Technical The Great Engine Oil Debate

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Technical The Great Engine Oil Debate

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On another forum that I subscribe to, a post in which oil was mentioned as an incidental, a huge debate was aroused about the merits of modern sythetic multigrades (typically 10W60) and "classic" mineral oils (typically 20W50).
The argument has been well lubricated on both sides and having started with no strong views I am now reasonably persuaded that the modern stuff would be best. I may even experiment when I have completed another 5000 miles, but at around £50 for 5 litres, maybe not.:eek:

Has anyone got first hand experience of synthetics? It may have cropped up as topic previously.
 
A great debate indeed and I can only go by what I have read , been told or experience. It is well documented that a well maintained engine can go on for 100,000 miles without any major work. Without oil the engine would last 5 mins and with a poorly maintained engine a limited life. I am quite sure that a well maintained engine will be fine on the 20W50 under normal conditions. However I am told that synthetics act as a cleaning agent inside the engine as well as lubricating. This has been proved to me when I have rebuilt engines where the components have been cleaned as much as I can get them. Then on start up I have used something like a cheap 10W40 fully synthetic and run the engine under no load for about 30 to 40 mins. Get everything nice and hot with a few throttle blips then drain the oil. I was shocked when it came out black as it got to the bits you can't get to. I then switched to using 10W60 after reading that it is more robust at the higher temperatures that the air cooled engines run at. It made sense to me and as both of my engines are modified to some degree I think it gives a little bit more assurance. As for cost when you spend about £1200 to £1600 on the basic lump just in parts then an extra few quid is worthwhile I feel plus if you plan ahead and keep an eye on the Halfords site you can get some special offers so I have about 15 litres in my garage :)
Now a very learned friend also told me that fully synthetic is not good when bedding in new piston rings and mineral is best and that the bedding in mostly takes place on the first few strokes of the engine on start up. So it seems that a good squirt of mineral on the rings on assembly would take care of that if it is correct.
 
If you wait for a discount offer on euro car parts (they happen often) you can pick up good quality 10w60 for a more reasonable price. I just looked up the email of my last order and it was...

521770981 @ 34.99 GBP
Castrol Edge 10W-60 With Titanium FST Fully Synthetic 4Ltr

The have free delivery, but not sure if that would still apply to Nairn.

As far as engine oils go it's lovely stuff.

cheers, Steve
 
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The have free delivery, but not sure if that would still apply to Nairn.

As far as engine oils go it's lovely stuff.

cheers, Steve

Free delivery to Nairn? (he scoffs):) You would think that Scotland was an independent country! A lot of suppliers in England won't consider delivery to us and when they do they charge rates that mean they know you won't bother. I sense another topic coming on.:mad:

I've never thought of an oil being "lovely", even for oil.:) But I will try it. Thanks.
 
My only worry is that with no oil filter, is the centrifugal crud catcher up to the job, with a detergent oil.

May be worth a try, clean out the drive pulley, change oil to synthetic and run for a few thousand miles, then check the crud catcher.


H A
 
The 'crud catcher' as HA so eloquently put it, is remarkably efficient--take an engine apart that hasn't had an oil change for some time and just see how much muck is in the filter--and it is remarkably hard. I was advised by Tony castle-Millar to use 10/60 oil in my (modified) 126 engine--it gives much better protection at high engine temperature--and when your pride and joy has probably cost you a 4 figure bill, the little extra that the top-spec oil costs is negligible. All oil, fully synthetic, part synthetic etc. is basically the black stuff that comes out of the ground--it is what the oil company does to it and what they add to it that makes the difference. Ask any top engine builder to name a reason for classic engines producing noticeably more power (and often more reliably at the same time) than when they were new, and they will mention modern lubricants as a prime reason--in fact some classic engines whose lubrication systems were marginal when originally designed/built have been transformed by modern lubricant characteristics.
If you have a standard engine, in the UK (where ambient temperature is not normally a problem), I would have thought a good 20/50 oil will suffice, but if you have a tuned engine and/or do a lot of mileage, than I would recommend that a 10/60 is used
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I agree with Tom 100%. 20W/50 will be fine in our standard untuned 500 lumps.

