Engine Reliability

[Roker]

It would be reasonable to assume that a hybrid would out last a none Hybrid because it is not running half the time, or is this allowed for in the design and it's not as hardy

[Don Mac]

I think it's a bit more complicated than that. Consider how often the hybrid engine is stopping & starting (hence the unusual grade of oil).

I'm not an engineer/mechanic, so I don't have a qualified opinion, but it seems to me that a well engineered ICE could outlast a poorly built hybrid and vice versa.

[flash22]

There are prius out there with 500k+ miles on the clock. Look after it, give it decent oil changes with good quality products

https://www.torquenews.com/1083/driver-1-million-driven-prius-miles-owner-300000-mile-toyota-prius-shares-high-mileage-secrets

 

[Derek.w]

Its not the engine that will kill your car if serviced to Toyota standards including HV Battery service but other factors like rust or traffic accident where its a write-off.

[Cyker]

TBH the 'unusual' oil is mainly because of the tighter engine tolerances modern manufacturing methods have allowed them to build to; It's not a requirement for the stop-start, although it does reduce parasitic losses through friction/drag and the easier flow means it'll get to where it needs to go a bit faster.

At first glance it does seem intuitive that the hybrid drive train would be less reliable - There are more things to go wrong, and as mentioned the constant stop-starting of the engine seems like it would be detrimental to its long term reliability.

Despite this however, the Toyota hybrid drivetrain has consistently scored up the top-end of reliability surveys, and even routinely beats most EVs, despite EVs supposedly being the most reliable due to their lack of mechanicals.

In reality, because the engine is designed to stop and start all the time, it doesn't incur any additional wear from that, and because the electric and ICE are both supporting each other, neither gets stressed anywhere near as much as standalone EV and ICE drivetrains, which have to do all the work all the time.

The point where engines accumulate the most wear is when they're first switched on in the morning due to oil having drained away overnight, and that brief period where the protective oil film isn't fully there to protect the wearing surfaces, esp. when the engine is still cold but gets revved.

The hybrid engines have an easier time of it, as when the engine is started initially, the electric motors provide most of the propulsion and the engine is isolated from any heavy load until it finishes its startup routine, which it uses to circulate oil with minimal load - It gets kept at a low lightly-loaded RPM until it's good and ready. Contrast with standalone engines which, even when cold, will still experience a lot of varying RPM and load in the morning, as they are revved to avoid stalling when moving off, or to make a gap etc.

The hybrids also don't need to rev as high when cruising - They will under acceleration, albeit supported by the electric motors at higher levels of acceleration, but when cruising they can drop their revs to lower and more efficient levels, whereas standalone ICE generally have a set rpm they have to run at for that speed, and is often higher unless they have a lot of gears and enough torque at lower rpms.

But yeah, the short story is hybrids drivetrains will usually outlast equivalent standalone petrol engines and at least match diesel engines for longevity.

[TonyHSD]

Here an interesting video inside Toyota hybrid engine. 

 

[Cyker]

Aaaand that's why you want to give your car regular quality oil changes!  

A good lesson - Even Toyota engines won't be reliable if you don't maintain them!  

But wow that dipstick tube...!  

[Don Mac]

20 hours ago, Cyker said:

... (loads of explanation)

But yeah, the short story is hybrids drivetrains will usually outlast equivalent standalone petrol engines and at least match diesel engines for longevity.

Thanks Cyker, that makes a lot of sense.

Follow up question - does anyone have experience of noticing a difference in a Toyota hybrid once it has been through the "running in" period?

[TonyHSD]

7 minutes ago, Don Mac said:

Thanks Cyker, that makes a lot of sense.

Follow up question - does anyone have experience of noticing a difference in a Toyota hybrid once it has been through the "running in" period?

I had few Priuses from brand new and few at high miles , plus my own Auris done 200k + miles myself only and tbh almost no difference at all. 
Engine and drive train in general sounds and perform exactly the same. Hybrid Battery gets tired and I can notice it, now I know the symptoms of ageing Battery, efficiency though still unaffected, at least for my driving needs. Currently at 60mpg. 

