Oil for turbo cars?

[spynish]

Hi all,

Have been reading many posts here and in SC about best oil type...  s:? :? s:?  
So which oil viscosity would you recommend for a turbo 2 bearing in mind here the temps vary from 5 to 40º C (usually not more than 35º in summer)  s:?: :?: s:?:  
Should I get something thicker than 40?

Thanks a lot!  s:D s:D  

P.S: Did a search but still confused...

[Slacey]

Get in touch with the guys at Opie oils -  w www.opieoils.co.uk w  as their advice is excellent, what he doesn't know about oil isn't worth knowing!

[aaronjb]

Based on things the guys at Opie have said before, I'd go for something like a 5W-40 fully synthetic from Motul or Silkolene, possibly a 10W-50 but I doubt they'd advise anything heavier.

[spynish]

Thanks guys!

What about ESSO oil, is it good? Or leave it and just use Mobil1?
There is a ESSO 5w 40 in a local shop that is supposed to be for performance engines and costs 36 euros/ 4 liters.
Can't fine references of this oil, though...  s:roll: :roll: s:roll:  

Any advice?

Thanks again!

[aaronjb]

Never even knew Esso made oil.. I mean - engine oil for cars  s;) s;)

I'd go for the Mobil 1 given the choice of those two, it's excellent oil in general.

[markiii]

esso used to be reccomended and sold by Merc dealers so it can't be that bad.

[aaronjb]

esso used to be reccomended and sold by Merc dealers so it can't be that bad.

True.. then again - don't Toyota put Magnatec in our cars?

[markiii]

fair point, shoot me now for that logic  s:oops: :oops: s:oops:

[Anonymous]

Be careful when looking at Mobil1 as there are 2 grades the 0-40 is just toooooooooooooooooooooooooooooooo thin for a turbo car.

DO NOT try and save money on oil. decent oil and regular changes will give your car engine an easy and long life.

Personnally I use 76 oils and it gets changes every 1000 miles. Its only the same a an extra tank of fuel or so. But then again I do track days etc and that is harder on the engine.

My 2p worth

[Tem]

So which oil viscosity would you recommend for a turbo 2 bearing in mind here the temps vary from 5 to 40º C  s:?: :?: s:?:  

Castrol TWS 10W-60

Over here pretty much everyone with serious engine uses that, even the guys rallying with WRC cars . There's just no option  s:lol: :lol: s:lol:

Having said that, there are tons of options that suffice, but if you don't feel like trying, just get that. Definitely not -40 grade though  s:? :? s:?

[aaronjb]

Castrol RS 10W-60

Over here pretty much everyone with serious engine uses that, even the guys rallying with WRC cars . There's just no option  s:lol: :lol: s:lol:

The guys at Opie oils don't have a very good opinion of that oil compared to the other grades in the range (well to be exact, it's replacement 'Edge Sport'), as apparently it's not a true fully synth whereas the others are (so I was told when I asked over on IMOC)..

I'm intrigued why you say not a 40 grade too? Personally I don't think a -40 is too thin in a modern car, including turbocharged ones..

[Tem]

it's not a true fully synth

Is true fully synth necessarily better?

I'm intrigued why you say not a 40 grade too? Personally I don't think a -40 is too thin in a modern car, including turbocharged ones..

Just my opinion  s8) s8)  I wouldn't use -40 even in NA car if it sees high temps and load. Of course it'll be just fine if you take it easy during the hottest days or have means to control the oil temp and keep it cool.

[aaronjb]

Is true fully synth necessarily better?

Well, the guys over at Opie tell me it is  s;) s;)  And surely common sense says much the same really - it'll stand up to more abuse by design..

Depends what you're doing with your oil - as you say, WRC cars run RS 10-60.. Then again, how long do they expect an engine to last? (I'm presuming you're talking about privateer WRC spec cars, not race teams where the answer there is obvious - one rally meet or less  s:D s:D )

Just my opinion  s8) s8)  I wouldn't use -40 even in NA car if it sees high temps and load. Of course it'll be just fine if you take it easy during the hottest days or have means to control the oil temp and keep it cool.

Hmm.. I've not seen any problems with the various cars I've run -40's in, including the Z (now that's a hot engine bay  s;) s;) ), granted I've never had a chemical analysis run so all I can go on is colour & consistency when I drain it..

FWIW, Opie recommend 5W-40 for the 3S-GTE in medium-highly modified situations and strenuous use.. not sure what they'd recommend for exceptionally modified engines & track use, though.

[Tem]

Well, the guys over at Opie tell me it is  s;) s;)  And surely common sense says much the same really - it'll stand up to more abuse by design.

