Answers From The Oil Expert Part # 2

[oilman]

Hello all,

As a follow on from our last post on questions and answers from John Rowland we now have part 2 for those that crave more ”aoily knowledge”a.

As before some of these topics have been covered but we feel worth the read.

Some oil companies have run advertising campaigns that imply their products have special, unique qualities. Can these adverts be taken seriously?

Yes and no! Generally adverts in magazines are honest, with marketing-speak terms such as ”˜Magnatec’ and ”˜Electrosyntec’ really being code words for esters, which are particularly beneficial in performance engine oils. No manufacturer has any unique ”˜secret’, so it’s all down to providing the best possible blend for the job at the right price, and making it clear that you get what you pay for. I personally think that the importance of shear stability or ”˜stay in grade’ is not stressed enough when quality is talked about.

What is dodgy though is claiming that a mineral based oil with a few percent of modified mineral (”˜hydrocracked’) synthetic is the DB’s and suitable for racing, etc. when it clearly isn’t.

Also, there is endless semantic manoeuvring and lawyer-speak around The Magic Word ’synthetic’.

For instance, a ”˜synthetic’ oil is invariably semi-synthetic (’Ah! We didn’t say it was all synthetic did we?), and, if low priced, invariably the modified mineral type synthetic. It is a sad fact that you get what you pay for, but even so, stick to the reputable UK/European brands, and remember that shipping an oil half way around the world doesn’t automatically make it better than one made in your home town.

As for TV advertising”¦well, does anybody believe it? Due to its huge cost, a TV advertising campaign can significantly raise the cost of specialist items such as oil. Everybody assumes it’s just a few pence per gallon, but it can be pounds per gallon.)

Please can you explain the grading system? What is meant by the weight of an oil? What does 10W/40 mean for example?

Weight means viscosity, or resistance to flow. Water and paraffin flow very easily, so they are low or light viscosity. Golden syrup or 140 gear oil do not come out of the can so easily, so they are high or heavy viscosity.

Especially with oils, temperature is very, very important. An oil which looks ”˜heavy’ at 20C will be very ”˜light’ at 100C. People sometimes say, ”˜I drained the oil when the engine was hot and it ran out like water”¦’ so I say, ”˜Good! It’s supposed to be like that!’

The American Society of Automotive Engineers (SAE) ratings cover cold starts and ”˜up and running’ viscosities. There are two sets of standards, the ”˜Winter’ (W) ratings, and the 100C standard ratings. (”˜W’ does not, repeat not, mean ”˜weight’!)

So a 10W/40 oil has to pass a 10W cold viscosity test at -25C, and a SAE 40 test at 100C. In an oil lab there will be a refrigerated viscosity measuring device for the ”˜W’ tests and another at 100C for the standard SAE tests. There are 6 ”˜W’ ratings from the difficult 0W at -35C to the dead easy 25W at -10C, occasionally used in India for example!

The whole point of these Winter ratings is to assist cold starts, to get the oil circulating quickly, and to avoid power and fuel wasting drag as the engine warms up. Once it is warmed up, the 100C ratings count. There are 5 of these, 20, 30, 40, 50, and 60 although why anybody bothers with 60 in the 21st Century is a mystery to me!

Sorry folks, but I’ve got to get technical. Viscosity is measured in standard units called ”˜Centistokes’, names after a Victorian engineer, Sir George Stokes, who used to time ball bearings as they sank through oil. SAE 30 for example is from 9.3 to 12.5 Centistokes, and SAE 40 follows on at 12.5 to 16.3, although most SAE 40 oils are in the middle at about 14.

Now this is something most don’t realise: engines do not know what grade of oil they’re running on. They’re not clever enough! So an engine filled with 10W/40 will be running on a viscosity of 14 at 100C, but with a sump temperature of 90C its seeing a viscosity of 18, so as far as the engine is concerned it’s running on SAE 50. Likewise, at 110C, it’s down to 11 Centistokes so it ”˜thinks’ it’s on a SAE 30! (Which is preferable.)

