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MG MGF Technical - Whats the best oil for MPI?

What's the best oil to use for the MPI. I've been using 10W40 Castrol Magnatex. I have also heard that fully synthetic oil can be used too?
Jorg Mendgen

Mobil 1 5/50 IMO.
David

Mobil 1, but only after you have completed 12k miles.


Ralph
Ralph

Hi,

I don't think there is an absolute best oil for the MGF, or for any car. I would use the top of the range automotive oil from one of the reputable manufacturers, designed, as the marketing says, for modern engines. That would be API SJ (soon to be SL), ACEA A3, B3 or better. That will mean one of the synthetics or synthetic blends, which includes Magnatex. The top quality (i.e. expensive) semi and full synthetics are all excellent oils, just chose your manufacturer. If you support Shuey, go for Shell Helix Ultra. If you're a Coulthard fan go for Mobil 1. If you can't stand the sight of either there's Castrol, I guess.

I would use a 40 weight or possibly 30 weight oil. I would not use the heavier 50 weight oils in a modern engine, there's too much drag and I don't like the chemistry required to get the wider viscosity range.

Regards, Kes.
Kes

Sorry, I forgot to say use the Mobil 1 0/40 not the 5/50 that David suggested.

I've used Mobil 1 in my F for 120k miles and the oil temperature, in my experience, is much lower than with the 10/40 recommended by Rover. With Mobil 1 the oil temperature never went above 120 degrees C, even when using the car to it'e limits. Since I've changed back to 10/40 (mainly because I forgot to tell B&G to use Mobil 1 at the last service, but at 136k mile it had started to use a fair bit of oil, so probably wasn't a bad idea any way) the temperature regularly goes above 120.

Ralph
(A Coulthard supporter)
Ralph

Hi,

More on this. On Friday, on a trip to Halfords (Autoglym Glass Polish, since you ask) I had a look at the oils, as is my habit. Castrol Magnatec (for modern engines) is now 5W-30. There was also a Castrol oil specifically for VW's also at 5W-30, called SL (I think). There seems to be an increasing trend towards 30 weight oils. This weight oil is fairly common in the USA, with moves there now to 5W/0W-20 oils on Ford and Honda, as energy conserving (a saving of 0.1 mpg, and a US gallon at that). The UK Ford Zetec engine (there may be others) uses a 30 weight oil, and if the Fiesta owner insists on Mobil 1 then it is available from dealers, but not off the shelf: presumably Zetec's never need topping up.

Dieter seems to have had some success running on a 0W-30 oil, showing cooler oil temperatures. It seems that the thinner oil circulates faster and transfers more heat to the sump. Is anyone else running on a 30 weight oil (all you unknowing Magnatec users?). I wouldn't have any problems using such an oil. All oils are like Katzenpissen when hot anyway.

Interestingly (this is interesting?) Magnatec is rated API SL. Mobil 1 is rated SJ, as are all the other oils right down to Halford's own cheapest offering. So a petroleum oil has a higher API rating than one of the best synthetics? Possibly the SL rating can only be achieved with a 30 weight oil (thus excluding Mobil 1). So the cheapest oil has the same API rating as one of the best synthetics? Possibly the API ratings are so easy to pass that they are of little value. Maybe the European ACEA ratings are a better indication of quality. Even more interestingly Mobil's website says that 'Single weight oils and oils with a viscosity rating of 10W-40 and higher are no longer API certified because thay are too heavy to meet current fuel economy tests.' It's time for Mobil to make a move, I think. No, I don't know what happened to SK.

An annoying thing is that Magnatec (a high quality oil) is sold in two versions, 0W-30 for 'modern engines' and 15W-40 for 'basic engines'. Both come in the same identically coloured can, with just a small panel on the front to distinguish between them. Just be careful to get the correct one - it's the one that costs most.

(I might not have all the numbers spot on as I'm working from memory, so excuse small errors!).

Regards, Kes. (Ferrari fan, but on Mobil 1)
Kes

Surely the viscosity range is marketed to suit the climate of the country of sale? That's why Mobil market '1' as 0/40 in the UK , against 5/50 in France (larger country, one blend covering climate differences from Med to Normandy) . Personally what's good enough for the French climate is good enough for me, the UK being less variable. The little matter of 4 litres being 32 quid in UK against 18 in France is what sways me.
David

I thought the VVC mechanism used oil temperature as the switch for activating the VVC mechanism after the car had warmed up? Surely changing away from the standard recommended oil could upset this?

Leigh
Leigh

Just read the thread heading, sorry. Didn't realise this was just for the MPi.

