What's the Slate's maintenance like?

[AZFox]

I'm going with 400,000 miles as "never".

Reasonable enough, but 400K with zero failures is the exception, not the rule.

 

[E90400K]

I would say that moving parts fail quite often, but i am probably biased since I am in the auto repair business and have been for my entire career... Modern cars are value enginered to be as reliable as possibe until the warranty ends.

Just recently GM recalled over 600,000 vehicles due to manufacturing defects that caused catastrophic engine failures because of, wait for it... bearing failure!
https://gmauthority.com/blog/2025/0...heres-how-many-engines-gm-expects-to-replace/

Time will tell if the Slate is a reliable vehicle, but it is at least looking like one on paper.

Maintenance is cheap depending on the vehicle, and if done right you can expect a vehicle to last a long time.
But just an oil change is going to run you $50-$100, every 3-5,000 miles (yes, you can stretch that out, but the risk of failure goes up if you do). Over 10 years (10k/year) that is $1k-$2k, plus you consumed about 50 gallons of oil that has to be dealt with. You will not have to bear with an EV. that combined with fuel savings makes EV's compelling for a total cost of ownership standpoint.

That's a manufacturing defect that should have been picked up by statistical process control, not an intrinsic attribute of the moving part. Build an EV battery incorrectly and it catches on fire.

 

[E90400K]

Reasonable enough, but 400K with zero failures is the exception, not the rule.

Okay, then I'll go with 256,000, or 230,000, or 200,000. All "never" in my book. It's not luck, it's good engineering and proper maintenance. The 200,000 miler is in it's 28th year of service. The 256,000 one was 18 years old when I sold it, the 230,000 one was 13 years old. I'm just saying ICEV have a very good track record despite the massive amount of "moving parts".

But the BMW N52 is well known for its longevity. 300,000 miles is the rule.

 

[Trace26]

Okay, but really how often do such moving parts actually fail? Modern automobiles are so well engineered and manufactured the moving parts rarely break. I've driven 1.6M total miles in my life spread over eight (8) cars, of four that have gone over 400,000 miles, 256,000 miles, 230,000 miles, and 200,000 miles. Others easily hit 100,000+ miles before I sold them or they were damaged beyond economical repair. Never have I lost and engine or transmission. Hell, my 400,000 mile BMW had a lifetime oil change average of 12,300 miles, with eight changes over 17,000 miles between. The maintenance is not that expensive. Just because the parts move doesn't mean they are any more prone to failure than other non-moving parts of an EV. I'll point to the Ford Mustang Mach E HVB junction box (well the moving contactors fail in it...). Sure, an electric motor drive unit has less rotating parts, it still is subject to heat and thermal expansion and requires proper lubrication (it has an oil pump and gears) and can fail.

The bearings in an automobile that really take shock, and are prone to heat and dirt infiltration damage are wheel bearings, which EVs have. All EVs have axleshafts just like ICEV. Modern ICEV automatic transmissions have oil change requirements between 60,000 and 100,000 miles. The moving parts that really wear on an ICEV are the axles, suspension bushings and struts/shocks, same components an EV has.

Engines run between 230 to 270 deg. F. Steel and aluminum melt at temperatures 5x to 10X higher than that. Sure, the plain bearings get hot, but they are engineered to get hot and they last for millions of duty cycles.

I think the biggest difference with the reliability of an ICE vs EV is the maintenance. You can get the same reliability from an ICE vehicle with proper maintenance and it may not be that expensive if you perform the maintenance yourself.
But if you did zero maintenance on both, the EV could be perfectly fine for more than 100,000, but the ICE engine will probably seize up after 30,000miles.
The average person doesn't do proper maintenance and not having to do much, if any, is a plus.

 

[KJRaven]

That's a manufacturing defect that should have been picked up by statistical process control, not an intrinsic attribute of the moving part. Build an EV battery incorrectly and it catches on fire.

Discounting manufacturing defects is no different than discounting improperly maintained vehicles. The point is that if there is something that can go wrong it will go wrong. The amount of things that can fail in an EV are drastically less than the amount that can fail in an ICE vehicle. There will be failures though.

