In what the car's instrumentation describes as "Insane Mode," Tesla's all-wheel-drive, 691-horsepower Model S P85D electric sedan can reach 60 mph from a dead standstill in just 3.1 seconds. Humiliated drivers of conventional sports sedans are left sucking, well, not exhaust fumes but clean air. Welcome to the new, eco-friendly paradigm of ass-kicking. No shifting of gears, no significant noise. Just bury your right foot and make the jump to light-speed.

We planned to push these plug-in players as hard as if we were testing Porsches.

But can the Tesla Model S P85D and its twin electric motors handle a genuine road trip? You know, romp for a few hours on winding country roads where there isn't so much as a AA battery for 100 miles in any direction?

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To answer that worthy question, West Coast editor Michael Jordan and I departed Los Angeles in a new P85D and ventured north toward the rolling hills and bucolic fields of California's rural Central Valley. And because one cool ride is never enough, we also brought along another cutting-edge variant on the Tesla theme: the Saleen GTX prototype, a Tesla Model S extensively modded by longtime Mustang and Camaro tuner Steve Saleen. We planned to push these plug-in players as hard as if we were testing Porsches, all the while straying as far from "socket security" as we dared.

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Before we'd even started our drive, we topped off the batteries at the Tesla Supercharger station near the Tesla Design Studio in Hawthorne, one of the free, fast-charging electric terminals that Tesla has erected around the United States, Canada, Western Europe, and now even Australia. One thing became patently clear almost immediately. In a state where the profile of the Tesla Model S is now as commonplace as palm trees, sushi joints, and arugula-trimmed burgers, Saleen's candy-apple-red GTX draws applause like a Ferrari. Even employees from the adjacent headquarters of SpaceX thought they recognized the shape of the car but weren't entirely sure. "Is that … a Tesla?"

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"I want to do what AMG does for Mercedes," Steve Saleen had told me when I picked up the GTX prototype the day before at Saleen Automotive Inc. in Corona, California. "Better performance, more creature comforts, dramatic styling." To that end, Saleen takes a Model S and adds new front and rear fascias, a carbon-fiber front aero splitter and rear diffuser, 22-inch forged aluminum wheels, a custom leather

interior ("with a cupholder!" Saleen points out), carbon-ceramic brakes, and a sport suspension. The electric motor(s) and liquid-cooled battery pack are unchanged, but for enhanced acceleration Saleen replaces the stock transmission with a 11.39:1 ratio for the final-drive that features straight-cut gears, which happen to emit a whine that reminds you of a spacecraft from "The Jetsons."

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Built last year and later shown at the SEMA automotive aftermarket extravaganza, the Saleen prototype we're driving (based on a rear-wheel-drive P85) was dubbed Foursixteen at the outset, which expressed its horsepower rating. Then Elon Musk's intrepid crew went and upped the output of the car with a software upgrade. (D'oh! Stop production on the Foursixteen badges!) Saleen will now build a GTX off any Model S variant you want (see above)—including a high-performance version based on the studly all-wheel-drive P85D. With every bell and whistle added, the P85D version of the GTX goes for an eye-watering $165,000. But Saleen thinks he'll be able to entice more than a few Tesla owners to pony up for the exclusivity and style of his GTX. "It's just $30K-$35K more than a loaded P85D," he says.

You're involved. Like a private pilot, you plan ahead—how far are you going, where are the recharging stops, what are your reserves and alternates?

Cruising up Interstate 5, we escaped the L.A. sprawl and began the lengthy ascent past 4,000 feet into the fabled Grapevine and through the Tejon Pass. Observation No. 1: Wow, it's nice having so much electric torque on tap for an uphill grind like this. Both Teslas made the climb feel effortless. Observation No. 2: Splurging on all that torque spikes the energy consumption, and the car's estimated cruising range falls noticeably. Observation No. 3: The "futuristic" whine of the GTX's straight-cut gears is cool—for about five minutes. Then you just want it to shut up. (Saleen offers quieter gears as an option.)

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By the time we reached the Tejon Ranch Supercharger station at the end of the pass in Lebec, we'd traveled about 90 miles, most of it steeply uphill. Starting with "full tanks" of around 250 miles of cruising range, both cars now showed well over 100 miles of range left. Jordan and I plugged our rides into the free "pumps," grabbed some coffee, and sat in the sunshine to chat with a few other Tesla owners also recharging. And it's right then you notice: As a Tesla driver, you're part of a community of pioneers. During recharges, they all have a story to share about their car—how much they like it, how far they've driven. (One woman told us that the string of Superchargers clear to Canada help her commute regularly from the state of Washington to San Diego.) This enthusiasm bubbled over at the sight of the GTX. "Looks sensational" was a frequent comment.

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An easy 40 minutes or so later, Jordan and I were back on the road in the twin Teslas, batteries full. As we discovered over the next two days, stopping at the Superchargers (they're easy to find in California) actually makes travel more enjoyable, not less. You pause, have a coffee, maybe throw down a picnic basket of fried chicken, maybe strike up a conversation with a like-minded pioneer. Why skip across the landscape and be left with memories only of freeway signs? Stop. Take a look around. Enjoy.

