Used hybrid - what to think of?

[Saxmaniac]

I'm probably over the top with this and people who stick at 10k oil changes are probably fine. I have wondered whether the fact that the engine doesn't run all the time might be harder on the oil. An engine running at a constant load continually and fully warmed up all the time should have ideal conditions? I'm no expert so others may know far more than me!

[Catlover]

23 minutes ago, Saxmaniac said:

I'm probably over the top with this and people who stick at 10k oil changes are probably fine. I have wondered whether the fact that the engine doesn't run all the time might be harder on the oil. An engine running at a constant load continually and fully warmed up all the time should have ideal conditions? I'm no expert so others may know far more than me!

You probably overthinking, an engine uner no load ie stationary is less wear then an engine under load.

I put my trust in Toyota engineers, whose background with hybrids goes back 20+ years, that they wont let the engine temperature drop beyond pre determined/set limits.

[Gray86]

1 hour ago, Catlover said:

You probably overthinking, an engine uner no load ie stationary is less wear then an engine under load.

I put my trust in Toyota engineers, whose background with hybrids goes back 20+ years, that they wont let the engine temperature drop beyond pre determined/set limits.

^THIS. 
 

the fact there are loads of Prius Hybrids with over 100k miles with just normal servicing proves the point. 
 

when I had my Golf R, I did do 6monthly interim oil changes initially, however that car was 300bhp (150bhp/ litre) and got driven quite hard at times. 

[TonyHSD]

10000 miles it’s absolutely exact point for an oil change even though at around 5 k miles the oil gets a bit dirty, let say it just start collecting the deposits inside the engine and store them in it at molecular level, black particles so small goes through an oil filter paper, all good here however the oil at this point at around 6k miles starts loosing its lubrications properties a bit, nothing crucial that can lead to immediate damage but what you can notice is a bit of more noise when under acceleration and little bit less power, plus the engine gets quickly to its operating temperature. at this moment if the car burns oil or oil has evaporated a bit, all hybrids does it especially 3 gen set up, they store a bit of oil in the intake manifold, some design things, anyway.,  It is a good idea to add some new oil or oil additives, this will help the oil remains in its best condition and help protect the engine for the rest of its life inside up to the 10k miles or 12 moths period . 
What happens if you skip the service: 

The engine oil had thinned due to some fuel getting into it and many cycles of heat up and cooling down, too many dirt particles are trapped in too, then it loose lube properties and the ability to keep the carbon deposits inside the oil and with the time these dirt particles will start to build up on the metal parts, limiting oil flow, engine will gain higher temperatures due to a lack of proper lubrication and cooling, the oil will start to evaporate at higher rate and the remaining will become black dirt (grease like) similar to crude oil, this will cover the entire engine inside, can even stop any lubrication and your engine will eventually seize up and die. 3 plus years of keeping your oil and driving regularly the car will enter this saga and another year or two and the worst is imminent. 

[APS]

4 hours ago, Saxmaniac said:

I'm probably over the top with this and people who stick at 10k oil changes are probably fine. I have wondered whether the fact that the engine doesn't run all the time might be harder on the oil. An engine running at a constant load continually and fully warmed up all the time should have ideal conditions? I'm no expert so others may know far more than me!

You're not alone in your reasoning and it's not wrong. However, this is something that was more of an issue in "them olden days".  Oils are much better now and tolerances within the engine are smaller. The oils are thin enough that they provide good lubrication when cold (I think new HSD engines come with 0w16). While the small tolerances in bearings keep the oil film more clingy. So, the engine just needs to be kept at a reasonable temperature to ensure better compression and full combustion for efficiency. I think (someone who knows feel free to correct me), Toyota keep the coolant at around 50 degrees minimum. So, you should not see huge swings in oil temperature. High engine temperatures accelerates oil degradation more than stopping and starting. 

Of course, you will do no harm replacing the oil more frequently. It will keep the engine nice and clean and maintain those tight tolerances for longer. I know taxi drivers with high mileage prius engines move over to 5w30. Maybe more because it's cheaper 🙂

[Timmon]

The Hybrid ICE has it's oil changed at 10K, as many non Hybrids do. But the ICE will not have been running for 10K, some of that mileage will have been run on electric only.  The other thing I consider is that the ICE fires up on a cold morning, and you can drive to the main road with revs at 1 to 2K, with the electric motor being used to power the wheels, the ICE is just warming up and charging the Battery. So, compared to a non hybrid, there is a good chance the ICE will warm up the oil nicely, before you reach the main road and can put your foot down. All these things must decrease wear on the ICE.

[Saxmaniac]

All interesting stuff! I go back to old BMC mini and similar engines and 3000 mile changes! I'd been following all the posts on Prius Chat to get an idea of known faults, solutions and best maintenance but I also realise that a lot of stuff on there is just based on opinion rather than hard facts. One main reason for extra oil changes (according to them) is to prevent gumming up of oil control rings and huge oil consumption usually past 100k miles. The Gen 3 Prius is prone to this pre 2015 when pistons and rings were redesigned. Not much info after that. (This is all second hand info as I don't really know a lot, just trying to learn a bit and grateful to people out there who know more!)

