Engine oil : VAG to Fiat backward compatibility?

[Bertilak]

I change my own oil on the Ducato '16 Eu5 pre-Adblue, and on our Skoda Yeti 2.0tdi 2016, Eu6 with Adblue.
The engines are practically identical in format, apart from Adblue bolt on, so:

Anyone know why I shouldn't use the oil for the Yeti, 5W40 ACEA C3, in the Fiat asking for 5W40 ACEA C2 ?
btw - I'm looking for knowledge, not just someone to read an application list to me!

It then becomes worth buying it in 20l cans rather than 5s, and is just simpler all round.

 

[Nixdorfer]

It's a total minefield, us garages used to use one oil for most vehicles. Now there are so many we have one 199L barrel that covers about 70% then about 10 other grades in smaller 20L ones for the others. Even then we have order 5L one offs as we find them.

We have to do it to cover ourselves in case of any problems down the line and voiding any manufacturers warranty

There isn't much difference between C2 and C3 but we sometimes have to buy C2 specific oil. Where some cars can take either.

What I usually do is go on the Tradetec, comma and miller's website and put the reg in. Any oils it specifies on there are approved by the manufacturer. Compare those and you may find one that's suitable for both so you can buy in bulk.

 

[Bertilak]

Thanks for the comprehensive answer, even if I'm not much clearer!

 

[Hettie's Crew]

Not meaning to add complications but shouldn’t both of those vehicles be 5w-30. In which case you could use Fuchs Titan which is C2/C3.

 

[Silver-Fox]

I bought some oil a couple of days ago, it was specified for two different manufacturers on the tub.

Can’t remember which oil it was now though and the recycle has been

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[Stealaway]

My Euro 6 Fiat oil speciation is 0-30.
c2/c3 for no apparent reason

 

[Nixdorfer]

If you want to, pm me the reg"s for both vehicles i'll see what grade it says.

 

[Bertilak]

My current thinking is to use Westway's Fiat offering, which being dual C2 and C3 may have a little extra lubricity, at the cost of perhaps 0.5% on economy. That appears to cover both bases, even if it's not been submitted for VAG approval.
https://www.westwayoils.co.uk/collections/engine-oils/products/5w30-dexos-2-synthetic-engine-oil-for-vauxhall-fiat-peugeot-citroen?variant=40600373264572
Having worked in aftermarket engine parts for many years I'm happy to use independent suppliers, especially for their principal product; not always sure about bought-in range additions though ...!

 

[Daffy64]

Personally I wouldn’t scrimp and unless you can find an oil thats approved for both, if you can‘t then don‘t would be my advice.

 

[Bertilak]

Personally I wouldn’t scrimp and unless you can find an oil thats approved for both, if you can‘t then don‘t would be my advice.

Thanks, but is this based on a background in oil analysis or dyno testing, or just the result of successful marketing campaigns?

We know some engines did need special oil (the VW PD engine springs to mind, because of the extreme pressure their cam driven injectors put on the cam), and some do it to help 30,000 miles oil changes or chase the last 0.2% efficiency etc. AFAIK these don't apply in this case.

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[Badknee]

My Euro 6 Fiat oil speciation is 0-30.
c2/c3 for no apparent reason

And it’s bloody expensive I did hear it’s for less smoke on startup, I did think it’s total Bollox.

 

[Daffy64]

Thanks, but is this based on a background in oil analysis or dyno testing, or just the result of successful marketing campaigns?

We know some engines did need special oil (the VW PD engine springs to mind, because of the extreme pressure their cam driven injectors put on the cam), and some do it to help 30,000 miles oil changes or chase the last 0.2% efficiency etc. AFAIK these don't apply in this case.

It’s based on being the technical lead for the UK for one of Europes largest diesel engine manufacturers for over 20 years.

I’ve seen first hand the results of incorrect oils being used and carried out field based (potentially destructive) testing as part of the fault elimination/product improvement process.

