Understanding the Tesla Model S Performance Motor

Join me for a deep dive into the details of the 18,000 RPM performance rear motor and drive unit from a 2015-2016 Tesla Model S P90D. This drive unit is similar to the one used in the 2017-2020 P100D. The video is divided into four sections showing: 1. The motor and gears. 2. The high-performance bearings. 3. The lubrication system. and 4. The cooling system.

Thank you to everyone for catching my errors. There are always errors ;)
1. The Nissan Leaf ring gear is held on with 8 bolts, not 6.
2. The fluid in this drive unit is Dexron 6 transmission fluid.
3. Induction motor rotors do not have poles, just the stator. The 60 slot stator has four poles.
4. Silicon Nitride is a ceramic material.

0:00 Start
0:10 Introduction
1:35 Gearbox housing
2:10 Video Section 1 - Gears and Motor Rotor
2:45 The giant differential ring gear with 16-bolts!
4:20 The giant differential case bearings
4:50 The differential case speed at 250 km/h (155 mph) = 1841 RPM
5:15 MUST SEE Comparing the Tesla 213mm x 50mm. ring gear with 78 teeth (Factors 2, 3, 13) to a Chevrolet Bolt EV and Nissan Leaf EV
5:40 A Chevrolet Bolt EV differential 198mm x 34.3mm ring gear with 12-bolts.
6:10 A Nissan Leaf EV differential 200mm x 32mm ring gear with 8-bolts!
7:30 The Counter Shaft (Jack Shaft) with 25 (Factors 5, 5) pinion gear teeth. 78/25 = 3.12:1 Gear ratio from countershaft to the differential case
8:50 The countershaft speed at 250 km/h (155 mph) = 5743 RPM
9:30 The motor shaft with 25 teeth drives 78 teeth on the countershaft for another gear reduction of 78/25 = 3.12:1
10:08 The motor shaft speed at 250 km/h (155 mph) = 17,919 RPM
11:20 See all three gears in the reduction gearbox with an overall gear reduction of (78/25) x (78/25) = 9.7344:1
12:05 MUST SEE The AC Induction Motor Rotor with 74 bars
13:25 Motor specifications for power, torque, and gear ratio
15:00 MUST SEE Ceramic Bearings (Silicon Nitride) on the rotor from the SKF Group (skf.com)
16:22 MUST SEE Close up view of silicon nitride bearing
18:20 The motor rotor speed sensor reluctor wheel (tone ring)
19:22 Must SEE The rotor installed on the drive gear and the functioning gearbox
20:18 Video Section 2 - Specialized Bearings
21:21 The 60 slot four-pole stator and housing
23:05 The oil pump and how it is overdriven by the differential ring gear 23/78 = 0.2948:1 gear ratio (3.339 times faster than the ring gear)
23:55 MUST SEE The function of the oil pump (it may surprise you)
26:27 Motor shaft (Input Shaft) bearing reference speed and limiting speeds
27:30 How to run bearings at higher speeds than their limiting speeds
29:54 Video Section 3 - Lubrication
30:25 Drain and fill plug locations
30:50 Gearbox vent and inverter vents
31:05 Sport model label
31:39 MUST SEE Four different sealed areas in the drive unit
32:46 Video Section 4 - Cooling System
33:30 MUST SEE The coolant inlet port and the two paths coolant takes
33:53 Up for rotor cooling and gearbox cooling
35:03 Down for stator and inverter cooling
36:05 Coolant from the rotor moves to the gearbox heat exchanger and the outlet port
37:25 Stator temperature sensors
38:10 Coolant from the stator to the inverter coolant passages
38:28 Stator coolant temperature sensor
38:35 MUST SEE Insulated-Gate Bi-Polar Transistor (IGBT) module coolant passages and flow through gearbox passages
40:34 Inverter coolant outlet temperature sensor
40:45 The gearbox oil-to-coolant heat exchanger
41:38 Coolant outlet port to coolant pump and onboard charger module under the back seat.
41:55 Drive unit cooling system summary
43:04 IGBT inverter modules installed and inverter cover
43:40 High voltage battery cable connections and low voltage connections at the inverter
44:35 Video summary

Weber State University (WSU) Davis Campus - Automotive Technology Department - Advanced Vehicles Lab. A technical description and demonstration of the Tesla P90D Rear Drive Unit (RDU). We teach current vehicle technologies to our automotive students at Weber State University and online. For more information visit: www.weber.edu/automotive

This video was created and edited by Professor John D. Kelly at WSU. For a full biography, see www.weber.edu/automotive/J_Kel...

