in 2019. It will be rolled out in Europe first, with America coming after. When it does come here, it will be offered in states with stricter emissions regulations before coming to other states.While we're on the topic of engines, we also probed a bit about the possibility of the turbocharged 2.5-liter engine coming to the Mazda3. We did get the typical response of not being able to comment on future product. However, they did confirm that the turbocharged engine does in fact fit in the new Mazda3, since it and the naturally aspirated engine are very similar, and the naturally aspirated engine still uses an enormous header, meaning turbo plumbing wouldn't be an issue. Everyone we spoke with at Mazda did emphasize that they are listening closely to buyers, which is what led to the turbo engine being offered on the Mazda6 and CX-5 , as well as the introduction of all-wheel-drive to the Mazda3. So, if you, like us, want to see the turbo engine added to the Mazda3, let the company know. They might just do it.Now as for drivetrains, the company is still deciding which trims and which combinations of engines will be offered. Naturally, a manual has been announced, and with the 2.5-liter engine being the standard engine, that will be a combination for sure. The manual does indeed couple with the all-wheel-drive system, so that's a possibility, too. And manual and automatic transmissions work with the Skyactiv-X engine. So all combinations are possible, but Mazda is determining exactly which combinations will be offered.This all-wheel-drive system we've mentioned is interesting, too. Mazda has engineered it to work in tandem with the G-Vectoring systems. In case you're not familiar or don't remember, G-Vectoring cuts power briefly at turn-in to shift weight forward, increase the contact patch of the front tires, and generally make the car more eager to enter corners. G-Vectoring Plus, which will be on the Mazda3, adds a dab of brakes to the outside front wheel to help the car straighten out more readily on corner exit. What happens with all-wheel-drive, is that the rear axle is decoupled from the engine as the car turns in. The engineers found that the drag from the rear wheels and drivetrain made the car more reluctant to turn. Then, as the car straightens out, power is returned to the rear wheels to again help it on corner exit.Finally, we come to the rear suspension. We were surprised to see the Mazda3 abandon a multi-link rear suspension in favor of a torsion-beam rear end. Torsion beam suspensions are generally considered less capable and refined since it ties both wheels together. Sometimes it's used because it's cheap to develop, or because it's easy to package. Everyone we spoke to at Mazda said that this design wasn't chosen for those reasons, but rather because they were able to make the car ride and handle better. The company found that the design offered more natural reactions to bumps for the passengers inside, and the company was able to really dial in every single part since it was a simpler suspension with fewer variables to worry about. For example, one of Mazda's engineers mentioned that each side of the multi-link suspension had 10 bushings to mess with, and the torsion-beam setup has just one on each side for the trailing arms.We'll be able to let you know whether all of this fancy engineering makes the Mazda3 a better car when we get to drive it in person. That won't be very long either, as we'll have an opportunity early next year. So stay tuned for a full review in a few months. And in the meantime, keep telling Mazda to give us the turbo engine!