In the simplest of terms an when an oil stops providing benefit, it becomes ‘dead’, this is usually when it becomes acidic so a good indicator of an oil is to compare it’s acidity to its alkalinity - without giving anything away we ran a number of engines within a single fleet without changing the oil, these were very similar in their makeup with slightly different ways of reaching the emission standard but essentially the same engine.

Type 1 had dead oil at around 80k km, Type 2 hadn’t really degraded at double that mileage when we lost our bottle and changed it but the fact was that the oil could have stayed much longer and these were engines that an average mechanic would have said were the same, although they did run different oils.

Oh and don’t believe the marketing! If I wanted to find a similar oil suitable for both, then I would speak to the technical dept @ Castrol who are very helpful, if it can be done they will recommend an oil.

The thing is that oil is a very cheap component part of an engine, why would you save a few quid when the consequences if you got it wrong would cost £1,000’s - if you go away from the manufacturers spec at least make an informed decision.

The days of oil being wet and slippy being enough are long gone I’m afraid.

 

[varaizian]

It’s based on being the technical lead for the UK for one of Europes largest diesel engine manufacturers for over 20 years.

I’ve seen first hand the results of incorrect oils being used and carried out field based (potentially destructive) testing as part of the fault elimination/product improvement process.

In the simplest of terms an when an oil stops providing benefit, it becomes ‘dead’, this is usually when it becomes acidic so a good indicator of an oil is to compare it’s acidity to its alkalinity - without giving anything away we ran a number of engines within a single fleet without changing the oil, these were very similar in their makeup with slightly different ways of reaching the emission standard but essentially the same engine.

Type 1 had dead oil at around 80k km, Type 2 hadn’t really degraded at double that mileage when we lost our bottle and changed it but the fact was that the oil could have stayed much longer and these were engines that an average mechanic would have said were the same, although they did run different oils.

Oh and don’t believe the marketing! If I wanted to find a similar oil suitable for both, then I would speak to the technical dept @ Castrol who are very helpful, if it can be done they will recommend an oil.

The thing is that oil is a very cheap component part of an engine, why would you save a few quid when the consequences if you got it wrong would cost £1,000’s - if you go away from the manufacturers spec at least make an informed decision.

The days of oil being wet and slippy being enough are long gone I’m afraid.

Excellent response. Thanks for taking the time.

 

[Garfields]

Put the wrong oil in a Ford engine with a "wet" cam belt and you will kill it.
No idea why ford came up with the idea? really are work of the devil
Sorry not relevant to the OPs original post.

 

[the1andonly]

This has got me thinking about my own situation, but I think it relevant to point out (as previous) that VW504, 507 and euro5 ducato is 5W30 not 5W40. My situation is 2 VAG cars requiring 504,507 5W30 and a Ducato euro6 0W30 Fiat 955535DS1/GS1 currrently using Fuchs for duc@£43 5l or
Westway £80 for 20l of vw504,507 for the fabia CACYC and UP!
Westway £83 for 20l of FIAT Spec
fuchs titan £120-140 20l still got 10l left.
intreaging info is the VW badged bottles of oil is now supplied by Fuchs.
Likely to remain a user of fuchs for duc but anyone use WEstway, Ive got 2 cars to change next month.

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[Silver-Fox]

It’s based on being the technical lead for the UK for one of Europes largest diesel engine manufacturers for over 20 years.

I’ve seen first hand the results of incorrect oils being used and carried out field based (potentially destructive) testing as part of the fault elimination/product improvement process.

In the simplest of terms an when an oil stops providing benefit, it becomes ‘dead’, this is usually when it becomes acidic so a good indicator of an oil is to compare it’s acidity to its alkalinity - without giving anything away we ran a number of engines within a single fleet without changing the oil, these were very similar in their makeup with slightly different ways of reaching the emission standard but essentially the same engine.