Visit my other youtube channel www.youtube.com/user/vibrates... to see the amazing NVH app for vibration diagnosis!

Join us for hybrid and electric vehicle training with two online courses and in a 5-day on-campus boot camp with Professor John D. Kelly. See www.weber.edu/evtraining

Please consider a donation to the Department of Automotive Technology at Weber State University here: advancement.weber.edu/Automotive


  • Umit Battal
    Umit BattalDag sedan

    Is that motor producing 500 hp or is it due to gearing hp on wheels?

  • Brian Banks
    Brian BanksDag sedan

    nice presentation.....looks scary until you take it apart...then it all comes into focus perfectly

  • Nándor Udvarhelyi
    Nándor UdvarhelyiDag sedan


  • mohd zaki mamat
    mohd zaki mamatDag sedan

    very impresive explanation on tesla motor.... good to know about the engine..

  • Jacks Parro
    Jacks Parro2 dagar sedan

    Balls of ceramic have put balls of steel to shame.

  • Kai Kniivilä
    Kai Kniivilä2 dagar sedan

    Very intresting video and very good represented. I think I understood big part of this. Thank You Very much for this.

    MR BACKHAND3 dagar sedan

    Im about to buy a Lamborghini Countach Replica..... I would Love to put that Setup in my car.... where do i buy the units?

  • Soniti1324
    Soniti13244 dagar sedan

    This was an incredible video. I finally found an analysis of how these motors work that will satisfy my father in law!

  • Gerald Abele
    Gerald Abele4 dagar sedan

    To simplify your excellent work, try dry ice blasting to clean all these parts - works wonders in a fraction of time.

  • bla bla bla bla
    bla bla bla bla6 dagar sedan

    Thank you sir. I learn a lot.

  • عبدالعظيم عمر
    عبدالعظيم عمر6 dagar sedan

    Great video thank you professor

  • Taylor Langley
    Taylor Langley6 dagar sedan

    Great video! I like how you did your research and pulled the sources from the manufacturer.

  • skigdivider x
    skigdivider x6 dagar sedan

    8 bolts on the Nissan junk.

  • Paul Burtea
    Paul Burtea7 dagar sedan

    You have the gift to explain and to simplify

  • Paul Burtea
    Paul Burtea7 dagar sedan


  • carlu bambi
    carlu bambi7 dagar sedan

    I'm a master electrician, I have seen many ac motors and DC motors with massive bearings, they are hooked up to drives because the ammout of torque the motors can generate on start up is insane, equipment can be destroyed if they are started across the line. Electric motors can be smaller but have massive amount of torque and power for their size

  • Santiago Castro
    Santiago Castro7 dagar sedan

    22:00 it is heavy but it produces 500 HP!!

  • Wesley LeBaron
    Wesley LeBaron8 dagar sedan

    When I worked at gigafactory 1 in the stator debt i the pm stators are 6 loop 3 poles and each stator has over 1.2 miles of coated copper wire, also the stator housing is heated up and the stator is pressed in so as the housing cools down it cold welds to the stator the do the same thing with I'm PM rotors but its chilled to sub-0 temps using liquid nitrogen the a 6 DOF 6-axis fantic robot arm spins the rotor until the rotor is above 0° C (32°F). Also the oil is just standerd automatic transmission fluid.

  • D.A.L.
    D.A.L.9 dagar sedan

    I wish I could afford a used tesla drive unit and everything needed to make it work. I'm planning to build my own car and it would be awesome to have it electric. But I'm just a poor working man so I guess I'm gonna have to stick with a gasoline powertrain

  • Timothy Maggenti
    Timothy Maggenti9 dagar sedan

    Nice Job, great job explaining everything. I really appreciate it.

  • Stephen Lambrecht
    Stephen Lambrecht9 dagar sedan

    Thanks to you, Prof John, I am happy to have purchased a Bolt EV. Transportation Evolved gave you a great thumbs up for your excellent work. I 2nd that and love my car.

  • eric olivo martinez
    eric olivo martinez9 dagar sedan

    Estos autos de tesla están muy bien construido ojalá y fabriquen autos económico que este al alcance de nosotros los pobres

  • eric olivo martinez
    eric olivo martinez9 dagar sedan

    Ojalá y los fabricante de vehículos eléctricos no sean todos igual que tesla que los autos solo están alcance de los ricos en usa en cambio en China se fabrican súper barato para que cualquier trabajador o persona del pueblo lo adquiera

  • Stan Rodgers
    Stan Rodgers10 dagar sedan

    8 bolts Nissan Leaf at 6 minutes.