ICE vehicles have had over 100 years to develop, EVs are in their infancy comparitivly, and are already proving that they just as reliable if not more reliable than their counterparts. The future is bright, and not because of the inevitable EV fires /s

 

[E90400K]

I think the biggest difference with the reliability of an ICE vs EV is the maintenance. You can get the same reliability from an ICE vehicle with proper maintenance and it may not be that expensive if you perform the maintenance yourself.
But if you did zero maintenance on both, the EV could be perfectly fine for more than 100,000, but the ICE engine will probably seize up after 30,000miles.
The average person doesn't do proper maintenance and not having to do much, if any, is a plus.

Can't argue that point. I kind of look at cars like people did back in the days of the horse. Proper maintenance of horses is critical to their longevity. I take the horse route. Cars are way easier.

 

[AZFox]

I'm just saying ICEV have a very good track record despite the massive amount of "moving parts".

I understand what you're saying. I think the reason you are getting such good results is because you're on the ball about maintenance. You're exceptionally (pun intended) good at making cars last.

The average person doesn't do proper maintenance and not having to do much, if any, is a plus.

This.

 

[Driven5]

But the BMW N52 is well known for its longevity. 300,000 miles is the rule.

Let's be clear here though. Sure plenty of engines are capable of achieving unnecessarily (from a manufacturer perspective) high mileage... But all of that moving part longevity comes at a not insubstantial lifetime preventative maintenance cost.

BMW has some of the neediest engines I've experienced from a preventative maintenance standpoint. Beyond the typical (many) oil/filter changes and whatnot, never before owning an N52 did I have ANY engine need an 'oil filter housing' (dumb non-integrated design) gasket, valve cover gasket, and oil pan gasket replaced every 100k or so. I'm not sure why, but they couldn't engineer a gasket rubber to save their lives, despite other manufacturers having figured it out decades ago. Same with the ~100k limited-life electric water pump and thermostat. The whole ownership experience was best summed up by 'so close, yet so far'.

I mean, Subaru fanbois can brag that their EJ25 has 300k longevity too... It just needs to be fed a steady diet of head gaskets.

 

[JoeUser]

As a former Tesla master technician, I would compare the Slate to a 2018-2020 model 3 in terms of complexity.

Tires and cabin filters should be the only maintenance items for the first 100k.

In theory, brake fluid, gearbox oil and coolant should be replaced at around that mark... In practice it's not critical. The dirty, extremely hot combustion engine and increased brake usage just wear those fluids out in a combustion vehicle. An EV is just much less demanding and the temperature/usage is so much lighter.

Brakes: I saw exactly one model 3 that had actually worn out it's brake pads and required replacement. One. The entire shop came and took a look it was so rare. Anyone who says BRAKES wear out faster on an EV are just dead wrong. In normal driving (non-salted roads) the brake pads can outlast the car.

Suspension is the same as any vehicle. Eventually it all wears out and requires replacement.

That said, new company, new vehicle. There will be failure points and design flaws. I wouldn't consider that 'maintenance' exactly, but it could end up requiring that. Time will tell.

 

[AZFox]

As a former Tesla master technician, I would compare the Slate to a 2018-2020 model 3 in terms of complexity.

Tires and cabin filters should be the only maintenance items for the first 100k.

That's encouraging to know. Thanks.

That said, new company, new vehicle. There will be failure points and design flaws. I wouldn't consider that 'maintenance' exactly, but it could end up requiring that. Time will tell.

Decades ago a "first year car" was presumed to have flaws. Everyone expected that.

Even farther back (say, 1960's and before), virtually all new cars , first-year model or not, were presumed to require a few trips back to the dealer to have some deficiencies rubbed out.

Flash forward to today and we have high expectations.

Here's hoping Slate Auto can achieve a high Quality Score from the get-go.

 

[OldGoat]

As a former Tesla master technician, I would compare the Slate to a 2018-2020 model 3 in terms of complexity.