[Cyker]

Yeah I didn't notice much difference from it 'running in' either - Maybe a slight up-tick in mpg, but that could just as easily be slight optimizations in my driving style as I got used to how the car and drive train operate.

 

[YarisHybrid2016]

There will be an improvement over time in MPG as things loosen up slightly as they bed-in and wear.

My Gen.3 (when driven sensibly) gives its best fuel economy now, at 100k miles. It has always been excellent, but it gets "easier" to get high MPG as time goes on.

In the first 20k of its life, it was obviously tight. The day I drove it off the lot it was obviously new, vs. the demonstrator they had - it didn't want to go anywhere.

[AisinW]

From the start, hybrid engine is more efficient than non hybrid because of the Atkinson cycle priority. Non hybrid can have both Atkinson and Otto depends on the demands

As for reliability, they are equal just depends on which engine model. The 1.8L pre 2015 in non hybrid has less head gasket failures. Some engines has tendency consumes more engine oil especially with low tension rings designs.

So using 0w-20 or 0w-16 is necessary to reduce the oil consumption because thicker oil is harder to be scrap back by low tension piston rings and finer cross hatch cylinder wall pattern. 

There is a reasons we should use 0w-xx in newer engines not just for fuel efficiency but by design too. 

[Cyker]

Does that really help? My Mk2 used 0w20 and that definitely didn't help with its oil consumption!

I always thought the main reason for the thinner oils is lower friction/fluid-drag and tighter tolerances that thicker oils can't easily flow through.

[Derek.w]

I use to use 0w30 on a MK2 2014 reg.

[Derek.w]

On 8/28/2023 at 6:33 PM, Don Mac said:

Thanks Cyker, that makes a lot of sense.

Follow up question - does anyone have experience of noticing a difference in a Toyota hybrid once it has been through the "running in" period?

Running in please pass that was a long time ago on todays cars its not required.

[AisinW]

3 hours ago, Cyker said:

Does that really help? My Mk2 used 0w20 and that definitely didn't help with its oil consumption!

I always thought the main reason for the thinner oils is lower friction/fluid-drag and tighter tolerances that thicker oils can't easily flow through.

I think that is normal if you have the pre 2015 1.8L engine. If you have post 2015 engine, they rarely consume oil unless someone neglected it.

[DAF XF]

As an outsider to hybrids looking in - I see a lot of folk talking about changing oil at 5,000 or 7,000 mile intervals. Beng used to 20,000 in a diesel (which takes me about 8 to 12 months) it seems so vastly different. Leaving aside for one minute the view that high mileage intervals are a sales tactic that will cause issues in later ownership when the manufacturer doesn't have to worry about warranty claims... am I correct in thinking it's lower mileage intervals because (a) it's petrol and (b) a hybrid is by its nature more likely to be intermittent and therefore the oil has a harder life? Curious as once my diesel gives up ill be looking at Toyota hybrids. 

[Don Mac]

11 hours ago, Derek.w said:

Running in please pass that was a long time ago on todays cars its not required.

Putting out a sign has gone, but I'm afraid that Toyota disagree with you about running in...

 

[Yugguy1970]

It's never bad to take it easy with a new engine and even with a hybrid don't use full acceleration until the engine is warm.

[TonyHSD]

That’s correct. 
Same recommendation are in my book from 2010. 
What people means by no running in is that after these first 1000 miles there is no need for any service like oil changes for example., and after that there won’t be any noticeable difference in driving behaviour or fuel consumption. 
I had started as first ever driver on few brand new  Priuses and at the same time I was driving older one and absolutely no difference between. Yes after the first 100k miles the engine looses up a bit and becomes nicer to drive and gives that feeling for extra punch but in reality fuel consumption, drivability are all the same. 
For oil changes no need to stress yourself guys. 10000 miles aren’t any high mileage these days to worry about. Anything above  that may cause you trouble but stick with 12 months or max 10k miles and use only quality engine oil by the spec required and you will be fine.
Most drivers won’t cover that mileage within the 12 months period anyway, and those who drives a lot will change a couple of times per year so all good here.
The problems starts when owners neglect oil change intervals mileage or time and skip on change oil because they don’t drive much and think it’s ok . 
Examples low mileage cars 3,4 years old some never even visit a garage to get serviced at all., others when visit a dealer , the mechanics does nothing on the cars and take the parts for themselves to resale on eBay or to keep for their cars and this is how the things are usually starting to go downhill. 
Other factors that may cause you an engine issues in a future is when wrong type of oil been used.
You can change the oil any 3-5k miles but if you use the wrong type , viscosity etc your engine will get cooked during work even at these low miles and you gonna get trouble again. 