  • Nizel D souza
    Nizel D souza10 dagar sedan

    great video mate!! informative

  • sam min
    sam min11 dagar sedan


  • Below asmelash habel shutel Gebremaraim
    Below asmelash habel shutel Gebremaraim12 dagar sedan


  • Below asmelash habel shutel Gebremaraim
    Below asmelash habel shutel Gebremaraim12 dagar sedan


  • David Elliott
    David Elliott12 dagar sedan

    I wonder why they don’t use two smaller motors and delete the differential. Also, epicyclic gears handle high torque and run quiet with straight-cut gears.

  • froop
    froop12 dagar sedan

    11:00 thats cool... but driving 250Km/h is no problem in Germany on the Autobahn 😁

  • Semih Fatih Adem
    Semih Fatih Adem13 dagar sedan

    Omg we are so lucky to hear these from a professor instead of a youtuber. Thanks for quality content

  • Horseman Oz
    Horseman Oz13 dagar sedan

    Excellent, thank you.

  • Abbas E1000
    Abbas E100014 dagar sedan

    This is just nonsense!!! All these electronic parts, in addition to the high speed of the electric motor, make it completely unsafe and vulnerable to electrical and mechanical faults, because the tension is doubled to almost ten times. This car is short-lived and has many faults, believe me.

  • LeZturbo
    LeZturbo15 dagar sedan

    Love the way you are describing/explaining things. I also loved the RAV4 hybrid trans explanation as I always said to my friends « there’s no real gearbox in a Prius, that’s the genius of it » !!!!

  • Kamil Fikret Alsancak
    Kamil Fikret Alsancak16 dagar sedan

    45 POLES 22:00

  • Alberto Martos del Rincón
    Alberto Martos del Rincón18 dagar sedan

    Congratulations! Very good training video!!!

  • Glen Orrett
    Glen Orrett18 dagar sedan

    this is very excellent, I watched this video knowing nothing about the drive unit for tesla and now I feel that I could confidently explain how things work

  • Jimmy Jawbone
    Jimmy Jawbone19 dagar sedan

    Very informative

    JORGE GUERRERO20 dagar sedan

    non conductive ball bearings, my favorite part

  • Rampal Grih Dhwaj Singh
    Rampal Grih Dhwaj Singh20 dagar sedan

    nice simply explained video

  • danny B
    danny B20 dagar sedan

    if your bored and disected the known universe can you take a part a renault zoe

  • danny B
    danny B20 dagar sedan

    thanks for the facts and not the anecdotes

  • danny B
    danny B20 dagar sedan

    dude you are 100 times more interesting than sandy keep it real

  • JerryMetal
    JerryMetal22 dagar sedan

    Elon built this engine in a cave with only a box of scraps!

  • Hasan Nasaji
    Hasan Nasaji23 dagar sedan

    you are best teacher

  • Good Will
    Good Will24 dagar sedan

    Absolutely amazing super job!!! Thanks

  • Steven Young
    Steven Young24 dagar sedan

    Outstanding and highly informative! Thank you👍

  • pbertf24
    pbertf2424 dagar sedan

    Simple and elegant..that is Tesla for u

  • Blacknass
    Blacknass27 dagar sedan

    warum hat Elon Musk den Namen Von Nicola Tesla geklaut ? um sein Produkt besser verkaufen lässt. Nicola Tesla dreht sich gerade ihm Grabe um ! Ich hoffe die Menschen werden erwachen und Elon zum teufel jagen !

  • DaChester
    DaChester27 dagar sedan

    min.6:10 Nissan Leaf 8 Bolts not 6

  • Carsten Biehl
    Carsten Biehl28 dagar sedan

    Aren't there 8 Bolts on the Leaf Differential?

  • Eugene Anderson
    Eugene Anderson28 dagar sedan

    Tiny for a Cat guy technology has been around since the 30’s

  • Jason Jones
    Jason JonesMånad sedan

    great video WeberAuto

  • DrHaiFisch
    DrHaiFischMånad sedan

    My Yamaha FS was spinning 18.000 rpm but just on 120 km/t...

  • Raghu Vamsi Kodaboina
    Raghu Vamsi KodaboinaMånad sedan

    That was one hell of a cooling system design. It is excellent. Thank you professor for such a wonderful presentation and explanation.

  • GeneHG
    GeneHGMånad sedan

    I was surprised that you didn't use a bead blasting technique to clean up the smoke residue. Different bead materials are available to give different aggressiveness. Glass beads work great for rusty things. The problem may be in finding a bead material that cleans smoke, but leaves printing and labels. Those could be masked off for manual cleaning.