Hope the original poster doesn't mind this diversion to his thread btw

[testbil]

Just now, Saxmaniac said:

All interesting stuff! I go back to old BMC mini and similar engines and 3000 mile changes! I'd been following all the posts on Prius Chat to get an idea of known faults, solutions and best maintenance but I also realise that a lot of stuff on there is just based on opinion rather than hard facts. One main reason for extra oil changes (according to them) is to prevent gumming up of oil control rings and huge oil consumption usually past 100k miles. The Gen 3 Prius is prone to this pre 2015 when pistons and rings were redesigned. Not much info after that. (This is all second hand info as I don't really know a lot, just trying to learn a bit and grateful to people out there who know more!)

Hope the original poster doesn't mind this diversion to his thread btw

I don't mind at, interesting discussion! 

[TonyHSD]

8 minutes ago, Saxmaniac said:

All interesting stuff! I go back to old BMC mini and similar engines and 3000 mile changes! I'd been following all the posts on Prius Chat to get an idea of known faults, solutions and best maintenance but I also realise that a lot of stuff on there is just based on opinion rather than hard facts. One main reason for extra oil changes (according to them) is to prevent gumming up of oil control rings and huge oil consumption usually past 100k miles. The Gen 3 Prius is prone to this pre 2015 when pistons and rings were redesigned. Not much info after that. (This is all second hand info as I don't really know a lot, just trying to learn a bit and grateful to people out there who know more!)

Hope the original poster doesn't mind this diversion to his thread btw

That’s exactly what happens when oil changes are skipped or extended by far and or when different type of oil like 5w30 been used. I have two old Auris hybrid that does not consume oil at all, always been serviced with 0w20. One of the cars been taken from London to the end of Europe - Black Sea coast and back, 6000 miles journey within 3 weeks time driven through Eu motorways in massive heat wave was around 37-40C° , no oil consumption at all, the oil in was petronas and I have been using this oil ever since, 5 changes a year. However when buying a used car even only 3 years old the risk of getting a car with damage made already is always there, sometimes you can notice on inspection prior to purchase, but sometimes you can not. In USA many 3 gen Prius suffer piston rings problems due to the fact they had used wrong oil type or did not service on time, also in hot climates the oil change intervals can be shortened to help keep engine internals clean. Btw this Toyota hybrids motor oil stays clean for longest of all cars that I been working on, therefore when checking the oil make sure looks bright if not means oil is old and needs change, and buying from main dealership doesn’t necessarily mean you are getting best possible used car, but reassuring you can come back and complain and ask for help if something is wrong. 

[APS]

I've seen intermittent oil consumption on the CT (same drive train as 3rd Gen Prius). We do the occasional blast through Europe when we do about 850 miles / 1300 km in a day. Once I experienced that the oil level had dropped from full at the start to just over minimum at the end of the trip. The car has always been serviced by Lexus and I always check to make sure they put in 0w20 - which they do. That said, it has never happened again though and it has now done about 110k and still runs like new.

[APS]

8 hours ago, Saxmaniac said:

All interesting stuff! I go back to old BMC mini and similar engines and 3000 mile changes!

Ah, the A series! That brings back memories. You did want to change the oil frequently on those as the gearbox sat in the sump shedding metal shavings and kind sharing it with the rest of the engine. If not properly looked after those engines would often look like they'd ingested a small desert. Sorry, I'm straying off topic. I'll stop right here. 

[FROSTYBALLS]

On 12/21/2020 at 6:02 PM, APS said:

I think new HSD engines come with 0w16

The latest  hybrids (Corolla, C-HR, Prius, Rav4) and the Aygo use 0W-16, and the new Yaris hybrid uses 0W-8

[Gerg]

11 hours ago, Saxmaniac said:

is to prevent gumming up of oil control rings and huge oil consumption usually past 100k miles.

This is a PriusChat thread below that you may have already seen but, just in case you haven't - there are some very good photographs of a thorough engine strip down.  Plenty of close-ups of piston rings and pistons. 

The thread is very long - but then this lock-down could be around for some months yet!  If you do read it, perhaps avoid reading it all at once.

https://priuschat.com/threads/blown-head-gasket-rebuild-297k.179092/e

Also, with regards the frequent engine stop/starts, I read somewhere that,when performing a warm start, the Toyota hybrid engine is turned through two rotations with no ignition/injection, and then starts on just two cylinders initially.  I think this was to prevent a sudden torque reaction and general smoothness, but this must also help get the oil moving again after the engine has been stopped. 

But I understand your point about a properly lubricated, steadily-running hot engine suffering barely any wear - hydrodynamic lubrication rules!

 

[Parts-King]

Modern oils are used for a variety of reasons, they are more stable than "Standard" mineral based cheapo oils, they lower emissions, are more fuel efficient, they also allow for less oil to be used in the engine, reducing weight, less upfront purchase costs, less oil to dispose of in the environment etc. So I would always recommend you pay the least you can for better quality oils, a 5W 30 mineral oil will work well, but not as well as a synthetic based oil with a lower viscosity 

[APS]

1 hour ago, Parts-King said:

I would always recommend you pay the least you can for better quality oils, a 5W 30 mineral oil will work well, but not as well as a synthetic based oil with a lower viscosity 

Agree. That said, I would have thought that any 5w (or lower) graded oil will be *at least* part synthetic, n'est-ce pas?

[Parts-King]

1 minute ago, APS said:

Agree. That said, I would have thought that any 5w (or lower) graded oil will be *at least* part synthetic, n'est-ce pas?

Never take anything for granted, you would "hope" it was part synthetic, nothing is guaranteed in this life. Why not go for a branded "fully synthetic" version? It is far better, but slightly more expensive