Understanding the Tesla Model S Front Motor

Join me for another deep dive to see the details of the 17,500 RPM front motor and drive unit from a 2014-2018 Tesla Model S AWD. See all four motor rotors from the Tesla Model S and Model 3. 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 electrical system.
TIMELINE:
0:00 Start
0:11 Model S, X, and 3 electric motor combinations
1:30 RWD Model S and X motors
1:37 AWD Model S and X motors
1:54 Performance AWD Model S and X motors
2:28 RWD and AWD Model 3 motors
3:10 MUST SEE Close up photos of all four motors
3:44 Video Section 1 - Gears and Rotor
3:56 Gear housing components
4:49 Comparison of differential with a rear performance motor
5:53 MUST SEE Why are the bearings and gears so big?
7:36 The front differential case speed at 250 km/h (155 mph) = 1877 RPM
7:54 MUST SEE Different tire sizes and different gear ratios
9:00 Installation of the front differential case with a 79 tooth ring gear (Prime Number)
9:22 The Counter Shaft with 21 (Factors 3, 7) pinion gear teeth. 79/21 = 3.7619:1 Gear ratio from countershaft to the differential case
10:41 The countershaft speed at 250 km/h (155 mph) = 7063 RPM
11:08 The motor rotor shaft and drive gear with 31 teeth (Prime Number)
11:35 MUST SEE Comparison of the front rotor to the rear performance rotor
12:56 Maximum torque at a vehicle speed comparison
15:36 Motor rotor speed sensor and reluctor wheel
16:15 Special high-speed deep groove rotor bearings from the SKF Group (skf.com)
16:49 MUST SEE SKF Ceramic Bearing (Silicon Nitride) on the rotor
17:43 The rotor is in a wet environment and cooled by the transmission fluid
18:33 MUST SEE Rotor shaft grounding rings with conductive filaments from (AEGIS?)
19:37 Shaft grounding protects bearings from damage from electrical current
20:10 The Rotor Shaft with 31 gear teeth drives the 77 (Factors 7, 11) tooth counter gear. 77/31 = 2.4839:1 Gear ratio.
20:52 See all three gears in the reduction gearbox with an overall gear reduction of (79/21) x (77/31) = 9.3441:1
21:26 The differential and the axle half shaft and jackshaft to reduce torque steer
22:23 Video Section 2 - Specialized Bearings
22:58 How Tesla run bearings at higher speeds than their limiting speeds with lubrication
23:07 Video Section 3 - Specialized Lubrication for bearings
23:34 The 20 tooth oil pump gear is overdriven by the differential ring gear 20/79 = 0.2531:1 gear ratio (3.95 times faster than the ring gear)
24:18 The transmission fluid drain and fill plugs
24:39 The fluid refill procedure
25:45 MUST SEE The proper fluids for the front-drive unit (Mobile SHC 629 and Dexron VI)
28:00 The path of the pressurized transmission fluid to six destinations
28:09 1. Lubrication and cooling to the motor gear and conductive bearing
29:08 2. Through the fluid-to-coolant heat exchanger to remove or add heat
31:04 3. Cool fluid is sprayed on the stator frame and right side windings for cooling through a sparge pipe
32:24 4. Cool fluid is sprayed on the non-conductive bearing and the right side of the rotor
32:58 5. Cool fluid is dripped on the stator frame and left side windings
32:47 6. Cool fluid is sprayed on the left side of the rotor
33:48 Transmission fluid fill capacities
34:42 Video Section 4 - Electrical Components
34:50 MUST SEE The three-phase, four-pole, 48 slot stator
35:55 The milli-ohm resistance of the stator windings with a Hioki RM3548 Resistance Meter
36:48 High-Performance induction motors versus high-efficiency Internal Permanent Magnet Synchronous Reluctance Motors (IPM-SynRM)
39:30 The inverter and its connection to the stator
41:42 The stator temperature sensor
42:40 How the stator frame is mounted with the stator housing
45:02 Additional EV training opportunities at www.weber.edu/evtraining
45:18 Thank you for your donations
ABOUT US
Weber State University (WSU) Davis Campus - Automotive Technology Department - Advanced Vehicles Lab. A technical description and operational demonstration of the Tesla Model S Front Drive Unit (FDU).
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 / vibratesoftware to see the amazing NVH app for vibration diagnosis!
ADDITIONAL TRAINING FOR YOU
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
DONATE TO OUR DEPARTMENT
Please consider a donation to the Department of Automotive Technology at Weber State University here: advancement.weber.edu/Automotive

[@Dogpool]

People are paying many $ bills to get a teaching from this dude. We up here getting arguably a better experience then the class room in some ways, for free(ish). Awesome time we live in.