Probably because I use the Halfords stuff as well.

I saw the debate you started Peter on the other website and was going to reply but there were clearly a few people who seemed to know an awful lot more than me and possibly have done too much research on the Internet.

Someone described Halfords oil as rubbish, it's clearly not made by them, almost certainly by a major oil company and then tells people continuously to do their research. Maybe he should find out who makes the Halfords stuff first before making such a bold statement?

There are a lot of old school knowledgeable guys on that site. But they are very much into originality in the finest detail.

Our door handle angle debates pale into insignificance compared to some of the debates on there.:D
 
Love the strap round the seats, is that holding the floor together?

I would say door handle in your picture is about 10 degrees too far clockwise.;)

H A
 
I know the angle is right but I still maintain that it could do with being one more notch down. If you had a lady with long nails using the door handle regularly she is going to scratch the paint to pieces. One notch lower she is going to be clawing the door card to shreds and it's cheaper to replace a door card!!!!!:D Or to be less sexist what if a cat got locked in the car and was trying to get out!!!!:D

Oh no what I have reignited.:rolleyes:

BTW..... That steering wheel locks in good condition, no cracks etc....under all that patina. Aka oily hand prints.
 
The 'crud catcher' as HA so eloquently put it, is remarkably efficient--take an engine apart that hasn't had an oil change for some time and just see how much muck is in the filter--and it is remarkably hard. I was advised by Tony castle-Millar to use 10/60 oil in my (modified) 126 engine--it gives much better protection at high engine temperature--and when your pride and joy has probably cost you a 4 figure bill, the little extra that the top-spec oil costs is negligible. All oil, fully synthetic, part synthetic etc. is basically the black stuff that comes out of the ground--it is what the oil company does to it and what they add to it that makes the difference. Ask any top engine builder to name a reason for classic engines producing noticeably more power (and often more reliably at the same time) than when they were new, and they will mention modern lubricants as a prime reason--in fact some classic engines whose lubrication systems were marginal when originally designed/built have been transformed by modern lubricant characteristics.
If you have a standard engine, in the UK (where ambient temperature is not normally a problem), I would have thought a good 20/50 oil will suffice, but if you have a tuned engine and/or do a lot of mileage, than I would recommend that a 10/60 is used
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Couldn't agree more- 20w50 is ideal in a standard engine for low speed pottering around at moderate temperatures, I have used the 10W60 for the last 10 years- a 5 litre pack is enough for 2 oil changes so the cost difference over 2 years of driving is negligible and well worth it in my opinion...
 
Have been looking at the Castrol website, and this is their view:

"CLASSIC ENGINE OILS
WHY USE CLASSIC OILS ?

The formulations required for modern vehicles are very different from those needed for older vehicles. Oils for modern engines comply with the latest API ratings of SN/CF and specific ACEA and OEM specifications dealing with fuel efficiency, extended drain intervals and aftermarket exhaust treatment systems and are specifically designed for the modern engine needs.

A classic car engine however, can have the opposite characteristics with cork/graphite/rope seals, low pressure gear driven oil pumps, larger oil galleries with greater dependence on "splash" and "cling" lubrication, lower revving with larger machine clearances. Such a widely different engine design can demand a totally different lubricant and the Castrol Classic Oils range offers formulations for older vehicles that have been specially blended for the work they have to do.

Inadequate detergent can result in gums and lacquers clinging to the hotter engine components, and blocking oil galleries – But, too much detergent can cause a build-up of metallic ash in the combustion chambers and piston crowns . In older engines with traditionally high oil consumption, this can cause detonation and pinking.

In older engines where the carbon has built up over a number of years detergents can have a scouring effect, causing the carbon to flake off, blocking up oil galleries and spray jets. High levels of detergent can also "wash" traces of carbon from seals and gaskets, revealing oil leaks where the carbon itself is creating a seal.

Insufficient anti-oxidant and the oil can quickly thicken during high temperature motoring, with large amounts of carbon, gum and varnish clogging oil galleries, filters and piston rings.