The lesson is, do not use power and fuel-wasting thick oils in cool climates. A decent 10W/40 or even thinner is perfectly OK unless you’re running a classic with wide clearances and a slow oil pump.

Radical race cars use 1300 Suzuki Hyabusas and work them very hard. (Didn’t one take the old Nurburgring absolute record at one point?). They use our high-ester 15W/50, but that’s OK because they see oil temps around 130C! (No problem for the oil or the engine, but they do fit special oil seals.) At 130C the true viscosity is 10cSt, so the engine thinks its on a thin SAE 30, which keeps it happy.

What is the best type of oil to use in a road car for general use? Is fully synthetic a waste of money?

Personally I’d go for a shear-stable part ester synthetic, SAE 10W/40 or 5W/40. The ”˜shear-stable’ bit (ie, a decent quality multigrade polymer) is actually more important than the ”˜synthetic’ part!

If strapped, I’d go for a shear-stable mineral based oil rather than a ”˜synthetic’ of dubious stability that’s probably based on modified mineral oil anyway. Unless you’re covering a huge annual mileage, genuine 100% synthetics are probably an extravagance. High mileage long-distance fans can use a light full synthetic and save on fuel and oil changes, and cut overhaul costs if things get to that stage, but more later”¦..

What are the main differences between 2 and 4-stroke oil? Why does 2-stroke oil have to be mixed with fuel?

2-stroke oil has a very short working life, straight in and out, and it gets burnt. The 2-stroke engine doesn’t have a sump full of oil and the bearings are all rollers, so there’s hardly any oil drag, hence no need for multigrades. Long term stability is obviously not a problem!

But, 2-stroke must burn off without leaving any plug-fouling or detonation-initiating deposits. The detergent and anti-wear additives used in 4-stroke oil leave hard white ash behind when they burn, just what you do not need in a 2-stroke. So 2-stroke oils use low-ash detergents and dispersants, and the better types use ester synthetics to act as anti-wear compounds.

With current environmental concerns, smoke is a sensitive issue, so most ”˜road’ 2-stroke oils are now low smoke, which requires yet another type of synthetic base designed to burn off invisibly. For some rather basic but very high-revving air-cooled racing 2-strokes there’s still some sense in using blends with that marvellous anti-seize liquid, castor oil!

Due to crankcase induction and compression, the classical 2-stroke obviously cannot have an oil-filled sump, so the only way to keep an oil film on anything was to add oil to the fuel, or inject oil into the crankcase space where it could mix with the fuel vapour. There are now some engines where the fuel and oil are injected separately, but the oil is still burnt.

How important is it to change oil regularly? What are the implications of failing to do so?

It is only really important to change oil regularly if the engine covers a low annual mileage made up of slow, short runs. This is being cruel to the oil and the engine! The oil, regardless of its quality, gets full of fuel and water vapour, and never gets the chance to evaporate it all off with a long fast run. The consequences are corrosion, ring and bore wear. It is essential to do a change at least once a year, even if the recommended mileage hasn’t been covered. On the other hand, if you eat up the miles on long blasts the engine and its oil will love it, so with a top-quality oil it is OK to cheat a little on oil drain periods.

Do some types of oil (i.e. fully-synthetic) ”˜wear out’ quicker than others? How important are timely oil changes? Can you rely on the frequency suggested by your User Manual?

The type of oil that is likely to give trouble after low mileage is a light viscosity type with poor shear stability, either mineral or modified mineral based. (Such as one of the USA ”˜fuel economy’ oils for lazy car engines that pushed the Japanese OEMs to bring in their own oil spec.) The important thing is the shear stability; the much hyped ”˜synthetic or mineral’ nonsense is a red herring.

The oils that will last the longest are the relatively rare 100% genuine synthetic shear stable types, which will easily stand twice the recommended drain period in a high-mileage high performance engine. (So in the long run they aren’t really so expensive.) Just the thing for those touring fiends who pack up and set of for the Transylvanian Alps as soon as the clocks go forward!