Joe! Way to cut through the fog here. Can't help but ask you questions I've had for a few years. When E-bikes came out the motors and controls were all over the map with many crappy suppliers and assemblers jumping into the market. Most bike shops simply wouldn't allow any E-Bike service on anything they didn't sell. Not entirely because of fire concerns which is what they told the owners on junk bought over the internet. It had a lot to do with a total lack of repair parts and serviceability. Will EV's of various brands begin using the same suppliers for their E-systems so independent mechanics can do cost effective repairs at some point? And will there be enough service for EV independent garages to begin popping up in larger markets? How do you see EV service playing out in the coming years? Any hope of plug-n-play battery replacements?
With E-bikes, there are about 5 proven drive suppliers who sell to a wide range of bike brands. And about the same for disc brakes that will safely stop a heavy E-bike. That allows a shop of brand A to service brand B since it might have the same Bosch or BaFang drive as his brand A. Now that he's got brand B customer in the door, he can sell him unlimited accessories and even service "packages".

 

[Dorbiman]

Okay, then I'll go with 256,000, or 230,000, or 200,000. All "never" in my book. It's not luck, it's good engineering and proper maintenance. The 200,000 miler is in it's 28th year of service. The 256,000 one was 18 years old when I sold it, the 230,000 one was 13 years old. I'm just saying ICEV have a very good track record despite the massive amount of "moving parts".

But the BMW N52 is well known for its longevity. 300,000 miles is the rule.

I won't pretend like ICE engines and transmissions are just waiting to explode, but let's not pretend like they're just happy as can be for all 200K, 230K, 256K, or whatever miles. In that time you WILL have had to do spark plugs, coils, valve cover seals, timing belt/chain, cam seals, etc. At 400K, I would assume your rear main has been seeping for the last 100K miles. If it's an automatic, the clutch pack is probably about shot, if it hasn't been rebuilt already. If it's a CVT, there's no way it lasted to 400K in the first place! haha

My Silverado is a trooper. Been going great since '05. But dear god don't look at the under carriage covered in oil from the numerous leaks. And the LS engine is ALSO known for fantastic longevity, especially the ones without Displacement on Demand, like mine.

Don't get me started on the Subarus I've owned. Head gaskets every 100K miles, Duty C solenoids causing hard shifting and slipping, etc.

 

[E90400K]

I won't pretend like ICE engines and transmissions are just waiting to explode, but let's not pretend like they're just happy as can be for all 200K, 230K, 256K, or whatever miles. In that time you WILL have had to do spark plugs, coils, valve cover seals, timing belt/chain, cam seals, etc. At 400K, I would assume your rear main has been seeping for the last 100K miles. If it's an automatic, the clutch pack is probably about shot, if it hasn't been rebuilt already. If it's a CVT, there's no way it lasted to 400K in the first place! haha

My Silverado is a trooper. Been going great since '05. But dear god don't look at the under carriage covered in oil from the numerous leaks. And the LS engine is ALSO known for fantastic longevity, especially the ones without Displacement on Demand, like mine.

Don't get me started on the Subarus I've owned. Head gaskets every 100K miles, Duty C solenoids causing hard shifting and slipping, etc.

You can find all the details about my 400K E90 on the E90Post Forum if you'd like to read about it. Starting at 200,000, 300,000 and finally at 400,000 I documented the car's maintenance and repair history, so I'm not going to rehash all of the history here. In May 2025 the car got caught in a flood event, which made it not economical for me to repair it. The final mileage was 426,843 miles. And I drove the ever-living piss out of the car for the 19 years I owned it.

But all of your assumptions are incorrect.

 

[Dorbiman]

You can find all the details about my 400K E90 on the E90Post Forum if you'd like to read about it. Starting at 200,000, 300,000 and finally at 400,000 I documented the car's maintenance and repair history, so I'm not going to rehash all of the history here. In May 2025 the car got caught in a flood event, which made it not economical for me to repair it. The final mileage was 426,843 miles. And I drove the ever living piss out of the car for the 19 years I owned it.

