Tesla Motors has built a strong reputation for performance, starting with its first Roadster and then its Model S P85 and P85+ sedans, before moving to the dual-motor P85D and most recently the latest line-leading P90DL.

But how much has performance actually improved with these evolutionary changes in the Model S, from single to dual motors and then on to a larger battery, better fusing and cables, and the stated potential of a quarter-mile time below 11 seconds?

On October 28, we got all three top-tier Tesla Model Ses at the same drag strip to compare the hard numbers.

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The weather was cool, the winds non-existent, and soon we would learn the truth: What were the actual quarter-mile times for each variant?

The benchmark was to be the P85D which took on the P85+ on the first paring of the evening.

The timing for each car after their quarter-mile runs told the story.

2015 Tesla Model S P85D - 'Chiseled by man and nature' [photo: George Parrott]

2015 Tesla Model S P85D - 'Chiseled by man and nature' [photo: George Parrott]

                             P85 +               P85D

60 ft                     2.12 sec.        1.66 sec.

330 ft                   5.55 sec         4.75 sec.

660 ft                   8.33 sec         7.39 sec

   mph                 87.19               92.43

1000 ft                10.76 sec       9.69 sec

1320 ft                12.83 sec.     11.65 sec

mph                    108.93           113.66

ALSO SEE: Drag-Racing My Tesla P85D: 71-Year-Old Novice Hits The Strip (Video)

Translated, that means the dual-motor P85D is more than a second faster to the final timing line than the older P85+, and almost 5 mph quicker at that point.

Frankly, that wasn't all that big a surprise. The bigger question was: What's the difference between the deposed monarch, the P85D, and the new king, the P90DL? (The "L" is shorthand to indicate that the car is running in its Ludicrous mode.)

It's an especially germane question because some P90D test drivers and owners have noted in various forums that the P90D doesn't necessarily produce the acceleration promised by Tesla.

2015 Tesla Model S P85D vs Mercedes-Benz S63 AMG at drag strip [photo: George Parrott]

2015 Tesla Model S P85D vs Mercedes-Benz S63 AMG at drag strip [photo: George Parrott]

                         P85D                P90DL

60 ft                 1.69 sec.            1.68 sec.

330 ft               4.80 sec.            4.68 sec.

660 ft               7.43 sec.           7.24 sec.

   mph             91.86                 95.35

1000 ft             9.74 sec.           9.48 sec.

1320 ft            11.70 sec.         11.40 sec.

  mph               114.23               115.17    

At the end of the run, in other words, the P90DL was 0.3 seconds faster through the quarter mile, but with a final speed less than 1 mph higher.

MORE: Tesla P85D Destroys Dodge Challenger Hellcat On Dragstrip: Electric Car Thrashes 707-HP Hemi (Video):

A second pairing of the P85D and the P90DL produced a similar delta: 0.32 seconds and about 2 mph. So clearly the P90DL topped the P85D both times.

But, this is the first time in our experience that a Tesla car has NOT made the performance numbers that the company so proudly posts: “quarter-mile time of 10.9 seconds…”.

McLaren 650S vs. Tesla Model S P85D

McLaren 650S vs. Tesla Model S P85D

In drag-racing terms, consistent quarter-mile times of 11.40 seconds are really light-years from the claimed 10.9 seconds--and for that small bump, the buyer pays $13,000 more than the P85D version.

We suspect there had better be a big firmware upgrade soon that gives P90DL owners what they thought they paid for.

CHECK OUT: Tesla Model S P85D 'Insane' Mode: NSFW Video Shows How Fast It Really Is:

Otherwise, Tesla could have more trouble on its hands than a slightly bruising long-term reliability rating from Consumer Reports.

[Our thanks to Danilo Crudele for providing video of this event.]


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