[@tonybryan5181]

You can tell that the man loves teaching :

[@geik2]

If all teachers in the school system had been as good as you at explaining, .... Thank you professor

[@WeberAuto]

Wow, thanks! Thanks for watching!

[@user-ru2hf1sg4e]

This guy is the absolute best. I have watched his amazing videos and was able to pass my L3. Thank you so much!

[@WeberAuto]

That is awesome! Congratulations on passing your ASE L3 exam

[@user-ru2hf1sg4e]

@@WeberAuto thank you, i learned so much from you and cant thank you enough. You are an amazing teacher

[@WeberAuto]

@@user-ru2hf1sg4e Thank you

[@OkinSold]

Was waiting for this one! You are an excellent teacher!

[@WeberAuto]

Thank you very much

[@mikel4879]

Another excellent presentation. Thank you, professor !

[@WeberAuto]

You are very welcome. Thanks for watching

[@petermolnar6017]

Thank you Professor Kelly for your efforts to keep us informed! They are much appreciated!

[@WeberAuto]

Glad you like them!

[@WouterB76]

Long video? Yes. But if you want to explain something right down to the details, time has to be taken. Thanks for another insightful and clearly explained bit of Tesla technique!

[@WeberAuto]

Thank you very much

[@MattExzy]

That time flew by, really. Definitely didn't feel like a 46 minute video at all.

[@tonybryan5181]

Thank you (again!) professor for another illuminating session on the Tesla system. I know that there are many, many hours (days or weeks) of research and disassembly/re-assembly, editing and other real, unseen work that goes into your presentations. Thank you so much for these condensed, easy-to-understand tutorials on these very complex systems. Great nutrition for curious minds!

[@StanAnderson-yg7hj]

WOW, Professor Kelly is a wealth of information. He does an excellent job of explaining the inner workings of Teslas. Great job Professor.

[@sene-teckkservicesltd.7237]

Thank you Professor Kelly. You have made it possible for those of us in the developing world (I am in Ghana) to also learn and have an understanding of the new tech underneath the EV drivetrains. These videos are an absolute germ and it is my hope that we can all contribute to ensure its sustenance. Thank you once again.

[@tony39572]

Great videos. The high performance motors are induction machines to get around the problem of back EMF caused output power loss at higher speeds. Comes down to a tradeoff: Constant power over the full operational span at the cost of increased overall energy losses, or higher efficiency for decreased output power as speed increases? A magnet moving past a field creates a voltage proportional to the magnet strength and speed (back emf). A permanent magnet always has a strong magnetic field in the rotor. So, at some speed, the back emf exceeds the bus (battery) voltage and no more torque can be generated (flux weakening can help this, but eventually, no useful work can be done). But, because no rotor magnetization current is needed, PM based motors are much more efficient. None of the current in the motor is spent creating a magnetic field in the rotor. No rotor losses. For induction machines, the rotor acts as the secondary of a transformer. The current induced in the rotor (from the stator, primary) creates the rotor magnetic field that can then be used to create torque (via a process described as slip). This means the current in the rotor can be controlled. Because the current in the rotor can be controlled, the back emf can be controlled. Because the magnetic field in the rotor is controllable, constant mechanical power can be output until the variable frequency drive (VFD, converter) can no longer output higher frequencies. The penalty is rotor loses. Because there is current flowing in the rotor, induced by the stator, this power is lost in the form of rotor current (resistance of the rotor circuit). You have to pay, in terms of input electrical power, to create the rotor magnetization, therefore, less overall efficiency. But, constant mechanical power for the full operational frequency of the VFD. You can see this by spinning a motor by itself. A PM motor will generate a voltage as it freewheels, DMM between any two leads. (No current, because there's no circuit. Completing the circuit will make it a generator and the PM motor will act as a brake) An induction machine won't. (There will be a small residual voltage if it's an iron core, because of residual rotor margination, but not much) Applying a constant (DC) current to the windings of an induction machine (current limited power supply between one of the phase pairs, be sure to limit the power to something that won't damage the stator by too much heat), and spinning the rotor will make it feel like it turning thru peanut butter, the shaft will get stiffer as you try and spin it faster. Doing the same to a PM machine will make it 'cog' or make it unable to spin (by hand) at all. Be carefully at startup. It may turn very quickly with great force when current is first applied. If it's an IPM machine, there might be some cogging due to the motor saliency, e.g. the Nissan Leaf does this. I hope this was understandable and useful.