Anti-wear additives are added to ensure that if the oil film between moving parts breaks down prematurely, metal to metal contact and irreparable engine damage is prevented.

Engine internals can become pitted with corrosion and rust from acids and water vapour formed during combustion. With the correct corrosion inhibitors, the components are well protected.

Special dispersant additives prevent soot, wear metals and the by-products of combustion settling out in the sump and other areas of the engine, and forming a thick sludge that can block filters and oil ways.

If there is inadequate pour point depressant the oil ceases to flow at low temperatures, with excessive strain on the oil pump or in certain cases, oil starvation on start-up causing complete failure of the lubrication system."

I will stick with the older stuff, unless I build a hot engine from scratch.

Have also heard that fully synthetic can be more prone to leaking, and can drop the oil pressure a few pounds.

I personally am a great fan of fully synthetic, my VW T5 uses it with a 20,000 mile service interval, but I still change it at 10,000:)

H A
 
Sorry if I dumbed it down,

"Centrifugal oil particulate separating sediment collector":)

H A

I decided to fit a 'spin on filter' for the same reason, but, that gave a lot of other problems - money spent on quality oil is never wasted - unless your engine leaks somewhat???

Ian.
 
From time to time I do a bit more research about engine oils (I ask Gary Google of course :D). My latest thought is that it might make sense to use motorcycle oils. Even more important than the viscosity of the oil, it seems that that the quantity of the elusive ZDDP additives is crucial to slowing down wear in fast-revving, air-cooled engines with flat-tappets.

There are motorcycle oils which can't be rated under the systems for passenger vehicles because the different needs of their engines,which include wet-clutches, mean that they still have to use large quantities of the zinc and potassium based compounds to enhance "slipperiness" instead of those annoying alternative catalyst "friendly" compounds which don't give the same protection to our camshafts and followers.

I became worried because at the latest oil-change I used the recommended, inexpensive Shell Helix 15w40 from my supplier but then realised that it is one of the modern types of oil.

So I may start another experiment with Mobil 15w50 at the next change.:rolleyes:

https://www.engineoildirect.co.uk/1...qmOeMyEwkPLsyIQaq81ziVsneiclmHRBoCph4QAvD_BwE
 
I shall stick my 'ape eth worth' into this debate. I have a fully well tuned 652cc 126 engine in the back of my 500, which I will admit, I drive fairly 'Italian'. I therefore use Millers 'Nanno-drive' 10/60 oil. This is a top class, and fairly expensive, modern oil. I am full agreement with Ian (bleeding knuckles) that money spent on quality oil is never wasted. For the standard 500engine, I would advocate the use of one of the modern, 'Classic' 20/50 oils---Castrol, Millers, Morris, Duckhams (now available again). Oil is such a relatively small cost in regard to the rest of the cost of an engine, that skimping on engine oil is a very false economy. Peter's idea of using a 15/50 sounds interesting--but don't forget he has a 652cc engine which gets a LOT of use.
 
From time to time I do a bit more research about engine oils (I ask Gary Google of course :D). My latest thought is that it might make sense to use motorcycle oils. Even more important than the viscosity of the oil, it seems that that the quantity of the elusive ZDDP additives is crucial to slowing down wear in fast-revving, air-cooled engines with flat-tappets.

There are motorcycle oils which can't be rated under the systems for passenger vehicles because the different needs of their engines,which include wet-clutches, mean that they still have to use large quantities of the zinc and potassium based compounds to enhance "slipperiness" instead of those annoying alternative catalyst "friendly" compounds which don't give the same protection to our camshafts and followers.

I became worried because at the latest oil-change I used the recommended, inexpensive Shell Helix 15w40 from my supplier but then realised that it is one of the modern types of oil.

So I may start another experiment with Mobil 15w50 at the next change.:rolleyes:

https://www.engineoildirect.co.uk/1...qmOeMyEwkPLsyIQaq81ziVsneiclmHRBoCph4QAvD_BwE

I’m confused. Why does it say oil grade 15w-50 under additional info but on tech info is says 10w-40?
 
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