Type 1 had dead oil at around 80k km, Type 2 hadn’t really degraded at double that mileage when we lost our bottle and changed it but the fact was that the oil could have stayed much longer and these were engines that an average mechanic would have said were the same, although they did run different oils.

Oh and don’t believe the marketing! If I wanted to find a similar oil suitable for both, then I would speak to the technical dept @ Castrol who are very helpful, if it can be done they will recommend an oil.

The thing is that oil is a very cheap component part of an engine, why would you save a few quid when the consequences if you got it wrong would cost £1,000’s - if you go away from the manufacturers spec at least make an informed decision.

The days of oil being wet and slippy being enough are long gone I’m afraid.

Having read your post can I take it providing an oil is to the approved specifications of any given manufacturer it’s good to go.

Personally I’ve never understood why a vehicle owner would buy an oil that has a vehicle manufacturers name on it as we know they don’t refine oils.

Happy to be corrected if I’m barking up the wrong tree.

 

[Bertilak]

It’s based on being the technical lead for the UK for one of Europes largest diesel engine manufacturers for over 20 years.

I’ve seen first hand the results of incorrect oils being used and carried out field based (potentially destructive) testing as part of the fault elimination/product improvement process.

In the simplest of terms an when an oil stops providing benefit, it becomes ‘dead’, this is usually when it becomes acidic so a good indicator of an oil is to compare it’s acidity to its alkalinity - without giving anything away we ran a number of engines within a single fleet without changing the oil, these were very similar in their makeup with slightly different ways of reaching the emission standard but essentially the same engine.

Type 1 had dead oil at around 80k km, Type 2 hadn’t really degraded at double that mileage when we lost our bottle and changed it but the fact was that the oil could have stayed much longer and these were engines that an average mechanic would have said were the same, although they did run different oils.

Oh and don’t believe the marketing! If I wanted to find a similar oil suitable for both, then I would speak to the technical dept @ Castrol who are very helpful, if it can be done they will recommend an oil.

The thing is that oil is a very cheap component part of an engine, why would you save a few quid when the consequences if you got it wrong would cost £1,000’s - if you go away from the manufacturers spec at least make an informed decision.

The days of oil being wet and slippy being enough are long gone I’m afraid.

Thank you for qualifying your advice: you clearly are in the business; on the internet you never know the expertise of your correspondents...
The whole point of the thread is to gather views to make the decision.
I did also ask Westway, as my proposed supplier; but being relatively tiny simply repeated the "match the manufacturers approval" line, without any particular technical knowledge.

Your comment about the right oil exceeding 160000km (c100k miles) is fascinating. I take it these tests used the same oil, and same block, with different "piping" and parameters?

Personally I've been more of the "don't pay for long life oil, but do change it at the correct shorter interval" view, thus it's not total scrimping, just minimising the extra spend.
I wonder if the recommended long 30K+ mile oil change is more due to minimising cost of ownership for a first user doing 100-150k, to help the buying choice. They may even hope the vehicle dies soon after, as that would require a new sale.
Maybe I am overly cynical, and perhaps I'm old-fashioned playing safe with more frequent changes.
We hear the ambulance services run Ducatos to 400K, but I've also heard they maybe on their third engine, even with A1 servicing; though possibly a hard life.
Owner users, as on the forum, maybe more interested in longevity too; especially those like myself with a conversion done to a clean 100K van, and used for more than just moho forays.
A totally different scenario is for engines that require new oil every year, irrespective of mileage. I realise it can potentially degrade / oxidise from exposure to air, but some motorhome's annual mileages hardly justify extra long-life oil!

Thus there are different user cases that the factories tend to ignore, just to keep the warranties simple and safe, and possibly service depts at optimum. Hence my seeking non-factory advice, and intelligent replies as yours: Thank you.

 

[Daffy64]

Having read your post can I take it providing an oil is to the approved specifications of any given manufacturer it’s good to go.

