In an effort to simplify its assembly process and boost production rates, Tesla Motors has streamlined its 2014 Tesla Model S electric-car lineup and eliminated several variants.

Specifically, the California carmaker will no longer offer its P85 and P85+ performance versions in rear-wheel-drive form--those models will only be available now with Dual Drive all-wheel-drive.

DON'T MISS: Motor Trend Reviews Tesla P85D, Drools & Froths Uncontrollably

And the version of its electric sport sedan with the smaller 60-kilowatt-hour battery pack will not be offered with all-wheel drive at all, eliminating the "60D" version as well.

"This helps us streamline the manufacturing and supply chain logistics and enables us to better ramp production," Elon Musk told analysts during Tesla's recent third-quarter earnings call.

Tesla Motors CEO Elon Musk reveals Tesla Model S 'D' all-wheel-drive system, Oct 2014

The model cuts leaves Tesla with a lineup of four cars: the rear-wheel-drive 60- and 85-kWh versions with one motor, plus the dual-motor all-wheel-drive 85D and P85D.

Halo car deep-sixed

Tesla also reduced the number of colors available--bye bye, green and brown--and eliminated various options.

ALSO SEE: Tesla Reveals 'D' All-Wheel-Drive Model S, 'Autopilot' Feature

The now-departed Model S P85, with 416 horsepower and a 4.2-second 0-to-60-mph acceleration time, was the high-performance halo car that wowed car magazines and has starred in YouTube drag videos since the Model S first hit the marketplace in July 2012.

2014 Tesla Model S

The P85+ version had similar performance, but better high-speed handling due to wider rear tires and recalibrated suspension.

Both cars were superseded by the 691-hp all-wheel-drive dual-motor P85D, whose 0-to-60-mph acceleration is quoted at a mere 3.2 seconds.

Yawning price gap

While performance-at-all-cost types won't miss the P85, its disappearance leaves a $20,000 price gap between the P85D (at a $104,500 base price) and the next-cheapest model, the standard AWD 85D ($84,900).

The old P85, at a base price of $93,400, represented less than half that price premium over the 85D.

MORE: Tesla Model S Dual-Motor Is Quicker, Has Higher Range Too: How Do They Do That?

Then again, it also represented only about half the performance step-up.

Will that hefty premium discourage on-the-fence performance-seekers from stepping up to the P85D?

2014 Tesla Model S in China

Not necessarily. The performance sub-brands of German luxury makes--AMG for Mercedes, "M" for BMW, and so forth--traditionally carry quite stiff premiums over the standard versions of the same car.

Still, we wonder how many Model S buyers might have preferred that middle ground: $8,500 extra for 4.2-second acceleration, rather than $20,000 for the "Insane" 3.2-second performance of the P85D.

Insane performance, and price

(Yes, the P85D's most aggressive driving mode is actually labeled "Insane" on the touch-screen mode selector.)

RELATED: Life With Tesla Model S: At Last, Some Maintenance Needed (New Tires)

"In a way, it's forcing the customer to self-examine and more seriously define what he wants out of the car," a Tesla sales rep told me.

"You can't be just a little bit crazy any more. You've got to go totally insane."

At a totally insane price, we might add: A full-spec P85D goes for $138,000-plus.

2014 Tesla Model S

P85D buyers will at least have the option of spending "only" $104,000. Tesla originally announced that the P85D would come standard with 21-inch rims, high-performance tires, air suspension, and other goodies that pushed the base price above $120,000.

But in response to customer squawks, Tesla has now "de-contented" the base version, fitting it with coil suspension, standard 19-inch wheels, and regular all-season tires.

Those are the more sensible, reasonable choices, of course.

To select instead the wildly expensive, delicate, 21-inch rims; the wildly expensive, fast-wearing, temperature-sensitive, blow-out-prone performance tires; and the Rube Goldberg air suspension would be.....insane.

No 60D

Also eliminated, after a brief theoretical lifetime of a few weeks, was the all-wheel-drive dual-motor 60-kWh version of the Model S.

2014 Tesla Model S 'P85D' all-wheel-drive model

At a base price of $69,900, Tesla apparently decided to maintain the 60-kWh model's role as its no-frills entry-level car.

The 60D, however, could also have played the role as Tesla's greenest model. With a lighter weight due to its smaller battery pack plus the more-efficient dual-motor drive, a 60D would have been the most efficient Model S of all.

Anyone who ordered a 60D during its brief period of availability is out of luck. None will be built, according to the Tesla sales guy we talked to.

Color wars

The company also eliminated its green and brown paint color options, leaving only the staidly monochromatic black, white, silver, and grey, plus blue and red.

2012 Tesla Model S, brief test drive, New York City, July 2012

That lineup faithfully echoes the sadly predictable, traditional palette offered for decades upon decades by every German luxury-car brand.

As far as the brown goes....well, I won't make the obvious joke.

But I was personally sad to see the green disappear. That's the color I chose for my Model S, and I love it. A very dark British racing green, it sparkles magically in the sunshine.

So I'm wondering: how does eliminating a couple of colors speed up the production process?

I can understand Henry Ford's any-color-you-want-as-long-as-it's-black approach to the Model T production line.

2013 Tesla Model S electric sport sedan [photo by owner David Noland]

But once you start offering color options, does it really slow down the production line to have nine colors available instead of seven?

Tesla also eliminated the option for black roofs. Again, my Model S has the black roof, and I really like the look. But I understand how switching colors in the middle of the painting process can complicate things.

Oh, well. At least maybe my black-roofed green Model S, as a rare orphan, will have some extra resale value down the road.

Option shuffle

Tesla also winnowed down its interior options, eliminating the performance leather and Lacewood decor.

Parking sensors and fog lamps have now been integrated into the $4,250 tech package.

2014 Tesla Model S

And that tech package is now required to receive future software updates for the upcoming autopilot convenience features.

However, the safety features of the autopilot system, including lane-departure warning and blind-spot warning, will still be available on every Model S that has been equipped from the factory with the radar, and ultrasonic sensors for the autopilot system.

After this flurry of revisions to models and features, Tesla says there will be no major platform or hardware changes in the Model S for at least a year.

Damn. No 110-kWh battery? No two-door Model S coupe?

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