WHICH OIL IS BEST??
- Thread starter floyd 1.8 turbo
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Turbo Lag FTW
Hate those none insured you know who types
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Ive been using Castrol Edge for last 6 months and have only needed to top it off this month, maybe used quarter a litre in 5000 miles which I find rather good considering the price of this oil.
Mobil; 1 is too thin,presuming its the 0w-40.The best all round viscosity for road use is either a 10w-40 fully synthetic or 5w-40.10w-40 is a little more difficult to get hold of in decent form,Amsoil,redline are the best grade 'A' synthetic stock oil's at the moment.None of the high street brands use grade A base stocks!!!!
Another good oil which i rate highly is millers,Very good base stock although not as high a grade as the above mentioned but is what i use in every day road vehicles,and never had any issues whith sludging etc.
Another good oil which i rate highly is millers,Very good base stock although not as high a grade as the above mentioned but is what i use in every day road vehicles,and never had any issues whith sludging etc.
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i tend to use comma fully synth 5w40
its not the best fully synth oil, but i change it every 4-5k miles anyway as i dont believe its good for the engine for any oil to be in there after it goes black, and it usually turns around 4-5k miles, and the comma stuff is pretty cheap from my motorfactors
I realise that proper synthetic PAO/Ester based oils are better, but in a 160k mile engine that uses a litre of the stuff every 2-3k its just not worth the cost.
its worth noting that the only difference between 0w40, 5w40 and 10w40 in terms of viscosity is its thickness when COLD. They will all have identical viscosity once at operating temperature so saying 0w40 is too thin is complete crap.
The thinner the oil when cold then better protection it provides on startup, and even a 0w40 is still thicker when cold than it is once its warmed up, so its cant possibly be too thin compared to a 10w40
its not the best fully synth oil, but i change it every 4-5k miles anyway as i dont believe its good for the engine for any oil to be in there after it goes black, and it usually turns around 4-5k miles, and the comma stuff is pretty cheap from my motorfactors
I realise that proper synthetic PAO/Ester based oils are better, but in a 160k mile engine that uses a litre of the stuff every 2-3k its just not worth the cost.
its worth noting that the only difference between 0w40, 5w40 and 10w40 in terms of viscosity is its thickness when COLD. They will all have identical viscosity once at operating temperature so saying 0w40 is too thin is complete crap.
The thinner the oil when cold then better protection it provides on startup, and even a 0w40 is still thicker when cold than it is once its warmed up, so its cant possibly be too thin compared to a 10w40
your turbo bearings take the biggest kicking when they first spin up and the oil is cool and when the engine is turned off before allowing the oild to cool down to a reasonable temperature.
0w40 is specifically designed to combat this and recommended for turbo engines
0w40 is specifically designed to combat this and recommended for turbo engines
Hi,thanks for the 'correction' aragorn,with out going into it too much it depends greatly on your geographic position as to whether the 0 winter rating would be too thin or not.In this country it is simply too thin and a complete waste of your money given the fact a 10w rating provides instant viscosity and flow.
The more apart the numbers the more VI additives are needed,these have a flip side..they shear causing sludging and thinning of the oil causing wear and damge to the components hence the move to 5w-30 for some manufacturers etc(apart from the economy aspect etc).
The simple fact is you end up paying more for a thinner oil than a slightly thicker oil.It is a common misconseption that oil is thinner at higher temps,when in fact the dorment thickener in the oil thickens the oil to give the second multigrade number ie a 40.Oil may seem physically thinner but is only more viscous,two entirely different ball games.
Hope this helps
The more apart the numbers the more VI additives are needed,these have a flip side..they shear causing sludging and thinning of the oil causing wear and damge to the components hence the move to 5w-30 for some manufacturers etc(apart from the economy aspect etc).
The simple fact is you end up paying more for a thinner oil than a slightly thicker oil.It is a common misconseption that oil is thinner at higher temps,when in fact the dorment thickener in the oil thickens the oil to give the second multigrade number ie a 40.Oil may seem physically thinner but is only more viscous,two entirely different ball games.
