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2018 Mazda6 Deeper Dive | Talking torque steer, NVH — and why no manual?

310 pound-feet? How'd you deal with all those torques?

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The 2018 Mazda6 isn't just a styling tweak and a bigger engine. Mazda insists that it wasn't "reskinned, it was re-engineered." Very well, let's take a deeper dive into what exactly was done.

Of course, the headlines will inevitably be devoted to the new 2.5-liter turbocharged engine that grants the current-generation Mazda6 what it has always lacked: an engine upgrade. And what an upgrade it is, boasting 265 horsepower and 310 pound-feet of torque. That latter number, as we can figure, will make the Mazda6 the most torque-rich front-wheel-drive car on the market. Only the front-drive Mazda CX-9 and Lincoln MKX/Nautilus matches or betters it.

However, that engine and its relatively prodigious torque do bring up some questions. First, how will it not have catastrophic torque steer? Though changes were made to the suspension and steering for 2018, mostly to increase refinement and reduce NVH (see below), they also serve to quell torque steer. However, according to Mazda engineers Jay Chen and Yoshiaki Yamane, the 2.5-liter's torque delivery was carefully tuned to gradually and smoothly build. The goal was to create a "sophisticated" and "accurate" power delivery as opposed to a more energetic one. This is not the rebirth of the Mazdaspeed6. Was it successful? Well, we'll have to wait to drive the car to really find out, though recent efforts to reduce torque steer without all-wheel drive have certainly cleaned things up from the bad old Saab 9-3 Viggen days.

The other question you might have is: Why no manual with the turbo? Apparently, that same gradual and smooth torque delivery really doesn't pair well with a manual transmission, and specifically, the acceleration tendency to leave the engine higher in its rev range. Mazda's existing manual, even one paired to a diesel engine, just wasn't intended to handle the 2.5 turbo's added torque and its specific torque delivery. According to Chen and Yamane, it wouldn't deliver the superior and more refined drivability Mazda is trying to achieve. Let's also not ignore that the minuscule take rate probably wouldn't have made it worth Mazda's while.

Yet, moving beyond the new engine and rather difficult-to-spot exterior changes, the most significant improvement for the 2018 Mazda6 is the reduction in noise, vibration and harshness. This was achieved with a thicker floor plan, a flat underbody tray, additional door seals, more robust NVH countermeasures in the doors, and the aforementioned chassis changes. It's actually similar to what was done for the all-new Mazda CX-5 (see the Related Video below for everything that was done there), and if it's indeed similar to that car, the new 6 should be very quiet.

Other NVH countermeasures were made for the revised naturally aspirated 2.5-liter four-cylinder, specifically because of its distinctive cylinder deactivation system. One, since we were wondering, is the choice to shut down the outboard cylinders — keeping the inboard ones engaged limits the amount of lateral motion and therefore vibration that would otherwise be created.

There are also changes to the interior to help further Mazda's efforts to move into a more premium space, though like the exterior, we can't say it's easy to spot the visual differences. In any event, it's still a handsome cabin.

Now, will all of this be enough to finally put the Mazda6 on midsize sedan shoppers' radar? Ah, we have doubts anything could do that, especially with the mass exodus to small crossovers. But hey, it definitely doesn't hurt.

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