[@thebrain7693]

found this reply, very cool. was wondering if u know how induction motor can create regen. i just don't get how it can power the motor to induce field n receive current from motor at the same time...

[@shirothehero0609]

Weber! Been up there for some auto competitions back in the day and met you YEARS ago. Glad you guys are still one of the top schools for auto tech out there. Keep killing it WSU!

[@WeberAuto]

Awesome! Thank you very much

[@user-nr7uh9co4f]

Woo, another amazing video! Thanks a lot Professor Kelly! Your explanation makes the complicated stuff easy to understand!

[@cesarmartinez6708]

So glad I found your channel! Thanks prof. Kelly for yet another great video

[@WeberAuto]

You are so welcome!

[@credenceobliquy9604]

I know that your time, painstaking effort and expertise is very much appreciated. This is so interesting and you present it so well - thank you Professor. I like the fact that, notwithstanding your great knowledge, this is also rather a journey of discovery for you - it accentuates your enthusiasm which is as infectious as it is genuine. May I wish you a very Merry Christmas.

[@ahydeaway01]

You are an excellent person who has the ability to explain complex concepts in a captive dialogue. Thank you. From Mal R

[@WeberAuto]

You are very welcome

[@charliedevine6869]

Excellent video. I love seeing these parts exposed.

[@WeberAuto]

Glad you enjoyed it, Thanks for watching

[@Skarkroe]

Been watching since the 2nd Gen Volt videos. Now with a CyberTruck pre-order I’m enjoying the detailed dives into Tesla’s tech. Thank you so much for producing these!

[@WeberAuto]

Thanks for your long time support!

[@bergssprangare]

The best explanation of the Tesla motor set on Internet. Thank you

[@WeberAuto]

Wow, thanks!

[@Qbranch1024]

thanks Prof. Kelly for your and team's work on this video and for sharing it. I am so amazed at the the 17,000 RPM operating speed of the motor. I suppose that is what you can do when nothing reciprocates! Your videos about Tesla vehicles specifically also make it abundantly clear why they generally cost so much: it takes so many precision parts and so much design work! 😅 Happy Easter too 🌄

[@WeberAuto]

Thank you, Happy Easter

[@chuvvyyk]

This is the most comprehensive video about tesla motor! Thank you very much!

[@WeberAuto]

Thanks for watching!

[@lladosthechange]

Really good explanation of how the system is working thank you man for transfering tour knowledge

[@ErwinWernerTeichmann]

Very informative and detailed video. Thank you for sharing it Prof. Kelly.

[@WeberAuto]

You are so welcome!

[@jean-clauded5823]

I'm very impressed with the level of knowledge transfer, and honesty when he says details about things he doesn't know. I wish when I had go to school, I had more professors like this that were driven for a quest for knowledge and not their ego or reputation. He also understands, as shown in these videos, that he could know everything in the world, but if he doesn't share it, that knowledge is useless. In his case, he shares what he knows, and honestly wants people to help him learn even more where he may not know something in as far a depth as he would like.

[@WeberAuto]

Thank you very much!

[@ahmadfaisal6778]

Thank you sir for the video. I really admire your dedication.

