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.

 

[E90400K]

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

But most of the EV is the same as ICEV and benefits from that 100 years. The electric motor predates the ICE. But I do agree, EV should have a higher reliability based on the need for less maintenance.

 

[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. That longevity comes at a not insubstantial preventative maintenance cost. BMW has some of the neediest engines I've experienced from a preventative maintenance standpoint. 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 their gasket rubber sucks, but it does. Same with the ~100k limited-life electric water pump and thermostat. The whole experience was best summed up by 'close, yet so far'. Just because an engines is capable of going extremely high mileage with enough diligence and expense, doesn't make for a great argument.

Subaru fanbois can also brag that their EJ25's are 300k reliable... 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.

 

[E90400K]

Let's be clear here though. That longevity comes at a not insubstantial preventative maintenance cost. BMW has some of the neediest engines I've experienced from a preventative maintenance standpoint. 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 their gasket rubber sucks, but it does. Same with the ~100k limited-life electric water pump and thermostat. The whole experience was best summed up by 'close, yet so far'. Just because an engines is capable of going extremely high mileage with enough diligence and expense, doesn't make for a great argument.

Subaru fanbois can also brag that their EJ25's are 300k reliable... It just needs to be fed a steady diet of head gaskets.

I think it makes for a great argument. 400,000 on an ICE is a testament to argue more moving parts doesn't necessarily mean less reliability and longevity.

There is a Model S in Europe that reportedly has hit over 1 M miles. IIRC the car went through five (5) motor replacements and three (3) battery replacements. I'll put my E90 up to that record any time. My driveline was original.

 

[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.