Of course, User Manual drain recommendations are based on a back-covering ”˜worst case’ scenario of low annual mileage on poor quality oil, so they can be regarded as a very safe minimum mileage.

In the past, there used to be trouble with heavy carbon deposits and sludge around the engine with early low-detergent oils, but these days almost any oil with a good API specification will keep everything clean for 10 to 15,000 miles, so that’s the least of your worries.

Does oil have to be warm to do its job properly? Is it important to warm up your engine before using at speed?

Yes, it does have to be at least warm, and preferably hot. Most people except the sort with white finger syndrome find metal at 60C too hot to touch, yet 60C is too cold for oil in an engine that’s going flat-out. The best approach is to use a good 5W/40 or even a 10W/40, and take it easy for the first couple of miles, especially in very cold weather.

For racing, a really good warm-up is essential, except perhaps with special 0W/20 low-drag race oils. The trouble is, oil pumps are very good at pushing oil out at 60PSI, but unfortunately there is only 14PSI (atmospheric pressure) pushing it in! (Even less in Katmandhu.) So it’s easy for an oil pump to pull voids or pockets of vacuum in the oil if it doesn’t flow fast enough into to uptake. This ”˜cavitation’ obviously reduces the amount of oil the pump can deliver.

Also, in high-speed bearings the oil can be too thick to keep up with the high rubbing speeds reached in modern engines so the ”˜wedge’ or hydrodynamic’ effect breaks down. I know it goes against common sense (whatever that is) but the faster a bearing is turning the thinner the oil should be. (A 4cm. diameter main bearing is rubbing its shells at 56 MPH at 12,000RPM! To avoid cavitation the oil need to be less 10cSt or less, which is SAE 30 if the oil happens to be at 100C, or SAE 40 if its at 110C.))

What is the difference between road and racing oils?

The days of incense-like ”˜R’ oils for racing only are past, except for classics. At least as far as 4-strokes are concerned, the best synthetic types are ideal for both race and road use.

With ultra-precise components, high-pressure pumps and high engine RPM there has been a move to special synthetic low cavitation/low drag oils to release more power with no reliability loss. These can be (and are!) used in road cars, but 0W/20 is not mentioned in the user handbooks, so there is always some warranty risk. Honda is perhaps the only exception!

How does a high-performance oil allow the motor to produce more power?

An engine wastes fuel energy in several ways, and most of them are due to the laws of thermodynamics, which is another way of saying you can’t do much about it. But up to 6% of engine output is lost due to oil drag, made up of pumping losses and viscous drag between moving components. The transmission is included in this.

Provided wear and friction are kept down, there are real gains to be made by using a ”˜tough’ but low viscosity oil. Surprisingly, frictional losses are low, down at 3% or less even with conventional oils, so there are few gains to be made here.

I have actually seen this extra power output on the dyno! A very experienced operator in Peterborough who does a lot of test work for Lord Emap used his own year-old Honda Blackbird, with the first run on his favourite 15W/50 high-ester synthetic. 128BHP. Then we changed to a 5W40 high ester synthetic. (So it wasn’t an unfair comparison with B & Q 15W/50!) This time we saw 131.6BHP with a corresponding torque increase. Finally we went to a new (at that time) 0W/20 special synthetic and 134.4BHP appeared! Even the boss was impressed! Later trials in different race and road engines showed this level of improvement was no fluke, so it really does work; and, with the right chemistry to look after the engine and transmission internals, there’s no down side of increased wear.

Why do some engines consume oil? Is this a problem?

Large air-cooled engines or classics with wide piston clearances, or very highly stressed liquid-cooled engines which flex under load, or which use ultra-light pistons with the minimum number of rings are likely to be oil users. There is little that can be done about it. Unfortunately, burnt oil tends to leave hard deposits in the combustion chambers which can initiate pre-ignition, so more frequent top overhauls are usually necessary.

Occasionally, touring engines will use oil for no apparent reason. This is often due to the oil level rising in the crankcase due to air retention, leading to oil loss through the breather. The answer is to move to a lighter grade of oil to improve air release.