[@WeberAuto]

So nice of you

[@Rei_n1]

Thanks for your great effort and making this material publicly available! Excellent! Top marks, it i may! 😀

[@WeberAuto]

Thank you

[@victorhoe2321]

Professor John Kelly, I was once an Electronics Tech at Weber State College, working for Sid Jensen back in 1969 through 1973. I wish I am younger to attend your classes on line or in person. I am a life long techie and find your teaching as excellent. The circular lecture hall was brand new in 1969. I did a Google Map of Weber State University, showing Engineering Technology Centre with what seems tobe new construction of Engineering Tech buildings.

[@bossmanmce5599]

Excellent Professor John -hope to join you soon in person

[@fascistpedant758]

Thanks for another great video. It's nice to get reliable, well researched information. Thanks for sharing.

[@WeberAuto]

Thanks for watching!

[@Martinsp16]

Easter 🐣 is early this year. Thank you for another great video professor :)

[@WeberAuto]

So nice of you, Thanks for watching

[@democracymontano]

Thank you for sharing knowledge captain!

[@jimsumire892]

Professor kelly, your tutorial is very well produced, it is excellent, thank you very much for sharing it, from Peru

[@WeberAuto]

My pleasure. Thanks for watching

[@kenhelmers2603]

I find these videos fascinating! Thank You

[@WeberAuto]

Thanks for watching!

[@Jiefyang]

I’m drooling, great detail, clear delivery and hella good vid!

[@WeberAuto]

Thanks for watching

[@Shiftheads]

So glad you are doing these videos! Top notch quality. Are you still doing the one week class?

[@WeberAuto]

Yes I am. We have four more scheduled this year. See www.weber.edu/evtraining for the schedule

[@Shiftheads]

@@WeberAuto great! Thank you!

[@tianjohan4633]

I would love to see you do a tear down with the new model 3, with the octo valve and heat pump. Great videos.

[@WeberAuto]

Coming soon! Thanks for watching

[@war6193]

Thank you for making these excellent videos.

[@WeberAuto]

Thank you

[@saftschubse9575]

These videos are amazing. The have so much information in them which you dont get normaly.

[@WeberAuto]

Glad you like them!

[@user-bn5cx9do8t]

Excellent presentation professor

[@WeberAuto]

Glad you liked it!

[@rogergreeson7968]

Thank you sir for fine instruction. Truly enjoyable presentation.

[@WeberAuto]

You are very welcome

[@user-fs8lz9re2q]

Wow this was so good, learnt a lot huge Tesla fan and they have some amazing tech chemistry going on in their motors.

[@WeberAuto]

Thanks for watching

[@RHaddadzadeh]

Hello Professor. thank you for your efforts and great videos!!!

[@mayankbalakrishnan1089]

Thank you for this awesome informative video.

[@WeberAuto]

Glad you enjoyed it!

[@user-bx5zy1mu3v]

As always great video, good explanation, thank you very much!

[@WeberAuto]

Thanks for watching

[@bwest-yq3uc]

Very Educational....Keep up the Good Work.

[@WeberAuto]

Thanks, will do!

[@randyhavard6084]

Great information from a great teacher

[@WeberAuto]

Thanks for watching

[@katout75]

Phenomenal reverse engineering presentation on a variety of Tesla electric motors and gears. Thank you for creating these extremely informative technical video's.

[@WeberAuto]

Thank you very much

[@Martin-se3ij]

i can only imagine the hours that have gone in to clean all these parts. You are opening my eyes to the amazing engineering that goes into these cars. Who would know your front wheels are a different size than the back, I'm sure owners would just rotate the tires thinking them the same?

[@WeberAuto]

Thanks for watching

[@jon-williammurphy9780]

Simply invaluable, as an ME that wanted to learn more about how these systems work, this level of quality and no BS is a Jahsend. Regarding HX, I would assume counterflow, so if you know the oil flow direction you know the coolant probably flows the other way

[@WeberAuto]

Thank you. Good point!

[@Pablo_Automotive]

Thanks a lot for your explanations this is really handly

[@WeberAuto]

You are welcome!

[@ekimbrough1413]

Long video, but vveeerrryyy satisfying!