  • WeberAuto


    Månad sedan

    It was too large and too heavy to put into our blaster. Thanks for watching

  • Dead Pilot
    Dead PilotMånad sedan

    I think that any oils for turbojet engines are suitable, there are the same "ceramic" bearings, rotations and loads.

  • DC9848
    DC9848Månad sedan

    Fantastic walk through for any Tesla fan, thanks for sharing!

  • tony bryan
    tony bryanMånad sedan

    Thank you sir for a most informative, detailed description of the Tesla motor and drive train. A really fascinating dive into the inner workings. I especially appreciate your candidness on what is not known for sure, Thank you, my friend.

  • unknown unknown
    unknown unknownMånad sedan

    legal factors and the fact that probably 70% of the masses will never drive 155 for at all let alone any length of time is why we as a populace need to get away from buying cars over powered to do greater than legal speeds. it will make electric cars more effective and more efficient and kill the need for a massive recharge network that some company is willing to make as long as they can monetarily rape us for it. same would happen if gas cars were made super efficient from the start, but people needed cars to go long distances quickly, gas companies wanted to sell a product that is instantly lost through use and needed you to buy more $$$$$ and failing of parts meant to fail through use $$$$$since ev's have much fewer parts that's much less $$$$ over time for car companies so dont plan on them making them more efficient and just trying to sell you the research time it takes to make little changes in battery tech and charging stations and high price of entry for a ev. Also until people the populace grows up and demand power efficient non over powered people movers the car companies and developers will always lube up and wait for you to knock on their door.

  • tariq ruwaili
    tariq ruwailiMånad sedan

    can't wait for the plaid motor

  • Алексей Михайленко
    Алексей МихайленкоMånad sedan

    Дядька шарит, и произношение очень четкое, можно и про устройство узнать и Английский подучить)

  • TecSanento
    TecSanentoMånad sedan

    "most people will never experience these speeds" ... me laughing in german (drovve a 90D on german autobahn at 250km/h for about half an our :D)

  • tony bryan

    tony bryan

    Månad sedan

    Too much fun ;

    MARK MALASICSMånad sedan

    6:15 No, it doesn't have 6 bolts, it has 8 bolts.

  • No-one_no1
    No-one_no1Månad sedan

    6 bolts on the leaf you say?

  • apouy gaming
    apouy gamingMånad sedan

    good video

  • Andrew M
    Andrew MMånad sedan

    Doesn't that Nissan Leaf have eight bolts holding the ring gear in?

  • Jules CAIRON
    Jules CAIRONMånad sedan

    Amazing work from this professor. Thanks a lot.

  • cookiehead2
    cookiehead2Månad sedan

    Dextron VI is used in a lot of things

  • SquillyMon
    SquillyMonMånad sedan

    An Absolute Master Class Discussion right here

  • SquillyMon
    SquillyMonMånad sedan

    So what you're saying is... DO-NOT physically damage that housing! Holy Smokes I had no clue of the level of simplicity and complexity going on in that assembly. I suspected as much but this blew my mind. Some adventurous engineering right there!!

  • Donnie Dye
    Donnie DyeMånad sedan

    Really enjoyed the video. It's like showing a magicians tricks.

  • maria cornwallis
    maria cornwallisMånad sedan

    I have just orderd a hydrogen powered Toyota Mirai. BUGGER your EVs

  • Eric Schickelgruber aus Linz
    Eric Schickelgruber aus LinzMånad sedan

    Da gibt's kein Geheimnis. Patent ist 120 Jahre alt. Und funktioniert immer noch. Ist aber inzwischen technologisch Out of Date und alles andere als ein Performancemotor. Das Patnet ist sogar inzwischen Lizenzfrei. Darum nennt es Tesla auch Open Source. Ist ein Marketingtrick.

  • Ramiro Rodriguez
    Ramiro RodriguezMånad sedan

    Wow! Thank you so very much.

  • Stel ThirdEyeProductions
    Stel ThirdEyeProductionsMånad sedan

    Amazing! So much high tech in such a 'simple' design, driving components to extreme conditions. Such a 'well' balanced system. Looking forward to watch the power electronics video tonight. Brilliant explanation (as usual). A 'perfect in every way' lecture! Respect!

  • Someoneelse
    SomeoneelseMånad sedan

    Did someone get a labelmaker for christmas?