If you need to top up your engine oil, how important is it to use exactly the same brand and type?

Not very important at all. Unfortunately, due to ”˜arse covering’ reasons we cannot print this advice on the can! Although officially all manufacturers advise against mixing different makes and grades, in fact there is very little chance of any harm being done, even if one is a mineral 20W/50 and the other is a 5W/30 synthetic. Obviously, avoid this if you can, but do not panic if there’s no other alternative. Just don’t mix 2 stroke and 4-stroke oil!

There are all sorts of additives available which are supposed to improve ordinary oil and reduce friction, improve power output etc. Are they worth a try?

Oil is already a very advanced and deeply researched fluid which does not need any ”˜enhancement’. There is no secret formula out in the backwoods that the mainstream lubricant chemists do not know about; but there are plenty of half-baked ideas and gullible people out there!
These wonder additives are usually 1930s chlorinated paraffins, long obsolete gear oil additives which should have disappeared in the 1950s, but they keep turning up as ”˜Xxtrasuperlube ZX3’ with a mark-up of several thousand percent. They actually corrode engine and transmission internals, so they do far more harm than good.

Others depend upon the total myth that PTFE powder coats engine internals and reduces friction. It doesn’t do anything or the sort. It just blocks the oil filter. The AA tested one of these overpriced PTFE concoctions (”˜Quick 60’ or something) very thoroughly back in the 80s. They stated: ”˜This is an expensive way of coating your oil filter’.

So there we have it, would just like to thank once again John Rowland (R&D Chemist) for taking the time to provide these answers to questions that we are frequently asked.

If you have any further questions, please ask.

Cheers

Guy and the opieoils.co.uk team.

PS. All New Opie Oils website coming soon!

[liquid079]

Thanks for that oilman.

So I'm thinking I need an oil change soon in my 325i, am I wasting my money using fully synthetic oil as I don't race my car, although it has no oil cooler fitted?

Dan

[oilman]

No its not a waste, a good 5w-40 changed every 8-10,000 miles is ideal.

Cheers

Guy.

[liquid079]

Cheers for that I'll cary on using Motul 8100 X-cess 5w-40 then.

[fingerman]

I've used Motul 8100 X-Cess 5w-50 for my previous M50 engined E34's (520 + 525) and now for my M20 E30 and it works a treat

And great service from Guy !

[dannyboy759]

Ive got a 325 and ive always used 10-40 part synthetic, is this right?

[Gwynleym10]

Can someone do an "executive summary" of that please..

[casper8r]

Can someone do an "executive summary" of that please..

Easy!

"It is a sad fact that you get what you pay for, but even so, stick to the reputable UK/European brands, and remember that shipping an oil half way around the world doesn't automatically make it better than one made in your home town. "

[casper8r]

I just read the whole thing and I say - make it a sticky!

[oilman]

Ive got a 325 and ive always used 10-40 part synthetic, is this right?

Yes its fine, 10w-40 semi or next up is a 5w-40 synthetic.

Cheers

Guy.

[Gortour]

I just read the whole thing and I say - make it a sticky!

This and part 1 are now stickies in the Technical Help section.

[maxfield]

Can someone do an "executive summary" of that please..

+1

[Andy335Touring]

Mr Oilman, will my car go faster now it has purple coloured oil(Silkoline) in it ?

(only joking, it was just a suprise today when doing my oil change)

[oilman]

lol, the colour does get noticed.

Oil are clear by nature, so they add pigment usually golden as this is the colour that the customers relate to oil.

In reality I guess you could have it any colour you like.

Cheers

Guy.

[murran]

oilman, i work in a vag specialist garage. just wondering what your opinion is on these "long life oils" we see nower days?
these oils are much more expencive than the normal quantum stuff. and up to 20000 miles in between services just seems rediculous to me.
plus were seeing probs with audi tts vw mk4 golfs audi 2.5 v6 tdi engines that have been on the "longlife shedual" some with under 100000 miles and the cams, followers and tappets are all knackard!! the cam gear looks like itsout of a pinto thats done 200k!!