 

[Red_Corolla]

21 hours ago, DAF XF said:

As an outsider to hybrids looking in - I see a lot of folk talking about changing oil at 5,000 or 7,000 mile intervals. Beng used to 20,000 in a diesel (which takes me about 8 to 12 months) it seems so vastly different. Leaving aside for one minute the view that high mileage intervals are a sales tactic that will cause issues in later ownership when the manufacturer doesn't have to worry about warranty claims... am I correct in thinking it's lower mileage intervals because (a) it's petrol and (b) a hybrid is by its nature more likely to be intermittent and therefore the oil has a harder life? Curious as once my diesel gives up ill be looking at Toyota hybrids. 

I can only offer an opinion rather than any facts or hard evidence, but I think it's more to do with Toyota's approach to maintenance schedules relative to other manufacturers rather than the type of fuel or technology employed.

One of the biggest reasons for Toyota's reliability reputation is simply that they are honest with their customers about what it takes to make a vehicle last long-term because their focus is on brand reputation, whereas others are more concentrated on simply making sure the product can outlast the warranty in most cases and promoting future sales. A number of people in the aftermarket trade argue, based on experience, that 20k oil changes are not a good long-term maintenance strategy for any vehicle, diesel or petrol, despite the quality of modern lubricants and the assurance from the manufacturer that it's perfectly acceptable.

[RJ414i]

The works Ford Transit which I picked up new (67 reg) with delivery mileage on it as a 2 year or 36k miles oil change interval on it. So you could buy a 4 year old 72k mile example which has a "full service history" which has had 1 oil change at just under 72k miles!

It has a 6k mile change, which is annual.

[Derek.w]

12 hours ago, Don Mac said:

Putting out a sign has gone, but I'm afraid that Toyota disagree with you about running in...

 

You just have to drive sensibly and dont thrash!.

[Cyker]

Yeah, just a bit of common sense driving and it'll be fine.

I mean, with all engines, you're supposed to keep the revs and engine load down until it reaches operating temperature anyway, so it's just an extension of that.

22 hours ago, DAF XF said:

As an outsider to hybrids looking in - I see a lot of folk talking about changing oil at 5,000 or 7,000 mile intervals. Beng used to 20,000 in a diesel (which takes me about 8 to 12 months) it seems so vastly different. Leaving aside for one minute the view that high mileage intervals are a sales tactic that will cause issues in later ownership when the manufacturer doesn't have to worry about warranty claims... am I correct in thinking it's lower mileage intervals because (a) it's petrol and (b) a hybrid is by its nature more likely to be intermittent and therefore the oil has a harder life? Curious as once my diesel gives up ill be looking at Toyota hybrids. 

TBH, it's not just a hybrid thing - even with my diesels I'd make sure it was serviced around 10k miles annually. I personally think 10k/1 year is the absolute minimum interval any car should be serviced for longevity.

Oil is the key to long engine life - Toyotas are especially sensitive to it because they use timing chains, and the key to the health of the timing chain is regular good quality oil changes.

You may get a bit more leeway with diesel, as diesel and carbon in the oil still provides some lubrication, but as petrol gets into the oil it reduces the lubricity of the oil, and it also makes it increasingly acidic over time, so you do not want to leave it in there long term!

 

[Derek.w]

14 hours ago, Don Mac said:

Putting out a sign has gone, but I'm afraid that Toyota disagree with you about running in...

 

Years ago you have a sticker in your rear window I bet you dont have a sticker in Now saying RUNNING IN PLEASE PASS.

So its not a problem now you dont hear of engines seizing up when new because a component in it was extra tight but still able to move.