Tesla announced a 10-percent improvement to the top driving range for both its Model S fastback and Model X crossover Tuesday—resulting in what it claims will be EPA-official ranges of up to 370 miles and 325 miles for the two models, respectively.

The 370-mile rating will be the highest EPA-rated range for any U.S.-market electric vehicle ever. Rated range is currently at 335 miles for the Model S and up to 295 miles for the Model X.

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Tesla notes that it’s done this without adding battery capacity. To achieve the improvement, these two models have been given what could prove to be their most significant powertrain revamp since the introduction of the Model S in 2012 and the arrival of the Model X in 2015.

2019 Tesla Model X

2019 Tesla Model X

The Model S and X both get a power-systems revamp, combining a permanent magnet motor in the front—a version of the rear unit from the Model 3, according to a Motor Trend scoop—while carrying over the existing induction motor at the rear wheels.

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As Tesla notes, that new drive unit has silicon carbide power electronics, plus better lubrication, cooling, bearing, and gear designs that add up to an efficiency of more than 93 percent. Efficiency gains are had on both the output and regeneration modes for the motor, and Tesla has introduced new wheel bearings and tire designs for more incremental gains.

With the improvements, the Model S and Model X can also now take advantage of 200-kw charging on Tesla’s V3 Superchargers and 145-kw charging on V2 Superchargers, which Tesla says allows customers to regain miles 50 percent faster.

The Model S and X also now get a new version of Tesla’s air suspension, featuring fully adaptive damping for “an ultra-cushioned feel when cruising on the highway or using Autopilot,” or sharper control for dynamic driving. It adapts to the road surface, and levels the vehicle for the reduced aerodynamic drag.

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The lineup for both Model S and Model X expands, too: Standard Range versions are back, also with more range than ever. As it stands with these changes, the Model S Standard Range (285-mile range, 0-60 mph in 4.0 seconds) starts at $79,200, and the Model X Standard Range (250-mile range, 0-60 mph in 4.6 seconds) starts at $84,200. Both Standard Range versions now have a 155-mph top speed.

2019 Tesla Model S

2019 Tesla Model S

To encourage trade-ups and reward existing customers, Tesla is offering the $20,000 Ludicrous Mode option for no extra charge for current S/X owners on the two top-of-the-line Performance versions of both cars—now starting at $100,200 for the Model S Performance or $105,200 for the Model X Performance.

In typical Tesla style, this doesn’t correspond to a model year, a relaunch, or a marketing blitz, as it might at other carmakers. Instead, the changes were announced in a company blog post released after 5 pm West Coast time. The new cars could be ordered immediately, and will go into production this week.

The timing of Tesla’s announcement, on the day before what’s expected to be a difficult quarterly earnings call, is likely not coincidental. But considering all the attention paid to Model 3 and Model Y over the past year, it should serve Tesla well to remind customers and investors alike that it’s a two-platform company—and in terms of some crucial numbers it’s doing very well in keeping both platforms well ahead of anything else fully electric.