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MG MGF Technical - Which OIL to use?

Hi,

Which oil do you recommend for the VVC?

Thanks

Rhys
Rhys

BP?
Don

OK, another girlie question from me (but the husband doesn't
know either)....

What are those strange numbers on the side of oil cans?
I always look for 10W-40 (well I think that's it I always
have to double check, I try to avoid WD40!), but sometimes
it is difficult to find - so what do the numbers really mean?

Hazel
Hazel

Hazel,

The oil in your engine needs to be nice and runny when the engine is cold both to give decent lubrication and not to put stain on the beast. You also want it to maintian vesocity when the engine is bombing down the autobahn on a hot summer's day.

Problem is oil gets runner as it warms. The oil companies therefore have the problem of ensuring the does the business when cold and hot. The two numbers therefore represent the viscocity when cold and when hot. I beleive the W stands for winter so the first number is the vescosity on a cold winter morning, and the second when the engine is at full operating temperature.

This is what I was told anyway.

Cheers and hello

Patrick

PS Had to laugh about your comment on the other board that you don't push your car. Just remember some us us were trying to keep up with you a couple of weeks ago!
Patrick

The type of oil you use depends on the age and mileage of the car.
If the engines is brand new a cheap oil is good enough to let the engine
run in. A semi synthetic oil should then be used at its first servive or
12000 miles. A pure synthetic oil should then be used at the second service or
24000 miles (or early).

If you use a pure synthetic oil to soon the engine will never run in as it is so
slippery and good it prevents engine wear.

Oils to use (depending on mileage) pure synthetic oils:-
Mobile 1 or similar Esso superlube (I think)

Tom
P305 DPB
Tom

Tom,

As of new I've been using 'SHELL-HELIX',
which is synthetic as far as I know.
Just since the car reached 18.000kM it
behaves like 'run-in'. Uses not a drop of oil
between services (8000kM apart). I drive it
mostly to work up & down 30kM mainly highway.
Once a year I take it on a long trip to the Alps.
Then I drive between 150-170 kmh on the Autobahn
(top down). In winter oct-may it is garaged.
In spring it is like getting a new car again!
In Holland I mostly keep below 150kmh, but I always
let it heat up first (about 10kM). I think the
car is brilliant. I started to get sleepless
nights from all the negative stuff on this site
but now I realise that it probably is related
to the driving style (HGF I mean).

I don't see the need to use fossil oil to run
the car in. The difference in friction is only
3-5% (roughly what you use less in fuel).
It might take a bit longer to run it in, thats
all!
Daniel

Daniel,

I realise that it probably is related to the driving style (HGF I mean).

Now don't you start :-)
Tony

>>Problem is oil gets runner as it warms. The oil companies therefore have the problem of ensuring the does the business when cold and hot. The two numbers therefore represent the viscocity when cold and when hot. I beleive the W stands for winter so the first number is the vescosity on a cold winter morning, and the second when the engine is at full operating temperature.<<

Yes, that's pretty much it. The lower the first number the better the oil's resistance to thickening as it gets colder. The higher the second number the better the oil's resistance to thinning as it gets hotter. So e.g. in a cold climate Mobil 1 0w40 would be a good choice. In a hot harsh (e.g. competition) environment 15w50 would be a good choice. The latter is what I use in my competition K-series engine. If I were to drive it around in the winter then I'd revert to 0w40.

Mike
Mike Bees

Hi Patrick (& Ann!). Thanks for the explanation (and also
to Mike Bees).

>PS Had to laugh about your comment on the other board that
you don't push your car. Just remember some us us were
trying to keep up with you a couple of weeks ago!

I was just trying to keep up with Ted!

Anyway I don't think I said I never push the car. I just
don't think it is a good idea to push it when cold. Even
when I do push it I keep an eye on all the dials. I think I
have hit the rev limiter twice in just over 2 years - I
don't think that is TOO bad ;o)

P.S. I have some pictures from the Rally that should
hopefully get on my web site later tonight.
Hazel FAO Patrick

Hi,

There's enough stuff about oil on the internet to keep you confused for years. Shell Helix Ultra is the full synthetic (5W-40), and Helix Plus semi-synthetic (10W-40). Despite what the stickers say on Mika's car, the only oil recommended for the MacLaren road car is Shell Helix Ultra. Now that's confusing. Ferrari also insist on Helix Ultra if you want to keep the warranty: both these manufacturers, and Porsche too I believe (as well as some others), use synthetic oil from new.

A Shell spokesman said that 'Synthetic oils.. derive from crude oil, but by carefully selecting the feedstock and using a hydrogen-based synthesis process, we can physically restructure the hydrocarbon molecules to create a more consistent and homogenous end product. This process gives synthetic oils performance characteristics which are very much better than.. mineral oil products'. And I thought synthetic oils came out of the laboratory.

