hate to see the inside after a 100k miles
hate to see the inside after a 100k miles
StuckAgainSteve
Well-Known Member
0W-20 isn't a problem. If it didn't boil so easily and you never shut the engine down, plain bearings would be perfectly fine with water rather than oil. Once an engine is running the journals big-ends etc. are kept apart from each other by the hydrodynamic wedge formed by the relative motion of the parts - how good the oil is as a lubricant is then irrelevant. The lubricative properties of the oil are really only a concern at the top of the stroke where the oil film can get burned away and as the nose of the cam reaches the follower - that's when the fluid "wedge" spills away and film strength becomes a concern - and of course during start up where there is metal to metal contact. Roller bearings wouldn't be so tolerant of running in water!
Modern oil isn't actually that great as a lubricant, a large part of the makeup is detergents (which offer nothing for lubrication - quite the opposite), viscosity enhancers (ditto) and chemical potions designed to suspend small particles in the oil rather than let them settle to make sludge. Meaning that over time your oil becomes an abrasive solution. Lastly there little or no zinc (damages cats) the best last line of defence if metal to metal contact does occur. Oil of 50+ years ago would be far, far better as a lubricant - but you'd end up with oil sludge which would kill the engine in no time.
The reason for the above is extended change intervals. The chemical stability of the oil is important to protect seals. Oil filters are designed NOT to filter too efficiently or they'll become clogged over 20K miles - so small particles bypass the filter and are suspended in the oil. If you want your engine to last - change the oil regularly - regardless of the ridiculous modern intervals stated - they can only get away with those intervals because modern engines are so good.
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0W-20 isn't a problem. If it didn't boil so easily and you never shut the engine down, plain bearings would be perfectly fine with water rather than oil. Once an engine is running the journals big-ends etc. are kept apart from each other by the hydrodynamic wedge formed by the relative motion of the parts - how good the oil is as a lubricant is then irrelevant. The lubricative properties of the oil are really only a concern at the top of the stroke where the oil film can get burned away and as the nose of the cam reaches the follower - that's when the fluid "wedge" spills away and film strength becomes a concern - and of course during start up where there is metal to metal contact. Roller bearings wouldn't be so tolerant of running in water!
Modern oil isn't actually that great as a lubricant, a large part of the makeup is detergents (which offer nothing for lubrication - quite the opposite), viscosity enhancers (ditto) and chemical potions designed to suspend small particles in the oil rather than let them settle to make sludge. Meaning that over time your oil becomes an abrasive solution. Lastly there little or no zinc (damages cats) the best last line of defence if metal to metal contact does occur. Oil of 50+ years ago would be far, far better as a lubricant - but you'd end up with oil sludge which would kill the engine in no time.
The reason for the above is extended change intervals. The chemical stability of the oil is important to protect seals. Oil filters are designed NOT to filter too efficiently or they'll become clogged over 20K miles - so small particles bypass the filter and are suspended in the oil. If you want your engine to last - change the oil regularly - regardless of the ridiculous modern intervals stated - they can only get away with those intervals because modern engines are so good.
hope you are changing oil & filter every 5-6k miles
StuckAgainSteve
Well-Known Member
Always have done on every car I've ever owned - never had an engine wear out on me yet.
StuckAgainSteve
Well-Known Member
Is that a typo or did you really say 1,000 miles!? When an oil company I worked for did a massive project to research others' oil before embarking on a fully synth project of its own - pretty much every brand of oil was toast (viscosity wise) by about 4,000 miles - except one - Mobil 1 which stood head and shoulders above the rest. Our oil, by the time we finished, was another also ran which didn't stand out (in lab tests) but we claimed all sorts as all the companies do. I think 1,000m changes are an overkill for crap oil - let alone Mobil 1 - I hope you get it free!
norseman
Well-Known Member
I find modern engines amazing in their lack of oil consumption. Our (non-LR) daily has a 2litre petrol that has now done 132k & will use maybe half a litre in it's average 10k per year.