[@aymanwaleed5228]

Thank you sir Even with some mistake you still the greatest Stay safe

[@WeberAuto]

Thanks 👍

[@asayake1]

my eyes are on a rav4 prime... but i still love learning about how teslas do what they do. thank you for sharing your knowledge!

[@willusher3297]

Yes, your hypothesis was correct - the more efficient PM motor is used to supply most (all?) torque under certain conditions (e.g. highway cruising). Elon said this was how they are able to get increased range out of the AWD version of the S. It would be interesting to know more details on when this is done (I suspect it's not as often as possible, since the driven wheels affect the handling). Great series. Thanks for all the effort you put into these. I'd love to see more details about the power electronics (inverter) - maybe bring in an EE professor to go deep on the circuit-level design?

[@WeberAuto]

Thank you and thanks for the suggestion

[@shaunryan6]

Most extra range is from putting more batteries in the car.

[@ApteraEV2024]

It would be sweet if that was the model s in the background...😊 (thanks for sharing John!)

[@digicreator1]

A man that can except his errors…is someone I will trust with the information given 😌

[@mikecawthorn7806]

Tks Bud. Great work.

[@bruceritchie7613]

Thank you for the informative video! I'm a bit surprised that Tesla would change the lubricant between revisions. I wonder if they were being cautious initially and decided that it wasn't necessary or whether they changed bearings in newer revisions that allowed them to go with a less expensive and lower quality lubricant.

[@WeberAuto]

Thank you. I wondered after shooting the video if the Dexron VI is for the 2019 and newer PM motor drive unit. Revision J is the one I am looking for now. Thanks for watching.

[@theonlymadmac4771]

Very interesting video ( as your videos generally are). Thank you!

[@WeberAuto]

Glad you like them! Thanks for watching

[@robotfootage]

@weberauto - To answer your question on how the car utilizes power distribution to the motors; Teslas primarily use the rear motor until throttle % or motor load reaches a certain limit, then it powers up the front motor as well. We can see this in ScanMyTesla, or any other OBD scanning tool while driving and logging. Cruising speeds and light load is always isolated to the rear motor only. Hard acceleration or when traction control is activated on the rear axle, is when the front motors engage.

[@WeberAuto]

Great information, thank you!

[@ecstatic8696]

Fantastic and exciting to see this--thank you. I wonder if there is an attitude like a steep hill at which the motor's lubricant pump gets starved for oil; this would probably be helpful for owners to know so they could avoid motor damage.

[@antoniostefanile]

Hello, great explaination as usual. How long in your opinion bearings on main motor shaft can handle the maximum RPMs?

[@maitilupas]

this is amazing thank you !

[@jamesbruce1183]

As you drive down the road it puts the induction motor in 'torque sleep' mode (0 torque). It uses the PM motor only to drive the car. At some point in the application of the accelerator it starts using moth motors. I think torque sleep puts enough power to the induction motor so the output torque is 0 reducing drag and increasing efficiency.

[@WeberAuto]

That is what I suspected, thanks for the information

[@justinmallaiz4549]

I don't think induction motors have any rolling drag ( besides bearings) .. The permanent magnet motor obviously do

[@jamesbruce1183]

@@justinmallaiz4549 I did not invent the term 'Torque Sleep' but read it in a Tesla document. I assume it has a purpose. Perhaps turning the motor ~9 times faster than the axles while the rotor is covered in oil creates/requires enough axle torque to require nulling out.

[@wernerfritsch6436]

The use of induction motors as secondary motors has the advantage that they do not generate any voltage (and do not introduce any drag) when they are not used but driven from the wheels. The inverter simply does not feed any current or voltage to the stator in this case and thus introduces no energy losses.

[@voyageblue3947]

easy understanding introduction

[@WeberAuto]

Thanks for watching

[@IAMNOSLEEP]

Thanks for sharing Professor... Cheers.

[@WeberAuto]

My pleasure!!

[@mikenelson8351]

Brilliant and thanks (Mike from Australia)

[@WeberAuto]

Thank you!