  • tony bryan

    tony bryan

    Månad sedan

    He's a teacher. Teachers are gonna teach. ;

  • thewitchertales
    thewitchertalesMånad sedan

    what a great educational and well made video with tons of detail... great job man!

  • thewitchertales
    thewitchertalesMånad sedan

    35:00 it passes threw the stator housing and middle of stator not only to cool but it can run the induction rotor without the car moving to build up heat so the heated coolant and warm up the battery if its cold. pretty genious.

  • Jim Mcfarland
    Jim McfarlandMånad sedan

    OMG another Elon Musk fanboy....

  • Mauricio Ocampo
    Mauricio OcampoMånad sedan

    Great video.

  • ryusuke yamamoto
    ryusuke yamamotoMånad sedan

    This is best automotive channel . Thank you for all this information open to public 😃amazing

  • Kei Davis
    Kei DavisMånad sedan

    The Nissan Leaf you showed has 8 bolts, not 6.

  • gentel fix
    gentel fixMånad sedan

    Really inpirational

  • Steven Madsen
    Steven MadsenMånad sedan

    Can you suggest a good e-bike Tesla motor??

  • vinda narine
    vinda narineMånad sedan

    Excellent video, are you a teacher at a automotive school

  • StrawberryredfiestaST
    StrawberryredfiestaSTMånad sedan

    6:18 its 8 bolts not 6

  • StrawberryredfiestaST


    Månad sedan

    @WeberAuto you probably did hear this a lot already. sorry 😅. great video tho 👍🏼

  • WeberAuto


    Månad sedan

    Yes, I was wrong. Thanks for watching

  • akfinner1
    akfinner1Månad sedan

    This man really loves his bearings

  • WeberAuto


    Månad sedan

    LOL, yes. Thanks for watching

  • Creative1615
    Creative1615Månad sedan

    Excellent and educational video. Next should be The Rimac Concept One, direct drive motors for each wheel are their also gear boxes for each wheel?

  • WeberAuto


    Månad sedan

    That would be cool! No, direct drive

  • Krusty Pickles Gaming
    Krusty Pickles GamingMånad sedan

    ive heard they use bmw coolant to cool their batteries. maybe they use bmw spec oil for the drive unit

  • WeberAuto


    Månad sedan

    I do not know. Thanks for watching

  • rishabh sehgal
    rishabh sehgalMånad sedan

    Dislikes for?

  • tony bryan

    tony bryan

    Månad sedan

    @sam smith The prof didn't diss anything or anyone. He just explained stuff. And he did an excellent job, in my opinion. :

  • sam smith

    sam smith

    Månad sedan

    Tesla fan bois think elon touches anything and it turns to gold, down vote from Tesla haters. Tesla fan bois down vote any video that diss Tesla. You gonna get down votes whichever way you do the video. Best not get involved in any Tesla argument if you dont want down votes.

  • WeberAuto


    Månad sedan

    I gave up trying to figure that out. Thanks for watching

  • turbyturbo1
    turbyturbo1Månad sedan

    can you do the plaid ?

  • WeberAuto


    Månad sedan

    I hope so! someday

  • Tuğrul Tamer Coşkun
    Tuğrul Tamer CoşkunMånad sedan

    awesome video! thank you!

  • Runforestrun FPV
    Runforestrun FPVMånad sedan

    Mechanically it is similar to a transmission unit of my team associated SC10 without the need for extensive liquid cooling unit.

  • neil barron
    neil barronMånad sedan

    I would like to "guess-to-mate" that all the cooling on the electrics is more to transfer the heat to inside of the cabin. After all how else would could one heat the interior? Any one thats owned VW bug knows about this issue on a cold Canadian January morning!! I am quite sure other high power electric motors are air cooled such as an elevators and such that get as hot or even hotter. I would really like to know at what temp the engineers designed this whole unit to operate at. And thank for a great break down and video!!

  • tkswdr
    tkswdrMånad sedan

    The non burned engine has a sticker saying 18.5k if I'm right. That means 18500rpm limit.. ceramic bearings?

  • Jonas L
    Jonas LMånad sedan

    Great videos! Thanks for your effort! Will there be some videos about the Mustang Mach-E e-Drive? Especially the cooling would be interesting.

  • Devon Nobles
    Devon NoblesMånad sedan

    Did I miss something, or is that really 8 bolts on the leaf diff?

  • Euro Asia BT Limited
    Euro Asia BT LimitedMånad sedan

    Great video

  • Axel Werner
    Axel WernerMånad sedan

    i am surprised. i was expecting 4 wheel hub motors, not a single motor with lots n lots of gears.