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Does electric motor performance degrade?

SomeJoe7777

Marginally-Known Member
Mar 28, 2015
2,165
5,533
Houston, TX
Oh no, they are not. coolant out of the very complex cooling system. Some have coolant inside their car too.

While the cooling system has a lot of components, the system is far less prone to failure compared to an ICE cooling system for several reasons:
  1. The system is not pressurized beyond the pump driving head, so no high-pressure seals or metal containment vessels are required.
  2. The highest temperatures are in the 120F-140F range, well below the boiling point. So no steam vent, expansion tank, or pressure relief systems are required.
  3. Maximum flow speeds are far below an ICE cooling system. This reduces wear in the system, and does not require a large impeller pump.
As a result of the far less harsh conditions, many parts can be made of plastic, reducing cost and maintenance requirements, while eliminating corrosion concerns. Leaks are far easier to fix, involving a simple replacement of a hose or inexpensive plastic component.
 

john5520

Member
Mar 3, 2020
776
513
Florida
I've seen more comments of puddles under Tesla's than I've seen on most ICE Forums.

Hmmm, if my motor mounts ever wear worn out, I just replace them. Problem is, I have not seen a bad motor mount in decades.
But I only ran my ICE cars to about 200K miles.

Tesla's have plenty of bushings to wear out too.

Next you'll be saying EV's don't wear out tires too.

Tesla's are pretty complex, probably have more fluid in them than most ICE cars do.

The puddles under Teslas generally turn out to be condensation from what I've seen. Coolant leaks happen, but compared to years back, posts about them now are scant.

The belt-driven assembles in an ICE car are subjected to more stress and heat which leads to degradation of the fluids, internal components, gaskets and hoses. So, leaks are common as the miles pile on.
Just the temp factor alone is a big disadvantage.

And from what I've seen, high mileage ICE with a little service history are mostly highway-driven, lower powered cars with conservative drivers. As the performance goes up,
the issues go up as well as the maintenance costs with few exceptions.

Yes parts that EVs and ICE share in common will need maintenance, but overall, the powertrain of an ice is more prone to issues.

Even with the complexity and glitches of a Tesla, the kinds of problems I see posted here pales into comparison to what's posted on ICE forums. I'm not talking about the cosmetic stuff. Just things that affect driveability.
 
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Dolemite

is my name
Sep 19, 2019
1,095
1,319
ol' Virginny
While the cooling system has a lot of components, the system is far less prone to failure compared to an ICE cooling system for several reasons:
  1. The system is not pressurized beyond the pump driving head, so no high-pressure seals or metal containment vessels are required.
  2. The highest temperatures are in the 120F-140F range, well below the boiling point. So no steam vent, expansion tank, or pressure relief systems are required.
  3. Maximum flow speeds are far below an ICE cooling system. This reduces wear in the system, and does not require a large impeller pump.
As a result of the far less harsh conditions, many parts can be made of plastic, reducing cost and maintenance requirements, while eliminating corrosion concerns. Leaks are far easier to fix, involving a simple replacement of a hose or inexpensive plastic component.
Also instead of having engine oil + transmission fluid + differential fluid, there’s only the gearbox oil. There’s also no gasoline...

That being said, modern ICE vehicles are insanely reliable and I don’t understand the poo pooing that they get on these forums, either. At this juncture, if I had to put my money on a Model 3 vs a Corolla lasting to 300,000 miles on the original components, it would be on the latter. But nobody actually wants a Corolla. Let’s hope I’m wrong, because we’re all taking somewhat of a gamble here.
 
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bruce4000

Member
Jul 8, 2019
156
238
Seattle
Other than a manufacturing problem, the main reason electric motors fail is if you overheat them for too long which can break down the insulation. Unless you are towing a house over the mountains on a summer day I wouldn’t worry about it. Elon has said that once they get a better battery, the drivetrain should last a million miles. Also, these are not DC motors that have brushes like Cheapo power tools.
 
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afadeev

Member
Feb 28, 2019
691
615
NYC
Are you willing the ignore the eventual oil, coolant and transmission fluid puddles under the ice?

You do know that TM3 *has* oil, coolant, refrigerant (lines and fluid), and transmission, right?
And that, eventually, they will leak.
:rolleyes:

Or the engine dancing in the engine bay on worn out mounts?

... and the engine (-s), which are held my engine mounts?
And the battery?
:cool:
 

Uncle Paul

Well-Known Member
Nov 1, 2013
6,105
6,607
Canyon Lake,CA
At the last Monro Model Y teardown, Sandy took special note of the high quality connectors Tesla was now using for fluid and electrical connections. Said they were highly resistant to vibration, aging and should result in extremely long lives. Big difference from the clamp and radiator hose connections used on most ICE builds.
 