[@joseramonherreramendoza9260]

AMAZING VIDEO AS ALWAYS... GREAT JOB PROFFESOR... THANK YOU SO MUCH ☝️🤓🤓🤓🤓🤓🤓🤩🤩

[@WeberAuto]

Thank you very much

[@oisiaa]

Have you already done the Model 3 front/rear motors? I looked, but couldn't find videos on those. Can't wait for them!!!!

[@WeberAuto]

Coming soon!

[@oisiaa]

@@WeberAuto Can't wait! Videos should be a hit. There are way more of those cars out there with curious owners.

[@hamadalharasi3355]

Nice to see you again sir thank you very much for the after long time thank you for the The video is rich in information god bless you always 🇴🇲

[@WeberAuto]

So nice of you

[@swaminathanraju6883]

Best information.Thanks lot.

[@WeberAuto]

So nice of you

[@allterrainrandy2587]

Excellent video! Thank you so much. Any idea of the weights of the complete drive units?

[@WeberAuto]

Thank you, I do not know.

[@versatilevijayr8475]

Sir, all your videos are excellent. Can you please help us to understand on how two or more motors are controlled using a single accelerator input signal. How torque on demand from wheel and accelerator input are taken into controller and how the power is distributed to twin or more motors.

[@WeberAuto]

The two motor controllers communicate with each other and other modules to keep everything synchronized as needed. Thanks for watching

[@robertdercole8201]

Hi there from down under in Australia. I have recently acquired a Tesla model S front and rear small drive unit and a large rear drive unit. I will be fitting these mounted longitudinally in a Land Cruiser 4x4 project. I note with interest that the front and large rear you have covered are both fitted with oil pumps. I intend to run these motors in reverse rotation in my application. Would you know if the oil pumps in either one will continue to pump oil running backwards? Your video's are really excellent too and already a great help to me in understanding EV tech. thanks.

[@ckafam]

Hi. Could you please include the weight of each drive unit and include the info in your description? Thanks, great video.

[@BFTVCanada]

Thank you for this well done video! Makes me appreciate my P85D more 😅

[@pablopicaro7649]

Another Great video

[@WeberAuto]

I appreciate that

[@alexanderstefanxandraswedi5835]

Great job

[@m.j.7743]

Thanks for great video. I enjoy every video from you. You compared two rotos with diameters lengths. Comparing the lengths should be usually effective active length. It means the lengths in it is the magnetic circuits. I don't know if you used the total length of the rotor with the both rings.

[@WeberAuto]

I realized after the video was published that I swapped the rotor dimensions of diameter and length. Sorry for the confusion.

[@m.j.7743]

@@WeberAuto I love your videos. Thank you so much.

[@Friedbrain11]

I suspect you are correct about the perm motors in the Tesla cars.Great series :)

[@WeberAuto]

Thank you and Thanks for watching

[@rimooreg]

Professor Kelly, just one question: how to you put up with the beating that chair delivers? I bought a Permobile C 350 as it allowed me to go up and down high curbs with no jarring from sitting over the drive wheels.

[@dewiz9596]

So much useful information!

[@WeberAuto]

Glad you think so! Thanks for watching

[@traviscalvin431]

Another amazing video Professor. Thank you for sharing with the world. I have the bluetooth dongle and ScanMyTesla app in my Model Y AWD. It shows that the front motor rarely gets used. Looking at the first log file that I could find it only used power starting at 30% accelerator. I had a Chevrolet Volt prior to the Tesla and during regen braking (in "low" gear as I usually drove) on icy roads the front tires would lose traction and cause some scary situations. After that experience I specifically wanted my next EV to be AWD to keep it from happening. Looking at the Tesla's log data it appears that it still only uses the rear motor for regen almost all of the time even though it has the ability to use the front for regen. The good news is that Tesla's software is smart enough to recognize when the regen is causing an unsafe situation and adjusts as I have never felt tires lose traction during regen braking. Tesla's regen braking on icy roads is more steady than the ABS when you need to use the mechanical brakes.

[@WeberAuto]

Excellent information! I just purchased the app and cable for our Model S. I look forward to gathering and sharing some data related to these motors. Thanks for watching

[@manuntunoficial6701]

an excellent trainer

[@WeberAuto]

Thank you!

