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Tesla Model S Drive Unit Replacement by the Numbers
During my early days of researching the Tesla Model S, I had concerns about a number of things that were emerging in the press. Fires, Model S drive unit issues, and handling in the snow. Tesla quickly addressed the “firegate” issue by retrofitting the Model S with a titanium shield. My concerns around winter driving, in particular handling in the snow, also became a non-issue after watching several winter driving videos put together by Bjørn Nyland.
Within no time, I became a new Model S owner and quickly learned that driving in the winter could actually be quite fun with a good set of winter tires. Tesla later introduced the all-wheel drive “D” models putting to rest any remaining doubt that the Model S could be the best and safest handling car in the world.
But one question still remains for me, Has Tesla dealt with the Drive Unit issues?
Model S Drive Unit Replacement by the Numbers
There is a group of Model S owners across the forums, but also validated by major publications such as Edmunds, that have had one or more drive unit replacements.
Early reports of drive unit issues ranged from total failures that left the Model S inoperable, to more recent complaints of clunking and milling noises. Elon has said in the past that many of these pre-emptive drive unit replacements were unnecessary and a simple $0.50 shim was all that was really needed, yet Tesla Service centers have been proactively replacing drive units.
The following polls from TMC show that a majority of Model S owners have had their drive units replaced.
While the poll only represents a small sample of Model S owners, one might draw significance in the numbers as the density circles around owners needing a drive unit replacement at relatively low mileage, and without any harsh driving prior to failure.
The polls also give insight to the motive behind each drive unit replacement.
Though it appears the issues mainly center around earlier versions of the Model S, there’s been reports of newer Model S with Autopilot hardware hearing milling noises coming from the drive unit. One viewer described the sound as “sawing wood”.
Tesla’s Response to Drive Unit Issues
In typical Tesla fashion, the company acted fast to address the issues, and curb concerns by offering an unlimited mile/8 year warranty on the drive unit. I think this was a great response by Tesla which put to rest any concerns about the quality and long term durability of their drive units.
Elon is now talking about building a power train that will last a million miles and I believe Tesla continues to put significant energy into improving the drive units. Tesla continues to honor the warranty and is proactively replacing drive units that show early signs of problems.
My Experience
After 12 months of Model S ownership and 30k miles drive, I started hearing a humming noise from the rear of my Model S during highway cruising. The noise was unusual as I had gotten used to hearing only the noise of the tires and wind, but there was a new noise only noticeable when cruising or decelerating with regeneration at 65 MPH and over. The noise continued to become more audible over the next few months, but I learned to live with it and did not contact Tesla. My personal rule of thumb on noise related issues is to wait for passengers to comment on it first. It’s my self crazy check.
Two months after the original drive unit humming noises began, a higher pitched milling type noise started occuring when traveling at speeds of 20 MPH or less. The sound varied depending on how much power was being used. That’s when I reached out to Tesla.

Tesla service record
Tesla service had me come in for a test drive which they can do on demand without you needing to wait. We drove about a block before the Tesla service technician said the drive unit needed to be replaced.
The explanation was that tolerances inside the drive unit have led to metal particles getting into the fluid around the drive unit, and as the concentration of particles increased, it caused the noise from the drive unit to become louder when under load. The new drive units evidently have better tolerances and are less prone to having metal particles being shaved off.
At that time, Tesla service has been very backed up here in Massachusetts so my appointment for the drive unit replacement was scheduled six weeks out. I put on another 4,000 miles during that wait time, with an increasingly louder drive unit, before it was finally replaced.
When Tesla replaces a drive unit, they replace both the drive unit and inverter as you can see from a copy of the parts list. The last letter in the drive unit part number (“M” in my case) seems to indicate the generation of the drive unit. The later the letter the better, with the “Q”s seeming to have the best longevity according to the forums.
I’m happy to say that I’ve logged 8,000 miles of happy and noise-free driving after my drive unit replacement. The replacement was done recently so my guess is that I have a newer unit, and thus hope this will be my only replacement.
Thankfully for all of us, Tesla has a first class warranty and level of service. While it goes without saying that inconveniences such as this may happen, rest assured that Tesla has you covered and will always strive to make things right.
News
Tesla Full Self-Driving shows confident navigation in heavy snow
So far, from what we’ve seen, snow has not been a huge issue for the most recent Full Self-Driving release. It seems to be acting confidently and handling even snow-covered roads with relative ease.
Tesla Full Self-Driving is getting its first taste of Winter weather for late 2025, as snow is starting to fall all across the United States.
The suite has been vastly improved after Tesla released v14 to many owners with capable hardware, and driving performance, along with overall behavior, has really been something to admire. This is by far the best version of FSD Tesla has ever released, and although there are a handful of regressions with each subsequent release, they are usually cleared up within a week or two.
Tesla is releasing a modified version of FSD v14 for Hardware 3 owners: here’s when
However, adverse weather conditions are something that Tesla will have to confront, as heavy rain, snow, and other interesting situations are bound to occur. In order for the vehicles to be fully autonomous, they will have to go through these scenarios safely and accurately.
One big issue I’ve had, especially in heavy rain, is that the camera vision might be obstructed, which will display messages that certain features’ performance might be degraded.