I'm not so sure about that  s:? :? s:?

It's true that synth can be made better than mineral in every way. But guess if most brands bother to make the most out of the synth, or are they just trying to maximize their profits and make it pass some standards to get fancy stuff on their cans. I do believe that a good semi synth can be better than some fully synth.

Actually the biggest difference seems to be that fully synth lasts longer. Not really a concern if you change your oil often enough anyway  s8) s8)

Depends what you're doing with your oil - as you say, WRC cars run RS 10-60.. Then again, how long do they expect an engine to last? (I'm presuming you're talking about privateer WRC spec cars, not race teams where the answer there is obvious - one rally meet or less  s:D s:D )

Yeah, I meant private teams, no idea about the factory cars. Most do have a tight budget and they'd rather have the engine last as long as possible  s;) s;)

Hmm.. I've not seen any problems with the various cars I've run -40's in, including the Z (now that's a hot engine bay  s;) s;) ), granted I've never had a chemical analysis run so all I can go on is colour & consistency when I drain it..

I think that's a very hard comparison to make. Who knows if the engine would've been in better shape after 200t miles with better oil?

I've used -40 as well and I can't say I've noticed anything I could blame on it myself. I'm just going by what I've read and wouldn't use -40 in engine that really gets hot  s:? :? s:?

[Tem]

DOH...I got them mixed up  s:oops: :oops: s:oops:  

Went to Castrols site to see if that really is semi synth and seems I mixed RS and TWS. Using the first in my winter beater and the latter in the Spyder  s:? :? s:?

[aaronjb]

Actually the biggest difference seems to be that fully synth lasts longer. Not really a concern if you change your oil often enough anyway  s8) s8)

True - that's the biggest visible difference, for sure.. There were other things that Simon & Guy pointed out, though, that I'm by no means good enough at chemical engineering to understand, let alone quote  s:) s:)

Wonder if we could get them to come on here, actually..

I'm just going by what I've read and wouldn't use -40 in engine that really gets hot  s:? :? s:?

True - I suppose it depends how hot is hot.. er, if you see what I mean  s:) s:)  Since every oil will have a point at which it becomes useless, and too high a weight will leave you with an oil that's too thick to operate properly under 'normal' conditions (i.e. the other 99% of the time for a road car, I imagine).

Likewise, I'm just going by what I've read really - and the guys at Opie seem to consistently recommend lighter weight oils than you'd expect (like 5W-40 over 10W-60 - previously I'd always run 10W-60, btw, in the Nissan)

Anyway, where you live you could probably get away with 0W-0 six months of the year  s;) s;)   s:lol: :lol: s:lol:

[Tem]

Posted at the same time, so check my post above, mixed the letters  s:? :? s:?

(they claim RS is fully synth too though)

[aaronjb]

DOH...I got them mixed up  s:oops: :oops: s:oops:  

Went to Castrols site to see if that really is semi synth and seems I mixed RS and TWS. Using the first in my winter beater and the latter in the Spyder  s:? :? s:?

 s:D s:D

They also (confusingly) seem to have different 'models' in different countries  s:? :? s:?

Case in point - RS seemed to include some of the TWS range over here (at least from what I can guesstimate from specs & anecdotal evidence), but the RS range has now disappeared and been replaced by 'Edge' (RS, I think) and 'Edge Sport' (TWS, I'd guess)

Confused.. I am..  s:D s:D

[edit] Aye - they say Edge & Edge Sport are both fully syn too.. but the guys at Opie mentioned something about synthetic bases, esters and PAO numbers.. it all went a bit over my head, but I tend to believe them (they seem to give impartial advice - and sell pretty much every brand of oil, not necessarily recommending the most expensive stuff, which is usually a good sign  s:) s:) )

[Tem]

RS range has now disappeared and been replaced by 'Edge' (RS, I think) and 'Edge Sport' (TWS, I'd guess)

Maybe only in UK?  s:? :? s:?
 m http://www.castrol.com/castrol/productd ... Id=7000250 m

I just bought RS this friday...could be old stock though, but that site still talks about RS/TWS though.

[aaronjb]

Maybe only in UK?  s:? :? s:?

Aye that's what I meant, sorry  s:) s:)  I went hunting for specs when I bought it, and it does seem that they only rebranded in the UK - that or websites are out of date for all the other countries.

Be nice if they kept it simple for us, wouldn't it  s;) s;)

[spynish]

Hi!