[@blacklineindustries7602]

@WeberAuto I realize this video is a year old now and without checking all the comments, I don't know if someone already mentioned this but there are two different rotors for the LDU. The Base & Sport LDU's have different rotors. The Base rotor has less copper fill than the Sport rotor. The Sport rotor is completely full to the ends of the rotor. The Base rotor has a bit of a "bowl" where there's a void of copper. I think there's a lot of internet lore floating around that says both LDU motors "are the same" and that only the inverter is different but the rotors are definitely different. The LDU stators may or may not be the same. That's much harder to check since the stators are encapsulated.

[@AnibalCattaneo]

U R the best!! tanks from Argentina

[@WeberAuto]

Thanks for watching

[@matthewknobel6954]

would there be any benefit in range/efficiency of using a smaller motor with a 2+ gear transmissions or cvt? If we were looking at normal 0-60 times of around 7 sec I would think that one gear for acceleration and one for highway speeds would be better then to put in one motor that may be oversized to cover an entire torque range.

[@Bassotronics]

I thought those vehicle motors were much bigger. 259 hp on that little motor is amazing!

[@WeberAuto]

They are amazing! Thanks for watching

[@szekelyharry]

Hello from Romania ! It is a pleasure to watch your exceptional videos! I love them! Please, could you explain how Renault E-Tech system works ? Thank you!

[@WeberAuto]

Great suggestion!

[@bukurie6861]

Thank you so much Prof.that are explein for Tesla S and😍 Front Motor❤🌏

[@MiguelRodriguez-nt5eq]

Awesome video once again.. Ive always wonder how hot those staters get?

[@WeberAuto]

Thank you, good question. I hope to find out

[@san080890]

Thanks for the video.

[@WeberAuto]

You are welcome!

[@TheCRDMiller]

Shc629 is also used in dyna pack vibratory drum cartridges.

[@WeberAuto]

Good to know, thank you

[@bidhanpandey4020]

Great video! Why is a smaller diameter tire used in the front as compared to the rear?

[@MrSanderOne]

Hi - great video. I have same size tires on front and back on my winther 19". Summer is 21" with different sizes as you mention. All original.

[@eugeneputin1858]

Yes it's the back motor thats there for main propulsion. Once you floor it, both of the motors engage instantly. Wish there was an option to lock into awd for snowy/icy conditions.

[@WeberAuto]

Great information, thank you

[@ziggyyo]

30:36 To heat cold batteries of not moving cars, the stators are powered with about 1-3 kW and are used as heat source when necessary. The stator heat will also heat up the lubrication fluids in the gear box.

[@WeberAuto]

Great information, thank you

[@Stefan_Dahn]

This is only the case on Model 3 and Y, where Tesla puts DC current on the stator to use it as a heater. But also while driving (to a SuperCharger for preconditioning the battery) modulating some part DC current onto the AC current. The Model S and X have a seperate heating device, for heating the water by battery-DC.

[@Rei_n1]

Model 3 perf ir mostly rear wheel driven in the winter (and thus unmistakably appears less stable on a slippery roads), model s vice-versa - feels primarily front wheel driven. In the wintery conditions ir is very obvious by vesicle behaviour. Thus your hypothesis that the more efficient motor is predominantly used in daily low performances scenarios agrees with winter driving observations. You are spot on.

[@WeberAuto]

Thanks for the great information

[@tonys8243]

Thanks professor Kelly ..

[@WeberAuto]

You are welcome!

[@McDaniel77]

Prof. Kelly I didn't know that the electric parts of the motor are lubricated too, I always thought these motors are complete dry and I wondered how it's possible to cool them. Thank you for the great details you offer. Tesla uses only one permanent magnet motor, because if you have two of them, they give you resistance by being a generator, the iduction motor can run free without inducing any currents. So I guess, when the vehicle is cruising at constant speeds, it will just be powered by the high efficiency reluctant permanent magnet motor, while the induction motor is just idling. Greetings from Bavaria Germany, I bet you have german roots! ;)

[@WeberAuto]

Thank you and thanks for the great information. I suspected that was the situation.

[@brianb-p6586]

You can use two PM motors. Other AWD production EVs use PM for both axles.