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On one of the Central Valley's fantastic, lightly traveled winding roads, I was able to push both cars hard in a little back-to-back driving exercise. Both handle brilliantly, far better than you'd expect of four-door sedans that weigh nearly 5,000 pounds. Sweet steering, lots of grip. And, of course, the all-wheel-drive P85D is just dazzlingly fast. At least it is until the powertrain heats up, at which point the performance drops off noticeably. Interestingly, Saleen claims improved airflow and cooling for his GTX, and while the rear-wheel-drive car isn't as quick from a standstill as the P85D, it maintained its performance better. (Remember to turn off the powertrain's setting for creeping at idle in order to get quickest getaways.) In any case, both Teslas prove that our electric-car future hardly means the end of driving thrills.

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My heavy right foot took its toll on cruising range, all right, but did I panic, did range anxiety at last gain the upper hand? Not at all. A simple glance at the Tesla's huge, 17-inch touchscreen shows all the nearby Supercharger stations (and conventional electrical hookups) on the navigation display. "Let's see, there's a station about 50 miles from here. The car shows some 80 miles of range left. Easy."

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And that, in a nutshell, is the Tesla Way. You don't simply drive with the assumption of bumping into a fuel station when you need it. You're involved. Like a private pilot, you plan ahead—how far are you going, where are the recharging stops, what are your reserves and alternates? Thanks to the abundance of Tesla Superchargers—and the ease of finding them using the software built into the nav—trip planning is effortless and even fun.

With these cars, you're immersed in the driving experience. Isn't that the very definition of "enthusiast"?

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2015 Tesla Model S P85D Specifications

Price: $106,200/$110,500 (base/as tested)

$106,200/$110,500 (base/as tested) Motors: AC induction, 221 hp, 244 lb-ft front; 470 hp, 443 lb-ft rear

AC induction, 221 hp, 244 lb-ft front; 470 hp, 443 lb-ft rear Transmission: 1-speed automatic

1-speed automatic Layout: 4-door, 5-passenger, dual-motor, AWD sedan

4-door, 5-passenger, dual-motor, AWD sedan Suspension F/R: Control arms, coil springs/multilink, coil springs

Control arms, coil springs/multilink, coil springs Brakes F/R: Vented discs/vented discs

Vented discs/vented discs Tires F/R: 245/45R-21 Michelin Pilot Sport

245/45R-21 Michelin Pilot Sport L x W x H: 196.0 x 77.3 x 56.5 in

196.0 x 77.3 x 56.5 in Wheelbase: 116.5 in

116.5 in Weight: 4,830 lb

4,830 lb 0-60 mph: 3.1 sec

1/4-Mile: 11.6 sec @ 115.2 mph

11.6 sec @ 115.2 mph Top Speed: 155 mph

155 mph Cruising Range: 253 mi

Decoding the Tesla Model S

With the crew at Tesla constantly tinkering with its lineup of model variations, keeping track of current offerings can be confusing. Here are the four variants of the Tesla Model S that are available from the factory now.

70D: 329 hp, all-wheel drive, 70-kW-hr battery, 240-mile range, 0-60 mph in 5.2 sec

85: 362 hp, rear-wheel drive, 85-kW-hr battery, 265-mile range, 0-60 mph in 5.4 sec

85D: 422 hp, all-wheel drive, 85-kW-hr battery, 270-mile range, 0-60 mph in 4.4 sec

P85D: 691 hp, all-wheel drive, 85-kW-hr battery, 253-mile range, 0-60 mph in 3.1 sec

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The future of Tuned Teslas

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In 2012 when the Tesla Model S first began to roll off the assembly line in Fremont, California, just 3,100 were sold. In 2013 some 22,450 examples of the Model S hit the street. In 2014 the number climbed to 31,623, and now monthly sales of the car have surpassed those of the Nissan Leaf. That's a lot of cars, so it's no wonder aftermarket companies such as Saleen are interested in making Tesla hot rods.

Unplugged Performance (UP) has been developing a series of enticing add-ons for Elon Musk's electric baby from its shop down the street from the SpaceX facility in Hawthorne, California. Order your new Tesla Model S directly through Unplugged Performance, and the company will add its own body pieces, including a redesigned front fascia, rocker-panel skirts, rear spoiler, and a lighting kit. UP also offers 21-inch BBS wheels, the same diameter as Tesla's largest rims. "Unplugged Performance is positioned to have a similar relationship to Tesla as Brabus does to Mercedes-Benz," says Ben Schaffer, president of Bulletproof Automotive, which is UP's parent company.

If you want even more juice from an UP-modified Model S, you can order it in Unplugged Performance Electric Blue, which is laid down during the car's initial assembly at the Tesla factory. Trim pieces in carbon fiber and wood liven up the cabin. The first UP Tesla has already been sold to a customer in Brunei, and the company has opened a dealership in Japan. Tesla's factory warranty remains intact.

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We're guessing there isn't a factory warranty for the XchangE (pictured), a concept car designed by the visionary Swiss firm Rinspeed that debuted at the 2014 Geneva auto show. While the exterior looks like a subtly tricked-up Model S, the interior has been designed to rival first-class air travel. Even wilder, Rinspeed claims the XchangE is fully autonomous, featuring aircraft-style "steer by wire" technology. When it's not in use, the steering wheel even slides out of the way to the center of the dash.

The XchangE's infotainment system powers four interior displays, including a 32-inch 4K-resolution monitor. A plexiglass moonroof is overhead, while nearly 500 LEDs provide ambient lighting. Rinspeed says passengers will be able to hold a business meeting at freeway speeds while brewing espresso. This is either the best thing ever or your worst nightmare, but don't expect a fully functioning demo unit to be ready anytime soon, no matter which side of the autonomous fence you're on. -- Rory Jurnecka