Is the blistering acceleration for Tesla’s P85D and P90D being slightly over billed?

Tesla says the Tesla P85D accelerates from 0-60 mph in 3.1 seconds, but Consumer Reports and Edmunds.com say under their careful testing, it turned 3.5 seconds.

Does that mean the P90D might also be over-estimated, and return 3.2, not 2.8 seconds?

That’s still unknown, but more is known about the P85D.

In the course of touting their own accuracy, Edmunds and CR suggest others may be less accurate than they are in getting the real numbers.

Acceleration runs can vary depending on factors including road conditions, and driver skills, though the P85D is user friendly to launch.

Both CR and Edmunds employ careful test conditions, use a VBOX for precise data collection, and have expert drivers.

From a dead standstill, on clean grippy pavement with no perceptible tire spinning or squealing, a video shows the P85D launched to 3.5 seconds.

Edmunds says the same in its 2015 P85D review.

“The 2015 Tesla Model S P85D does zero to 60 in 3.5 seconds and that might be the least interesting thing about it,” opens Edmunds.com’s review.

What conditions may have been different to suggest the P85D is 0.4 seconds slower than Tesla and other magazine testers say?

It is uncertain, but it may be that they did not employ a technique known as “rollout.” This is sort of like cooking the books to shave off a couple-few tenths of a second for those all-important 0-60 bragging rights.

As observed by readers at InsideEVs, Edmunds.com explains how it does not use rollout, calling it a “bogus practice,” and it would appear the same is true for CR.

A Few Words About Rollout The term “rollout” might not be familiar, but it comes from the drag strip. The arrangement of the timing beams for drag racing can be confusing, primarily because the 7-inch separation between the “pre-stage” and “stage” beams is not the source of rollout. The pre-stage beam, which has no effect on timing, is only there to help drivers creep up to the starting position. Rollout comes from the 1-foot separation (11.5 inches, actually) between the point where the leading edge of a front tire “rolls in” to the final staging beam — triggering the countdown to the green light that starts the race — and the point where the trailing edge of that tire “rolls out” of that same beam, the triggering event that starts the clock. A driver skilled at “shallow staging” can therefore get almost a free foot of untimed acceleration before the clock officially starts, effectively achieving a rolling-start velocity of 3-5 mph and shaving the 0.3 second it typically takes to cover that distance off his elapsed time (ET) in the process. We believe the use of rollout for quarter-mile timed runs is appropriate, as this test is designed to represent an optimum drag strip run that a car owner can replicate at a drag strip. In the spirit of consistency, we also follow NHRA practice when calculating quarter-mile trap speed at the end of the run. So we publish the average speed over the final 66 feet of the quarter-mile run, even though our VBOX can tell us the instantaneous speed at the end of the 1,320-foot course, which is usually faster. On the other hand, the use of rollout with 0-60 times is inappropriate in our view. For one, 0-60-mph acceleration is not a drag-racing convention. More important, it’s called ZERO to 60 mph, not 3 or 4 mph to 60 mph, which is what you get when you apply rollout. While it is tempting to use rollout in order to make 0-60 acceleration look more impressive by 0.3 second, thereby hyping both the car’s performance and the apparent skill of the test driver, we think it’s cheating. Nevertheless, some car magazines and some automobile manufacturers use rollout anyway — and fail to tell their customers. We’ve decided against this practice. We publish real 0-60 times instead. But in order to illuminate this issue and ensure we do justice to every car’s real performance, we’ve begun publishing a clearly marked “with rollout” 0-60 time alongside the primary no-rollout 0-60 time so readers can see the effects of this bogus practice.

Neither Edmunds.com nor Consumer Reports explicitly say Tesla employs rollout, and it may be that Tesla did not, and it did honestly turn a better time than either publication could muster.

Like Edmunds, Consumer Reports does boast of its painstaking accuracy in data measuring, and does observe its numbers – including for 87 MPGe, not the EPA’s 93 – do vary from official estimates.

CR bought its own P85D just like it does all its cars, and carefully analyzed it on its own test track under sophisticated laboratory-like conditions.

It also found the over 4,800-pound P85D to provide stellar slalom and braking scores suggesting this really is a sports car with four doors, and despite the hefty curb weight.

Both publications actually say the P85D is an amazing car in many respects, and do not focus on 0-60 times.

So do 0-60 times even matter? For many consumers’ personal sensibilities, the answer is No.

And, some will further observe, the P85D is already dominating conventional cars in many respects, and the P90D will be even quicker.

But acceleration does matter to others, and videos of owners racing it against Lamborghinis, Ferraris, BMW i8, and others have become quite the spectator sport.

Like any other score, the precise 0-60 number has also become a talking point, or badge of honor.

It all started with the after-hours g-force laden acceleration run Tesla hosted last October.

Following that event purpose-made to induce maximum sensory overload at night with bright lights in a tunnel, numerous media reported with articles and videos the amazing 0-60 time that was initially 3.2, then upgraded to 3.1.

The electric car that is quicker than many ultimate gas cars has in turn augmented already present interest in Tesla, and Michigan-based analyst Alan Baum observes increased public attention has bought time for Tesla as the Model X and Model 3 are delayed, but pending.

Existing owners have been turning in almost-new Teslas to trade up to the P85D and now P90D, and in a world where decisions are made on spec-sheet analysis, and other intangible or emotion-based factors, 0-60 in 3.5 seconds, not 3.1 may be relevant.

But as Edmunds also says, “that may be the least interesting thing” about the Model S P85D, which still puts many conventional cars to shame with zero emissions and all-electric drive.

It has also goaded other automakers to try and catch-up, and even elite Aston Martin’s CEO was reported this week reacting to the P90D’s “Ludicrous” mode.

So no matter what its 0-60 time, the Model S is disruptive, and remains in a class of one.

It is also paving the way for Model 3 which is to be revealed next year, be a volume seller, and enable those who don’t have as much to spend to still buy a Tesla.