I'm glad I re-opened this thread, there's been lots of interesting posts as a result.
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brianp38dse
Well-Known Member
It is making some very good reading.
As i said before modern materials with matched coefficients of expansion enable tighter tolerances.
220k miles on a Ford diesel leaks not a drop, or use any between oil/filter changes every 6k miles. 4-5 changes a year
i'm not on about rangies btw, just generally.
current vw recommends 12month or 12k or 24/18k longlife
Datatek
Well-Known Member
I stick to 6K intervals on diesels. The manufacturers don't want the cars to last and they don't on 12/24K changes.
as long as they last enough. they'll do 25-300k like that and by that point the vehicles falling apart due to rust or needs everything rebuilt.
even with good quality cars i'd say you get about 10 years before everything needs replaced. i've only got time to maintain the defender
if it's a classic or something you cherish.. fair enough. but for a runabout. meh.. scrap it
rover v8 die cos of poor oil..they die cos its changed to late..
and yes every 1000miles for me..however i run stupid power out of my v8's and the oil gets a trashing.(but every car/bike i owned i always changed every 1000, but then the engines have cost alot..).gearbox oil gets changed every 1000 too..that comes out like water even when cold!(lt85)
and yes every 1000miles for me..however i run stupid power out of my v8's and the oil gets a trashing.(but every car/bike i owned i always changed every 1000, but then the engines have cost alot..).gearbox oil gets changed every 1000 too..that comes out like water even when cold!(lt85)
StuckAgainSteve
Well-Known Member
Other than extra heat soak - oil doesn't know or care about power. 1,000 mile oil changes are just utterly barmy. You will not see any difference with 5,000 mile changes - particularly if you're running Mobil 1. Gearboxes care about torque - a tuned engine tends to make power further up the rev range so the torque output is the same - or less. The only exception to this is chipped up turbo diesels which can create silly amounts of torque - that breaks gearboxes and oil ain't gonna save you.
ranger1942
Member
I swear by Castrol GTX, its now 10-40. Europarts normally have it in stock. Early V8's don't like modern oils, i started using it many years ago before i lost my hair !!!
albany
Member
Anyone got a link to the Halfords/Comma Classic specs? i couldn't find any Zinc specs. Seems surprising that's reputedly so low given the purpose it's sold for.
I thought the whole point of branding it Classic (or Racing for the VR1) was that it didn't need to comply to current road specs on ZDDP content.
My 4.6 with modern (Thor) pump specifies 10W/40 for UK temp ranges. I use Comma Eurolite which claims 1200ppm of Zinc and is about £60 for 20 litres. Toss up between wrecking the cats or the cam I reckon. I think cats easier...
I use Comma Classic 20W/50 on my older pushrod cars that used to specify stuff like original Castrol GTX (20W/50) or even straight SAE30 - doing the wrong thing there if the Comma ZDDP is indeed low?
I thought the whole point of branding it Classic (or Racing for the VR1) was that it didn't need to comply to current road specs on ZDDP content.
My 4.6 with modern (Thor) pump specifies 10W/40 for UK temp ranges. I use Comma Eurolite which claims 1200ppm of Zinc and is about £60 for 20 litres. Toss up between wrecking the cats or the cam I reckon. I think cats easier...
I use Comma Classic 20W/50 on my older pushrod cars that used to specify stuff like original Castrol GTX (20W/50) or even straight SAE30 - doing the wrong thing there if the Comma ZDDP is indeed low?
norseman
Well-Known Member
Anyone got a link to the Halfords/Comma Classic specs? i couldn't find any Zinc specs. Seems surprising that's reputedly so low given the purpose it's sold for.
quote]
Comma/Halfrauds Classic has 0.08% of ZDDP according to their tech team.
I was about to change to Valvoline (see my previous post) which has 1200ppm but due to a supply problem I've now bought Millers Classic which contains only slightly less zinc. With my RRC I don't have to worry about damaging cats