[oilman]

Interesting one, personally I am not a fan of longlife oils, there is no substitute for good oil with regular changes.

Sadly most car manufacturers are doing this, all german and now the Japs and Italians are following suit.

Cheers

Guy.

[GuyM]

is this engine restorer any good? it's meant to fill in the gaps on the cylinders!
http://www.americantechnology.co.uk/

[oilman]

NO! I have a chemical report on this, its not good reading.

Mail me for a copy of it if you like, sales@opieoils.co.uk

Cheers

Guy.

[Turbo-Brown]

Oilman, can you tell us a bit more about the many additives you see kicking about? A guy at work keeps banging on about the bloody things and I really want something to shut him up once and for all as the "don't you think these additives would already be in the oil if they were worth anything" arguement hasn't worked yet

[oilman]

Any additive in particular he is on about?

Perhaps this will help, it covers most "magic additives"

General Remarks on Chlorinated Additives.

A number of â€Ëaadd-on' additives intended to improve the performance of commercially available automotive lubricants have been marketed in recent years, under such names as â€ËaXxtralube ZX-1', â€ËaMetol FX-1', â€ËaPPL Anti-Friction' and â€ËaActiv-8'.All such products share the following characteristics with â€ËaX-1R Friction Eliminator':-

1) They all contain chlorinated paraffin â€Ëaexteme pressure'(EP) compounds first used in the 1930s in heavily-loaded industrial gearboxes, and in some automotive transmission applications, mainly hypoid gears.

2) They all corrode copper-based alloys at moderate temperatures, easily exceeded in all engine, and most transmission applications.This problem was recognised in the 1930s, and chlorinated compounds were never used in transmissions with bronze bearings or gears. No responsible manufacturer ever suggested using them in engines where their increasing activity at high temperatures could lead to piston ring corrosion and bore glazing. (For the same reason, modern â€Ëahypoid' additives are not used in engines, even though they are much safer than any chlorinated additive.)

3) X-1R Friction Eliminator and its clones are based upon very outdated technology, which was abandoned by responsible lubricant manufacturers for automotive transmission uses in the 1950s. Chlorinated compounds still find applications in metal working, but their use is on the decline because of health and safety considerations.

4) When burnt, chlorinated paraffins produce corrosive hydrochloric acid, and organo-chlorine compounds including the highly poisonous phosgene gas. Apart from these corrosion and health hazards, with petrol engines the deactivation of exhaust catalysts is also a problem.

5) Unfortunately, these additives give spectacular results in simple EP test machines such as the â€ËaFalex'. As a marketing ploy, a demonstration of this type looks impressive to those not aquainted with the above facts. Also attractive is the low cost of chlorinated compounds, allowing profits of several thousand percent to be made.

Cheers

Guy.

[johneiuk]

hey i am just think i normaly use valvoline oil cant remember what it is. all i know its durablend i have been told valvoline is a good oil. is this true and what is your view on this oil

cheers john

[oilman]

Valvoline is ok, average oil and the durablend is a hydrocracked mineral oil, but then it is well priced so with regular changes it will be fine.

Cheers

Guy.

[johneiuk]

many thanks i will keep on using this oil. what grade do you recommemd for a 325is and for a 316i. thank you so much for your help

[oilman]

10w-40 semi cost option, 5w-40 synthetic quality option, brand wise I rate Fuchs, Motul and Silkolene.

CHeers

Guy.

[TheMonzta]

I've been using Valvoline VR1 20w/50 mineral oil in my 24v Opel Monza for a few years and I'm thoroughly impressed with it. It's been used for track days, hard road driving and general commuting. Would it be OK to use 20w/50 mineral oil for my M20 engined 320i as well? Valvoline VR1 is a bit pricey so a slightly cheaper one would be preferable.

[oilman]

I would avoid 20w if you can, the engines dont need a cold crank viscosity that high, 10w or 15w would be better. SAE50 is fine.

Plenty of fully and semi synthetics to choose from here http://www.opieoils.co.uk

Cheers

Guy.

