2017 Tesla Model 3: Stopping Distance Retest After an ABS Firmware Update
by Dan Edmunds, Director of Vehicle Testing
We exam 60-0 mph panic stops given it’s an vicious reserve criteria. Cars that can stop in a shorter stretch are reduction expected to rear-end a automobile ahead. In cases where a pile-up is inevitable, they can drain off some-more speed before hit is made. Besides a brakes themselves, 3 criteria impact braking performance: a hold accessible from a tires, a aspect attrition and peculiarity of a road, and a inclination of a antilock stop complement (ABS).
Our initial 2017 Tesla Model 3 full-ABS panic-stop dimensions of 133 feet was indeed subsequent average. But it didn’t seem outrageous, generally given a characteristics of a customary 18-inch tires. They’re tough (with a treadwear rating of 500), they run during an abnormally high tire vigour (45 psi), and their 235 mm step breadth isn’t inexhaustible deliberation a car’s 3,884 pounds of weight. It all seemed to fit, though that was before Consumer Reports reported a 60-0 mph interlude stretch of 152 feet, scarcely 20 feet longer than ours.
Location is a categorical disproportion between a tests. Our Southern California lane is well-spoken and good cared for. Consumer Reports’ test lane is in Connecticut, where there’s genuine winter. It isn’t open to a public, though I’m devising it has a formally grippy aspect that is looked after. But with a certain volume of roughness and maybe even a few cracks brought about by a rigors of winter, CR’s has a unavoidable aspect irregularities we know a lane doesn’t have.
I didn’t think ABS calibration after a exam because, frankly, that’s tough to screw up. And a apparent reserve import concerned means that ABS calibrations are typically optimized to a nth grade before a automobile goes on sale. But ABS tuning though seemed some-more expected after Consumer Reports announced a shocking figures, generally deliberation my suspicions about a track. Tesla private any remaining doubt by announcing a approaching redeem of a new over-the-air firmware refurbish that it pronounced would residence a issue.
We recently reliable that a automobile was updated with chronicle 2018.18.13, a firmware chronicle that according to Tesla “improved a calibration of a antilock braking module to be some-more effective opposite variations in use and environmental conditions.” We took this as a vigilance to take a Model 3 behind to a exam track.
With this new firmware, CR saw a nearby 20-foot alleviation to 133 feet — a same stretch we totalled in a initial pre-fix testing. Tesla’s revised ABS calibration did indeed lead to shorter stops on a exam track, and a poignant bulk of a alleviation suggested that Tesla’s initial Model 3 ABS balance wasn’t really good.
Thing is, we know a exam lane is well-spoken and definitely giveaway of cracks. And given a initial formula were matching to CR‘s softened ones, we had no thought if we would see any alleviation on a home turf.
But we did.
Our initial stop with a revised firmware totalled 123 feet, accurately 10 feet shorter than a prior best. The second stop came in somewhat improved during 122 feet. In terms of feel, a initial “bite” of a brakes was some-more positive, and a ABS complement pulsing was smoother around a stop. Our Tesla Model 3’s interlude stretch is now right where we’d design it to be. Not improved or worse than average, though solidly midpack.
As acquire as this was, it was still tough to take. Our outcome tells us that Tesla missed a ABS calibration symbol in scarcely ideal conditions, not usually less-than-perfect ones.
In a lane exam video, we struggled with this and attempted to come adult with an swap explanation. we theorized that a handoff from regenerative to attrition braking competence be in play — a singular emanate that electric vehicles contingency understanding with. This probability seemed generally trustworthy in light of a Model 3’s rear-axle-only regenerative braking and rearward weight bias.
EVs try to redeem as most appetite as they can regulating regenerative braking, a intrigue wherein a electric expostulate engine is reconfigured to be a generator when a motorist wants to delayed down. Regenerative appetite liberation is something we wish to do as most of as probable to maximize range. During a panic stop, however, it’s best to switch it off and let a stop pads and rotors work alone with a ABS complement to govern a shortest stop possible.
This choice reason was apparently bunk. Tesla has given reached out to contend my handover speculation was not a issue. The carmaker put it all down to ABS calibration. I’d contend it was a quite bad ABS stop calibration if we could magnitude such a large disproportion on such a well-spoken surface.
The second biggest certain to come out of this was a palliate with that a automobile was updated. Over-the-air firmware updates usually happen, and Tesla is a usually automobile association that swears by them. Because of this, no outing to a use core was involved. We got told that an refurbish was about to start overnight around an on-screen message, and it was finished when we got in a automobile a subsequent morning. With any other company, this would have been a grave remember that could have dragged on by a extensive examination routine before a dealer-installed pill was finished available.
The usually difficulty with what is being called “the stop fix” is that it wasn’t described in a on-screen “Release Notes” that typically accompany vital updates. At initial we didn’t know if a automobile had been updated or not. It turns out that 2018.18.13 was indeed a one, though that download came with no reason or outline whatsoever. we perceived acknowledgment from Tesla open family after a fact.
If we possess a Model 3, your automobile has roughly positively been updated. Check your car’s program chronicle series to be sure. The “18” in a center of a series method refers to a 18th week of a year, and a 13 refers to a 13th program iteration of that week. Any method series that reads 18.13 or aloft means we are up-to-date.
This is a vicious update, though don’t design to notice any disproportion in daily driving. The ABS calibration usually comes into play during really tough puncture stops or when braking aggressively on scarcely uneven, unwashed or soppy surfaces. The categorical exception, of course, is wintertime pushing on sleet and ice, though we’re months divided from meaningful how that competence have changed.
It’s good that such a poignant problem fortitude was so simply finished with no bid on a part. But this should not have happened in a initial place. It’s kind of like examination a motorist get all laterally in a competition and afterwards miraculously keep it out of a wall. “Great save! What skill,” they’ll say. I’m a one who will reply, “Skill? Aren’t we forgetful that he botched a dilemma in a initial place?”
Dan Edmunds, executive of car contrast @ 6,437 miles