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ZOMGVTEK

Member
May 19, 2015
558
433
'Merica
The major issue with ICE vehicles is the thermal cycling they’re subjected to. The fluids in EV’s don't get super hot all the time. Fluid leaks are certainly common on old ICE cars, but the trouble is the oldest a Model S can be really isn’t that old. So it’s a bit problematic to compare at this time. Although I would tend to agree EV’s are way less likely to have leaks, they aren’t usually that big of a problem in an ICE anyways. Well designed ICE vehicles are almost guaranteed to be more reliable than a current gen Tesla. They have a lot more time and experience, plus the repair infrastructure is mature. The problems with age in an ICE are still present in a Tesla, they just happen to have complex electronics that only the dealer can service in addition.
 

pacopico

Member
Mar 3, 2020
16
32
Gig Harbor, WA
In my professional life I deal with 3-phase alternators behind medium speed diesel engines, which are on average 2.5mWe rated.

A 3-phase alternator and 3-phase induction motor are very similar in their operation, and I would presume as well their degradation is similar. Over the course of a generator sets' life the operators typically track overall efficiency of kWh/Gal, and from my experience though the kWh/Gal can vary due to engine condition, fuel density, atmospheric conditions, etc. when you average everything out over years, the the consumption is rather consistent.

One of the highest hour generator sets I know of in my area that is currently in-service has ~170,000 hours on it, average load of 60%. In a power generation application the engine would be overhauled about (4) times in this period, with no work done to the alternator other than lubrication of the end bearing and replacement of the bearing only as needed.

If you figured a typical car travels at a lifetime average of 33 MPH then 170,000 hours = 5.61 Million miles.

This particular genset went into service in the mid 1980's, runs about 5,000-6,000 hours a year.

Maybe not apples-to-apples but there are some parallels.
 
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SomeJoe7777

Marginally-Known Member
Mar 28, 2015
2,165
5,533
Houston, TX
One of the highest hour generator sets I know of in my area that is currently in-service has ~170,000 hours on it, average load of 60%. In a power generation application the engine would be overhauled about (4) times in this period, with no work done to the alternator other than lubrication of the end bearing and replacement of the bearing only as needed.

I agree. I served in the US Navy as an electrician in the early to mid 90's, and serviced turbine generators and motor generators that were 30-35 years old. Other than occasional bearing lubrication, nothing was wrong with them, and they continued generating electricity long after I was gone.
 

john5520

Member
Mar 3, 2020
776
513
Florida
You do know that TM3 *has* oil, coolant, refrigerant (lines and fluid), and transmission, right?
And that, eventually, they will leak.
:rolleyes:


... and the engine (-s), which are held my engine mounts?
And the battery?
:cool:

Haha. DU and coolant leaks are rare. Mount problems are rare too. As discussed already, the majority of components in an EV operate under less heat and stress unlike an ICE car.
 
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Char

Member
May 29, 2019
17
23
Mississauga, Ontario
@Char Which are your thoughts regarding my post? Why do you disagree? I'd like to know your opinion.

Sorry, I must have accidentally touched something that registered a disagree. I usually just surf around various topics here. I use an iPad so it’s easy for fingers to brush across links accidentally. No disagreement intended. Sorry!


Edit: just figured out how to cancel that disagree and have done so!
 

wws

Member
Aug 11, 2014
864
868
Northern California
Say that to the 500-750k club guys that are SAAB and Mercedes owners.

This former Mercedes owners car went about 100K miles before it needed major engine repairs. ($$,$$$ if the dealership did the work, high $,$$$ if my former German car mechanic did the work.) Traded it in on my Model 3.

Elon stated a few months ago that the Model 3 drivetrain was validated to one million miles. However the battery packs were only validated to 300K miles. (E.g., 1000 charge/discharge cycles on a LR pack.) He has a goal of extending the battery packs to a million miles as well. Said SpaceX was already using cells that could do it. Hopefully we will hear more on Battery Day.
 

SageBrush

REJECT Fascism
May 7, 2015
12,084
14,993
New Mexico
However the battery packs were only validated to 300K miles. (E.g., 1000 charge/discharge cycles on a LR pack.) He has a goal of extending the battery packs to a million miles as well. Said SpaceX was already using cells that could do it. Hopefully we will hear more on Battery Day.
I look forward to a standardized test based on 200 kW DC charging.

I personally do not DC charge much so I don't expect to be affected but battery longevity despite DC fast charging is something of holy grail for now.
 
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Feathermerchan

Active Member
Sep 21, 2018
1,098
843
Euless, Tx
Even though motor performance and efficiency and battery performance degrades, if the system controlling the motors operates by a certain power output, the driver may never notice it. As long as the battery is capable of providing the commanded output and the motor is also capable, there is no reason for experiencing reduced output while driving.
In this respect EV's differ from ICE. When you floor your ICE, presumably the computer opens the butterfly fully and you get all she's got. But an EV has good reason to just command a certain HP output to prevent harm to the drivetrain. So over time that output can be maintained so long as the battery can deliver.
 
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