[topspark]

Guy ,

Our mechanical type people at work are starting to use some oil for gearboxes called "royal purple" .

They have had some very good results using this stuff and wondered what your thoughts were on it and have you used it / had experiences with it.??

We are using SYNFILM GT 68 for our gearboxes , would this be of use in the E30 anywhere ??
Our gearboxes are large "santisalo" for paper machine drives and vacuum pumps.

cheers

lee

PS . link to website... http://www.royal-purple.net/

[oilman]

We had some of it tested last year, not sure what one you are using.

My worry would be the fact that it doesn't carry any BMW Approvals at all. I would stick to the BMW Approved ones like Castrol and Fuchs as these were developed with BMW and are probably best.

Cheers

[Black_Potato]

Any views on Rockoil as a brand ? feel free to PM me if its not something you want to post.

[Black_Potato]

I've been using Valvoline VR1 20w/50 mineral oil in my 24v Opel Monza for a few years and I'm thoroughly impressed with it. It's been used for track days, hard road driving and general commuting. Would it be OK to use 20w/50 mineral oil for my M20 engined 320i as well? Valvoline VR1 is a bit pricey so a slightly cheaper one would be preferable.

Last year this was the oil of choice (VR1 20w50)for the PBMW guys runing 320i's and 318i's and they have been very happy with it. The refresh schedule would have been very high for a road car though, i.e. they would have swapped it every few races, some every race.

Due to a change in suppliers/availability there is a chance we will run a Semi Synth by Rock oil, maybe 15w50.

Some on the grid do run oil from Opieoil & I have run Silkolene Pro in my lotus for some years, if it wasnt for the price I'd happily run it in the BMW as well.

[oilman]

Any views on Rockoil as a brand ? feel free to PM me if its not something you want to post.

As a brand they are ok, they make some good performance oils and are popular with bikers, dont no too mcuh about their 4 wheel range. They also do plenty run of the mill stuff too.

Any particular one your looking at?

Cheers

Guy.

[Black_Potato]

We are looking to replace the VR1 race oil we ran last year which we could get at trade price for the series, we have a similar offer for rockoil and have been offered the semi and fully synth ranges to pick from.

The ones I expect would be of interest are....
Guardian Semi
15w50 or 20w50
Synthesis Fully
10w60 or TRM20w60

The Semi is very cheep and can afford to be changed after every race meet without any real concern over the cost, the fully is 2-3 times the price so for some could become an expensive habit over the year.

Cars are generally running high milage 320i (6 cylinder known for oil starvation) and 318i 4 cylinder engines.
The series stipulates stock engines so power is something like 130bhp. some people run oil coolers others dont.

[maxlee]

verry intresting read i just bought some holfords 15/40w oil for my 318i will that be ok or should i take it back and get some thing eles

[oilman]

We are looking to replace the VR1 race oil we ran last year which we could get at trade price for the series, we have a similar offer for rockoil and have been offered the semi and fully synth ranges to pick from.

The ones I expect would be of interest are....
Guardian Semi
15w50 or 20w50
Synthesis Fully
10w60 or TRM20w60

The Semi is very cheep and can afford to be changed after every race meet without any real concern over the cost, the fully is 2-3 times the price so for some could become an expensive habit over the year.

Cars are generally running high milage 320i (6 cylinder known for oil starvation) and 318i 4 cylinder engines.
The series stipulates stock engines so power is something like 130bhp. some people run oil coolers others dont.

I would not run any of these and especially a 60! These engine run far better on a proper race 5w-40 synthetic, it also does not zap the power like a 50 or 60.

Try one of these before you try anything else!

http://www.opieoils.co.uk/p-1146-silkol ... gines.aspx

http://www.opieoils.co.uk/p-868-motul-3 ... -cars.aspx

Cheers

[oilman]

verry intresting read i just bought some holfords 15/40w oil for my 318i will that be ok or should i take it back and get some thing eles

A 5w-40 would have been a better choice or even a 10w-40

Check your handbook

Cheers