So far, from what we’ve seen, snow has not been a huge issue for the most recent Full Self-Driving release. It seems to be acting confidently and handling even snow-covered roads with relative ease:
FSD 14.1.4 snow storm Ontario Canada pic.twitter.com/jwK1dLYT0w
— Everything AI (@mrteslaspace) November 17, 2025
I found the steepest, unplowed hill in my area and tested the following:
• FSD 14.2.1 on summer tires
• FSD 14.2.1 on winter tires
• Manual drivingBut I think the most impressive part was how FSD went DOWN the hill. FSD in the snow is sublime $TSLA pic.twitter.com/YMcN7Br3PU
— Dillon Loomis (@DillonLoomis) December 2, 2025
Well.. I couldn’t let the boys have all the fun!
Threw the GoPro up and decided to FSD v14.2.1 in the snow. Roads were not compacted like the other day, a little slippery, but overall doable at lower speeds. Enjoy the video and holiday music 🎶
Liked:
Took turns super slow… pic.twitter.com/rIAIeh3Zu3— 🦋Diana🦋 (@99_Colorado) December 3, 2025
Moving into the winter months, it will be very interesting to see how FSD handles even more concerning conditions, especially with black ice, freezing rain and snow mix, and other things that happen during colder conditions.
We are excited to test it ourselves, but I am waiting for heavy snowfall to make it to Pennsylvania so I can truly push it to the limit.
News
Tesla hosts Rome Mayor for first Italian FSD Supervised road demo
The event marked the first time an Italian mayor tested the advanced driver-assistance system in person in Rome’s urban streets.
Tesla definitely seems to be actively engaging European officials on FSD’s capabilities, with the company hosting Rome Mayor Roberto Gualtieri and Mobility Assessor Eugenio Patanè for a hands-on road demonstration.
The event marked the first time an Italian mayor tested the advanced driver-assistance system in person in Rome’s urban streets. This comes amid Tesla’s push for FSD’s EU regulatory approvals in the coming year.
Rome officials experience FSD Supervised
Tesla conducted the demo using a Model 3 equipped with Full Self-Driving (Supervised), tackling typical Roman traffic including complex intersections, roundabouts, pedestrian crossings and mixed users like cars, bikes and scooters.
The system showcased AI-based assisted driving, prioritizing safety while maintaining flow. FSD also handled overtakes and lane decisions, though with constant driver supervision.
Investor Andrea Stroppa detailed the event on X, noting the system’s potential to reduce severe collision risks by up to seven times compared to traditional driving, based on Tesla’s data from billions of global fleet miles. The session highlighted FSD’s role as an assistance tool in its Supervised form, not a replacement, with the driver fully responsible at all times.
Path to European rollout
Tesla has logged over 1 million kilometers of testing across 17 European countries, including Italy, to refine FSD for local conditions. The fact that Rome officials personally tested FSD Supervised bodes well for the program’s approval, as it suggests that key individuals are closely watching Tesla’s efforts and innovations.
Assessor Patanè also highlighted the administration’s interest in technologies that boost road safety and urban travel quality, viewing them as aids for both private and public transport while respecting rules.
Replies on X urged involving Italy’s Transport Ministry to speed approvals, with one user noting, “Great idea to involve the mayor! It would be necessary to involve components of the Ministry of Transport and the government as soon as possible: it’s they who can accelerate the approval of FSD in Italy.”
News
Tesla FSD (Supervised) blows away French journalist after test ride
Cadot described FSD as “mind-blowing,” both for the safety of the vehicle’s driving and the “humanity” of its driving behaviors.
Tesla’s Full Self-Driving (Supervised) seems to be making waves in Europe, with French tech journalist Julien Cadot recently sharing a positive first-hand experience from a supervised test drive in France.
Cadot, who tested the system for Numerama after eight years of anticipation since early Autopilot trials, described FSD as “mind-blowing,” both for the safety of the vehicle’s driving and the “humanity” of its driving behaviors.
Julien Cadot’s FSD test in France
Cadot announced his upcoming test on X, writing in French: “I’m going to test Tesla’s FSD for Numerama in France. 8 years I’ve been waiting to relive the sensations of our very first contact with the unbridled Autopilot of the 2016s.” He followed up shortly after with an initial reaction, writing: “I don’t want to spoil too much because as media we were allowed to film everything and I have a huge video coming… But: it’s mind-blowing! Both for safety and for the ‘humanity’ of the choices.”
His later posts detailed FSD’s specific maneuvers that he found particularly compelling. These include the vehicle safely overtaking a delivery truck by inches, something Cadot said he personally would avoid to protect his rims, but FSD handled flawlessly. He also praised FSD’s cyclist overtakes, as the system always maintained the required 1.5-meter distance by encroaching on the opposite lane when clear. Ultimately, Cadot noted FSD’s decision-making prioritized safety and advancement, which is pretty remarkable.
FSD’s ‘human’ edge over Autopilot
When asked if FSD felt light-years ahead of standard Autopilot, Cadot replied: “It’s incomparable, it’s not the same language.” He elaborated on scenarios like bypassing a parked delivery truck across a solid white line, where FSD assessed safety and proceeded just as a human driver might, rather than halting indefinitely. This “humanity” impressed Cadot the most, as it allowed FSD to fluidly navigate real-world chaos like urban Paris traffic.
Tesla is currently hard at work pushing for the rollout of FSD to several European countries. Recent reports have revealed that Tesla has received approval to operate 19 FSD test vehicles on Spain’s roads, though this number could increase as the program develops. As per the Dirección General de Tráfico (DGT), Tesla would be able to operate its FSD fleet on any national route across Spain. Recent job openings also hint at Tesla starting FSD tests in Austria. Apart from this, the company is also holding FSD demonstrations in Germany, France, and Italy.