But to address your assumptions. Both the front and rear crank seals were original at 426K and leak free. I replaced the clutch at 293,340 miles. I did not replace the rear seal because several professional mechanics have told me if the seal is not leaking to leave it alone because there is a 50/50 chance the new seal will leak. I replaced the spark plugs at 100,000 mile intervals (one replacement was at 95,000). I replaced the rack of coils once when just one (cylinder 5) died at 287,685. I replaced the valve cover gasket once (305,020) and the oil pan gasket once (293,550). Cam drive (chain) and seals were all original, I never touched them. In fact, the N52 has a very sophisticated valve train because it uses both BMWs VANOS system and Valvetronic system. Each continuously adjust the camshafts for timing, valve lift and lift dwell. The Valvetronic system eliminates the throttle body, the N52 is throttled completely by adjustment of the intake cam valve lift and dwell. The serpentine belt I changed at 100,000-mile intervals. So, all your assumptions are incorrect.

BFD, the N52 has leaky gaskets, so do most engines eventually. My N52 started to leak oil well past 200,000 miles. Most people don't keep their cars 200,000 miles. BTW, I have a second BMW with an N52 and at 17 years and 122,000 miles the trifecta of N52 leaks have not appeared.

I'll point to the European Tesla 2014 Model S that reportedly has been driven 1.2M miles. It has had fourteen (14) motor replacements and four (4) battery replacements. The manual transmission in my E90 went 426,000 miles on 100,000 mile oil changes. Its just good engineering.

Hey, maybe your E90 and the N52 is better than my old E36 3 series and my Z3. Both had to have rebuilt engines around 150K & 160K, and the E36s were notorious for troublesome VANOS.

Please don't take my comments as an attack on you, BMW, or anything else. I'm just saying let's not pretend like those miles are all maintenance free and trouble free, because they're simply not.

As for that Model S, I agree. Those early Model S's were known to develop coolant leaks internal of the traction motor which would cause premature failure. Similarly, E46s are known to develop subframe cracks. And Gen IV Chevy engines are known to have Displacement on Demand issues (specifically with the DoD lifters).

Now, back on topic: MECHANICALLY, the Slate appears to be really simple. ASSUMING the motor is properly cooled, and that the battery is properly heated & cooled, there's not much that can go wrong. The motor is brushless, the steering rack is electronic, etc. It SHOULD be a relatively trouble and maintenance free platform, outside of standard suspension wear components.

 

[E90400K]

Hey, maybe your E90 and the N52 is better than my old E36 3 series and my Z3. Both had to have rebuilt engines around 150K & 160K, and the E36s were notorious for troublesome VANOS.

Please don't take my comments as an attack on you, BMW, or anything else. I'm just saying let's not pretend like those miles are all maintenance free and trouble free, because they're simply not.

As for that Model S, I agree. Those early Model S's were known to develop coolant leaks internal of the traction motor which would cause premature failure. Similarly, E46s are known to develop subframe cracks. And Gen IV Chevy engines are known to have Displacement on Demand issues (specifically with the DoD lifters).

Now, back on topic: MECHANICALLY, the Slate appears to be really simple. ASSUMING the motor is properly cooled, and that the battery is properly heated & cooled, there's not much that can go wrong. The motor is brushless, the steering rack is electronic, etc. It SHOULD be a relatively trouble and maintenance free platform, outside of standard suspension wear components.

I never said the ICEV miles were maintenance free. I originally commented that more moving parts doesn't necessarily mean less reliability. The actual moving (rotating) parts of an ICEV drivetrain rarely fail when the vehicle is correctly maintained. Lots of people jumped on my case about that statement, bringing in manufacturing defects and such - LOL.

I can't speak to your BMW experiences, but I've had 5 BMWs from the E30 to the E90. I have a Z3 1.9L (M44) that's the 200,000 mile car, and my Z4 is basically an E46. I owned an E46 330i Cabrio for about 30-months, which I brought off a friend at the 100,000 mile mark. I drove it to 135,000 miles, it had a similar maintenace history as any of my other BMWs that I bought new (or used, the Z4 at 23,000 miles).

I agree with you. On paper the Slate should be relatively maintenance free. It all depends on how good the engineering is. I look forward to buying mine. But I've never really had a bad experience owning an ICEV. EV do run at lower operating temperatures, about 90 deg. F less from my research, that doesn't mean ICEV are not engineered to run at 220+ deg. F. I know I'll be dead long before my Slate will run out of miles and heat cycles.