The lower number in the classification defines the oil's viscosity at low temperature and the 'W' denotes its suitability for winter use. The higher number denotes its viscosity at 100 deg C. The high temperature viscosity measurement is always taken at 100 deg C but the temperature for the lower measurements vary: 5W is measured at -25 deg C, 10W at -20 deg C, and 15W at -15 deg C. Now that really is confusing.

Oils on the continent also may have a different viscosity rating from the same product in the UK. I wouldn't mind an explanation of this from the manufacturers.

The upshot of all this is that any recommended oil of the correct viscosity will be fine for the engine: I shall switch to synthetic at 12000 miles for many reasons, but mostly the better cold start circulation and the far slower degredation between changes. I believe the adverts. I would not dream of putting any additive in the oil.

The only moan I have about synthetics is the thoroughly mean way the major producers sell it in 4 lt packs, not quite enough for any oil change. Do they think we won't notice the price when we buy the additional litre? Mainly for this reason I run my 214 on Halfords full synthetic (a full 5 lt there), but I suppose it will have to be Mobil 1 or Shell Ultra for the F. The strange thing is that after 6000 miles in the 214 there is a slight seep from the sump gasket. Coincidence, or do synthetics still cause gasket leaks, or what?

Final comment: Castrol's synthetic RS is 10W/60, miles away from the other offerings and (I would have thought) unsuitable for the F, and my 214 for that matter. Why this viscosity rating?

Regards, Kes.
Kes

The following extract from the workshop manula relates to the small print that is found on the side of the oil cans we buy...

"Use oil meeting specification RES.22.OL.G4 or the
requirements of CCMC G4, and having a viscosity
band recommended for the temperature range of
your locality. Where oils to these Rover and
European specifications are not available, well
known brands of oils meeting API SG, SH or SG/CD
quality should be used."

Rog
.
Roger Parker Tamworth roger.parker@virgin.net

Plenty on the net to elucidate and educate....try:-
http://members.aera.org/enginetech/takea.htm
http://www.audicoupe.demon.co.uk/engineoil_bible.html
http://www.geocities.com/MotorCity/2195/engineoil_bible.html
http://www.repairfaq.org/filipg/AUTO/F_oil_facts.html
http://www.mobil.fi/oneracing/about/products/engineoil/index.html
HTH
david.smith@stones.com

Some syenthetic oils are very thin, Mobil 1 for example, and I've had experience of very slight oil leaks with this but not with thicker oils.

Syenthetic oils main advantage is that it will not breakdown at normal engine opperating temperatures whereas non synthetic oil will. The most graphic example of this is in high milage engines which use small holes drilled in a pipe in the camshaft to lubricate the cam bearing. The black soot deposits formed as the mineral oil breaks down causes blockages in the pipe and cam beearing failiure.

This soot deposit will furr up all oil ways with time so syenthectic oil is best.

I personaly perfer castrol magnetec as it is a bit thicker than most syenthetic oils. Syenthectic olis also have a wider operating temperature band, they do not get as thick when cold or as thin when hot as mineral oils.

I recommend using a ggod quality flushing oil at every oil change as well.

Andrew.
Andrew

Hi,

I don't own any VVC but I have the oil changed last week on my 1.8i and it was with Castrol GTX something according to the mechanics (9 cans of 0,5L !)
I think it's the one which is recommended by Rover isn't it ?
(does it mean it is the best suitable ...)
I think viscosity is 10W40 for the 1.8i like for the VVC whereas the VVC is more in the revs.

Nice rain today in Paris :-(
Normal, it's the week-end.

Cheers
Jérôme
Jérôme - Paris

Hi all,
Regarding Kes comment on some manufact. using syntetic oil straight on from customer delivery is probably that these "exotic" cars have their engines run in at factory in a bench. At least Porsche run in all their engines + a good bash at their test circuit before leaving factory. Had a chance to see it myself some years ago when visiting the factory. The more "common" cars get their first run in when they are loaded /reloaded from factory transport !!! Have had a chance to see that too when Japanese cars were unloaded at nearby harbour. And we try to keep engine below 3000 revs. etc. for first 1000 miles. Ha Ha !!

Regards , Carl.
Carl

Hi,

Andrew seems to imply that Castro Magnatec is synthetic, it isn't, not a full synthetic anyway (I don't have details to hand), and Jerome's car was filled with Castol GTX. Castrol seem determined to confuse me, they market (in the UK)

GTX for basic engines, conventional protection
GTX Magnatec for basic engines, enhanced protection
GTX for advanced engines, conventional protection
GTX Magnatec for advanced engines, enhanced protection

all in fairly similar packaging, so watch what you buy or are given!

Trawling through some of the oil info in the web it appears that 10W-40 oil is an absolute no-no in the States, and some manufacturers may refuse warranty claims if it's used. It's all to do with the VI improvers required to produce this viscosity range. This might apply only to dino oils (lovely phrase), I don't think that synthetics need so much adulteration. So why do we have to use 10W-40 in the UK?

Regards, Kes.
Kes

This thread was discussed between 07/10/1999 and 10/10/1999

MG MGF Technical index

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