Hope this helps
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Oh sure i realise all these additives break down over time and reduce the performance. If i had a shiney expensive engine i would be more inclined to use top spec oils etc. I was mainly trying to point out that a cheaper oil changed more regularly is for the most part going to be the best value on a high mileage engine.
I can do oil changes every 4-5k using comma 5w40 "synthetic" for £15-20ish or spend £40+ on a PAO/Ester based fully synth like the silkoline pro-s mentioned above and run it for 8k.
I feel for an engine like mine that has high miles, is not in a particularly high state of tune, and uses relatively a lot of oil, the cheaper oil changed more often works out better for me. I dont believe my engine would benefit in any way from using the more expensive oil for longer periods.
If the choice was between the cheap comma oil for 8k and the silkoline for 8k then clearly the silkoline is probably going to be the better choice as it will be performing closer to its specification by the time it gets changed.
Its worth pointing out that oil IS thinner at high temps even with the additives etc.
An oil with a rating of (anything)W40 must have a viscosity rating of between 12.5 and 16Cst's at 100 degC as thats an SAE requirement.
If we look up the datasheet for a silkolene 10w40 oil we find that its viscosity at 100degC is 14.7 Cst and at 40c is 99.0 Cst, ie thinner at 100c than it is at 40
if we look up the datasheet for a castrol edge 0w40 oil which is "too thin" we find its viscosity at 100c is 13.5Cst and at 40c its 79Cst, ie still much much thicker when cold than once its hot. but the drop from 99cst to 79cst when cold gives the engine better cold start protection.
I can do oil changes every 4-5k using comma 5w40 "synthetic" for £15-20ish or spend £40+ on a PAO/Ester based fully synth like the silkoline pro-s mentioned above and run it for 8k.
I feel for an engine like mine that has high miles, is not in a particularly high state of tune, and uses relatively a lot of oil, the cheaper oil changed more often works out better for me. I dont believe my engine would benefit in any way from using the more expensive oil for longer periods.
If the choice was between the cheap comma oil for 8k and the silkoline for 8k then clearly the silkoline is probably going to be the better choice as it will be performing closer to its specification by the time it gets changed.
Its worth pointing out that oil IS thinner at high temps even with the additives etc.
An oil with a rating of (anything)W40 must have a viscosity rating of between 12.5 and 16Cst's at 100 degC as thats an SAE requirement.
If we look up the datasheet for a silkolene 10w40 oil we find that its viscosity at 100degC is 14.7 Cst and at 40c is 99.0 Cst, ie thinner at 100c than it is at 40
if we look up the datasheet for a castrol edge 0w40 oil which is "too thin" we find its viscosity at 100c is 13.5Cst and at 40c its 79Cst, ie still much much thicker when cold than once its hot. but the drop from 99cst to 79cst when cold gives the engine better cold start protection.
i was not disputing the fact a cheaper oil changed more often would be any less preferential than an expensive oil changed with a standard schedule,more that the oil is too thin for the geographic location.
tests have shown you get no benefit using a 0w rating to aid cold start protection than you would with a 10w(in the uk),but with this in mind i was merely stating you could save money and be no worse off by using a 10w... or 5w...as we don't 'need' a very thin oil because we are'nt in very very cold climates.
i do as you do,slightly cheaper(in comparisson to say redline)millers oil changed at a more regular interval as it costs me next to nothing.
tests have shown you get no benefit using a 0w rating to aid cold start protection than you would with a 10w(in the uk),but with this in mind i was merely stating you could save money and be no worse off by using a 10w... or 5w...as we don't 'need' a very thin oil because we are'nt in very very cold climates.
i do as you do,slightly cheaper(in comparisson to say redline)millers oil changed at a more regular interval as it costs me next to nothing.
have had it on a Fuch's synthetic for a year or so now, haven't had any issues.
oils oil untill something goes wrong haha, though being in Northern Australia cold starts are not an issue.
oils oil untill something goes wrong haha, though being in Northern Australia cold starts are not an issue.