Not much information of ESSO Ultron in English, seems a commercial strategy... ?:roll:
In any case, having compared Mobil 0w40 and ESSO Eltron 5w40 characteristics, seems they are pretty similar (Mobil a bit more viscous), so I'm going to try it.
Thanks for your help mates!  s:wink: :wink: s:wink:

[mph]

Millway suggested using 10W60 and this was later 'confirmed' as the ideal grade by the engineers at TTE.

[oilman]

Some really bad misconceptions here and wrong facts.

Actually thinner oils are better for turbo cars, not the other way around.

WRC teams tend to use sae 30 and 40 oils, The Subaru one uses Motul 300V 5w-40 for example.

Don't use 10w-60 unless the car is seeing very extreme oil temps, by this I mean in excess of 140degC!

Let's get one thing clear, I supply 10w-60 and recommend it where it is appropriate for the engine or the application but conversly I caution against it's misuse!

I have debated this many times on many car forums and I know there are some that do not agree with me however I have never had a reasonable technical explanation why 10w-60 is in fact suitable, it's certainly not mentioned in the handbooks of many modern highly tuned performance cars, with the exception of some Alfa Romeos for "spirited driving" whatever that is meant supposed mean.

Explaining this is diffucult so there may be questions but I'll try my best to explain it in plain English!

Lets look at what oil specs actually mean and particularly the higher number which is in fact the oils SAE number (the "w" number is in fact the cold crank viscosity and measured in a different way) The SAE number is measured by the oils viscosity at 100degC.

Your cars require according to the manufacturers specs, sae 30, 40 and in some cases sae 50.

To attain the relevent sae number the oil has to be at 100degC (no thinner than)

SAE 30 11cst approx
SAE 40 14cst approx
SAE 50 18cst approx

Centistokes (cst) is the measure of a fluid's resistance to flow (viscosity). It is calculated in terms of the time required for a standard quantity of fluid at a certain temperature to flow through a standard orifice. The higher the value, the more viscous the fluid.

As viscosity varies with temperature, the value is meaningless unless accompanied by the temperature at which it is measured. In the case of oils, viscosity is generally reported in centistokes (cst) and usually measured at 40degC and 100degC.

SAE 60 is in fact 24cst viscosity at 100degC!

This is 33% thicker than an sae 50, 70% thicker than an sae 40 and over 100% thicker than an sae 30!

So, what's the problem with this thickness?

Well, this is measured at 100degC and at lower temps (70-90degC) all oils are thicker than at 100degC so the problem is compounded to some extent.

The downsides of such a thick oil (when not specified) are as follows:

Additional friction, heat and wear.
A reduction of BHP at the wheels
Lower fuel consumption

The thicker the oil is the more friction and drag and the more power the engine needs to move it around the engine which inevitably translates to less at the wheels.

So, when do we spec a thicker oil?

Well, you will probably have seen us on occassions recommending a 10w-50 but only in these circumstances.

1. If the car is heavily modded and heat/oil temperatures are excessive.
2. If the car is used on track and heat/oil temperatures are excessive.
3. If it's required by the handbook.

Our criteria for this is based on oil temps as an sae 40 semi-synthetic can handle around 110degC for limited periods whereas a proper synthetic sae 40 can hande 120-130degC for prolonged periods due to its thermal stability.

Once you see more than say 120degC for prolonged periods an sae 50 is adviseable as it is 18cst at 100degC and still 11cst at 130degC! This is in fact the same as an sae 30 at 100degC.

More importantly at 90degC an sae 40 is 15cst, an sae 50 is 20cst and an sae 60 is 30cst!

In a worst case scenario with thick oils (when not required) is that you will experience air entrainment and cavitation inside the bearings at high RPM. Not clever stuff!

I know this is technical stuff but oil is a combination of science and engineering and few people know enough about it to make an informed choice. Just because your mates use it and have had no problems is not a good enough reason to use it, your engine would prefer and benefit from the correct oil.

Cheers
Simon

[aaronjb]

Thanks for stopping by Simon  s:) s:)

[Anonymous]

Thanks for stopping by Simon  s:) s:)

Ditto!
A few more comments: it is generally best to avoid oils with a wide spread in viscosity numbers. 10W60 would use a 10 grade base stock that is fortified with polymer based viscosity stabilizers. These polymers can shear down and reduce the upper grade. Also they can cook in the ring lands and clog them. For many years, diesel motor oils did not come multi-vis because  high operating temps would destroy the stabilizers.
Many synthetic oils do not require viscosity stabilizers if the grade spread is small (usually about 20), but all petroleum oils do.
I owned a MK2 turbo, and I could hear the turbo spool since it was about 1 foot from my right ear. Response was far faster and at lower rpms with 10W30 than with 15W50 (Mobil 1 in both cases). FWIW
Just my 2¢