Personally I’ve never understood why a vehicle owner would buy an oil that has a vehicle manufacturers name on it as we know they don’t refine oils.

Happy to be corrected if I’m barking up the wrong tree.

Exactly, a manufacturers branded oil will be ok but theres an extra margin to be made so price pressures come to play - best buy from the oil co but as long as the oil is approved to the manufacturers std then you’ll be fine, similarly you might find an oil that meets the spec but isn’t approved - just take some proper technical advice from a reputable oil manufacturer if you want to go off piste and you wont go far wrong.

Manufacturers approval is expensive as hoops have to be jumped through as the manufacturer effectively warrants the oil (or the damage it can do) so it could be that an oil does everything it needs to do but isn’t approved as the business case for the oil company doesn‘t stack up - more approvals equals a smaller share of sales.

 

[andykim]

Oil is the blood of an engine,I've got an old ford galaxy which will run on hydraulic (poss) but I wouldn't put crap into the heart of a £70.000 motorhome (fiat based)

 

[Daffy64]

Your comment about the right oil exceeding 160000km (c100k miles) is fascinating. I take it these tests used the same oil, and same block, with different "piping" and parameters?

Basically the same engine meeting the same emission std but a slightly different way of getting there, it turned out some issues with one were oil related, in that it was degrading faster than it should - temperature has a huge impact on oil lif.

Personally I've been more of the "don't pay for long life oil, but do change it at the correct shorter interval" view, thus it's not total scrimping, just minimising the extra spend.
I wonder if the recommended long 30K+ mile oil change is more due to minimising cost of ownership for a first user doing 100-150k, to help the buying choice. They may even hope the vehicle dies soon after, as that would require a new sale.
Maybe I am overly cynical, and perhaps I'm old-fashioned playing safe with more frequent changes.
We hear the ambulance services run Ducatos to 400K, but I've also heard they maybe on their third engine, even with A1 servicing; though possibly a hard life.
Owner users, as on the forum, maybe more interested in longevity too; especially those like myself with a conversion done to a clean 100K van, and used for more than just moho forays.
A totally different scenario is for engines that require new oil every year, irrespective of mileage. I realise it can potentially degrade / oxidise from exposure to air, but some motorhome's annual mileages hardly justify extra long-life oil!

Thus there are different user cases that the factories tend to ignore, just to keep the warranties simple and safe, and possibly service depts at optimum. Hence my seeking non-factory advice, and intelligent replies as yours: Thank you.

I’m not really having much success quoting but

• I’m also in the change it early camp.
• Extended oil drains are a sales argumenter - advances in oil have made this possible and it reduces the cost of ownership and downtime so is a positive sales argument - common sense would have it changed out earlier.
• In commercial vehicles where 120k+ km is now common in certain operations its thought that a good proportion of the oil is changed anyway through the need to top up, you’ll find that these engines are designed to use a little oil.
• Oils do have a life but saying that 2 years is nothing as long as the engine gets to full operating temp regularly to draw the condensation out, when a Motorhome is being used it generally works hard so I wouldn’t worry.

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[Silver-Fox]

Exactly, a manufacturers branded oil will be ok but theres an extra margin to be made so price pressures come to play - best buy from the oil co but as long as the oil is approved to the manufacturers std then you’ll be fine, similarly you might find an oil that meets the spec but isn’t approved - just take some proper technical advice from a reputable oil manufacturer if you want to go off piste and you wont go far wrong.

Manufacturers approval is expensive as hoops have to be jumped through as the manufacturer effectively warrants the oil (or the damage it can do) so it could be that an oil does everything it needs to do but isn’t approved as the business case for the oil company doesn‘t stack up - more approvals equals a smaller share of sales.

Thanks for that.

Let’s just say I’ve never been a buyer of manufacturer seller of oils.
Margins are too high for me

I’m happy to buy a known brand supplier of oil to the manufacturers spec.