Engine oil for a turbo

[Alpine]

Hi, I have the 2.4 light pressure turbo.

Any view on what engine oil I should be using? I have been using Castrol 10/40 semi-synthetic, but I did see on Facebook recently someone saying that full synthetic should be used on a turbo, otherwise can damage the turbo.

The handbook isn't clear, as it just says it must meet specification ACEA A3, which Castrol 10/40 semi-synthetic does.

[ITSv40]

The ACEA A3 spec is the most important consideration. I use Shell Helix Ultra 5/40 in mine Fully synthetic. The 5 is better for the VVT pulley than 10.

[Baffler]

Originally Posted by ITSv40

The ACEA A3 spec is the most important consideration. I use Shell Helix Ultra 5/40 in mine Fully synthetic. The 5 is better for the VVT pulley than 10.

As ITSv40 says meeting the SAE or ACEA spec being the most important. A good 10W-40 semi-synthetic is perfectly adequate, as recommended 25 years ago, but it breaks down quicker than a fully synthetic, especially on turbocharged variants, hence why it's recommended to change it more frequently over fully synthetic.

When we had our 2.5T V70 I had Castrol Edge 5W-40 A3/B3 in it as I wanted the best oil for those 20 valves and turbo. It's a bit more expensive, yes, but you'll also have an extended oil change interval over semi-synthetic.

Just be careful when buying modern oils as some may not be correct for your engine. The sales chaps, understandably, are only interested in numbers so you'll need to do your own research prior to purchase. The grade may appear correct/similar but the spec might be very different. When you exceed the spec, here's where it starts to get confusing, your getting into the area of High Temp High Shear and how the oil performs under certain conditions. For example an A3/B3 has a high HTHS value, performs well for frequent start/stops and shorter journeys whereas A5/B5 has a low HTHS value and better suited to prolonged journeys and higher temps. A lot of it is dependent on your driving style and demands on the engine.

Put simply if you meet the A3 spec you'll be fine. Change a semi-synthethic every 6 months and full synthetic every 12 months.

[sdg1970]

Utter rubbish you can only use full-synthetic. I use Castrol GTX 15/40 mineral in my R and change it every 2500-3000 miles.

[Tannaton]

Semi synthetic oils are mostly mineral based with synthetic additives. The problem with mineral oils is they can "cook" in the turbocharger housing after the car is switched off if the turbo is hot - hence the advice to let a engine idle for a few mins before turning off after a run. When the oil cooks, it can leave deposits.

Whilst all sorts of things would have been recommended 20+ years ago - modern oils are much more developed and relatively cheaper.

I would only use a fully synthetic oil, I user Comma X-Tech 5/30 in all my D5's and T5's.

[RollingThunder]

Tannaton has put it quite elequently - which is why I only use fully synthetic oil in a turbocharged engine.

Re the weight of the oil, it depends upon your location (expected weather temperatures) and the condition of the engine. I usually use a 5W winter grade as this allows the engine to crank over more easily in the cold.

I use 5W40 fully synthetic in my 850R, as the ambient temperature has been going from one extreme to the other in recent years - I've seen -12 in winter and +32 in summer, and thats in Yorkshire.

[El Padrino]

Interesting thread and something I've been thinking about doing.

I can't find a fully synthetic 10W-40 that meets ACEA A3 for my 1998 2.3 V70R. Upon searching for a 5W-40 fully synthetic RollingThunder is using in his 850R, I found the Castrol Edge 5W-40 fully synthetic, but the spec only states ACEA C3, so clearly not the right spec for my engine -

https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/046831F405E172F580258973003AB119/$File/WEPP-CPY979.pdf

My Haynes only states SAE 10W-30, 10W-40 or 15W-40 ACEA A3 for turbo engines. So I guess I can't use 5W-40 or is the Haynes out of date now and I can use 5W-40?

Can anyone recommend a fully synthetic 10W/40 that meets ACEA A3?

Many thanks.

[Tannaton]

Originally Posted by El Padrino

Interesting thread and something I've been thinking about doing.

I can't find a fully synthetic 10W-40 that meets ACEA A3 for my 1998 2.3 V70R. Upon searching for a 5W-40 fully synthetic RollingThunder is using in his 850R, I found the Castrol Edge 5W-40 fully synthetic, but the spec only states ACEA C3, so clearly not the right spec for my engine -

https://msdspds.castrol.com/bpglis/FusionPDS.nsf/Files/046831F405E172F580258973003AB119/$File/WEPP-CPY979.pdf

My Haynes only states SAE 10W-30, 10W-40 or 15W-40 ACEA A3 for turbo engines. So I guess I can't use 5W-40 or is the Haynes out of date now and I can use 5W-40?

Can anyone recommend a fully synthetic 10W/40 that meets ACEA A3?

Many thanks.

I'd maybe look again but on the basis of "meets or exceeds".

[El Padrino]

Originally Posted by Tannaton

I'd maybe look again but on the basis of "meets or exceeds".

Thanks Tannaton. So, going on the basis Shell Helix Ultra fully synthentic 5W-40 meets ACEA A3, I would be able to use it? And if the Castrol Edge 5W-40 fully synthetic meets ACEA C3, does the C3 'exceed' A3 and is OK to use? Is that what you mean?

[Tannaton]

Originally Posted by El Padrino

Thanks Tannaton. So, going on the basis Shell Helix Ultra fully synthentic 5W-40 meets ACEA A3, I would be able to use it? And if the Castrol Edge 5W-40 fully synthetic meets ACEA C3, does the C3 'exceed' A3 and is OK to use? Is that what you mean?

I would say so - C3 is more diesel focused though I think. This may help:

https://www.opieoils.co.uk/t-acea-ca...dern%20engines.