Leigh
Leigh

Hi,

<the viscosity range is marketed to suit the climate of the country of sale?> To a certain degree, yes, and particularly in areas of extreme cold. However the move from a 40-weight to a 30-weight oil in temperate climates is being driven by developments in engine design and manufacture, and those are at least partly in response to more stringent emission directives from the government and the EU (and pressure from the public?). I can see this trend continuing: in a few years cars will be running on 20 and 30-weight oils, with more sophisticated filtering giving change periods extending to the life of the car. Personally I wouldn't use a 50-weight oil in either of my K-series cars. An MGB, yes: a K-series, no. A 40-weight oil is thinner at startup temperatures, say 5 to 15 deg C, and that's where a thinner oil is required. Also the engine has been designed to run and does run more efficiently on a 40-weight oil. The 50-weight oil isn't going to kill it, it just isn't my choice.

Does Mobil not sell 0W-40 in France? I can't see why not. I don't agree with the climate explanation: the variance isn't that wide and I believe that 0W-40 is sold in Spain and Cyprus (Spyros, Bruno?) and it's far hotter there. I suppose one could ask Mobil, but they've never answered my emails before so I don't think I'll bother now. As for the cost of the stuff, Mobil 1 is sold in the US at around $4 a US quart (roughly a litre), about a tenner for a four-litre can. That does make me peeved!

Yes, the additional oil temp sensor on the VVC cylinder head (well, the ECU really) determines the viscosity of the oil from its temperature. I'm not sure how accurate this is, it must be a bit of an estimate as the difference between the min and max viscosity within the SAE 40 rating is about 30%.

I'm sure there's a great deal more that could be said about lubrication and viscosity, it's a highly complex subject at which I can only scratch the surface.

Regards, Kes.
Kes

useful points Kes; I was in dialogue with Mobil a couple of years ago over the differences between UK and French market products and they suggested the climate as a reason. However when I moved on to the subject of price they went very tight-lipped on me ! Don't know if they are doing more than 1 grade inFrance now, Carrefour certainly only stocked the one up til last csummer, I'll check next week. In what way is the Kseries designed for 40W oil? Is it just the oil pump and passages or bearing tolerances or what ?
David

Hi,

I think I was a little vague there, David. There's nothing specific that applies to the K-series engine, it falls into the generation of modern high-revving tight-tolerance low-emission engines which use a lighter oil. Well, modernish, as it is some 15 years old now - but still good. Using a more viscous oil won't necessarily hurt it, but will generate more drag, heat and emissions. The extra drag and emissions probably won't be noticeable, the heat may be, as Ralph and Dieter have shown from experience. Still, I'm no great authority, just a lone opinion!

Regards, Kes.
Kes

Kes

The only Mobil 1 Grade available in Cyprus currently is 15W-50. I have no idea why though.

Cheers
Spyros
Spyros Papageorghiou

And in france , only the mobil 1 10/40 is available...
Benjamin

Hi

Can I widen the climate thing beyond France as like Spyros am somewhere hot! Summer temps will 30-35C and all I can get is 15W/50.

In this environment is this OK or should I ship in some 30?

Thanks for any advice

Bizoh
JY6842 (formerly S345 MLU if Mike is reading)
Bizoh

Hi,

Bizoh, my opinion (and that's all it is) is that Mobil 1 15W-50 will be fine in your car (assuming that you are using Mobil 1). My reluctance to use a 50-weight oil is mainly because Western Europe has a fairly temperate climate, and is based more on 50-weight petroleum oils. In any event we know that David is using Mobil 1 15W-50 in the UK quite happily.

Mobil's website says that M1 15W-50 is '..especially suitable for high-performance cars, particularly hot running or heavily loaded vehicles and special high-tech imports', where 0W-40 is '..formulated for newer European cars, especially those with advanced-technology, multi-valve engines.' I wonder where the MGF fits into that lot?

I also assume that your oil temperature is not excessively low or high? If it's OK then be happy with the 15W-50.

Regards, Kes.
Kes

According to the chart in the MGF manual a 15w-50 oil should be used when the ambient temperature is between 0 and 45+ degrees celcius. So it should be OK for both Hong Kong and Cyprus.

On the other hand a 10w-30 oil is recommended for a temperature range of -20 to 20 degrees.

Spyros
Spyros Papageorghiou

Back from Le Mans and a little French Mobil 1 research. The grade I've been buying over there and using in several motors for around 4 years now is actually 5/50. It's still on Carrefour's shelves in the 3 branches I happened upon, at around £18.50 for 4 litres. In the Rouen branch I also found some 0/40 and guess what, the shelf display is labelled up with lots of 'Nouvelles'. It's gone up (of course) and was priced at 22.50 for 4 litres, still 30% less than UK prices. Whether the new grade will replace the old or complement it, I have no idea. Be careful if looking for this stuff as Mobil do at least 3 other grades, but none of them are fully synthetic '1' although at a glance the packaging is all too similar.
David

Just changed to magnetec 5W-30.My first impressions were that the oil temp definetly took longer to reach its normal 120 degrees. In case anybody wondered !
S Laithwaite

The new Magnatec 4 litre bottle is a triumph of form over function. I've ended up decanting the oil into an old Mobil 1 oil bottle in order to top up the F. Using the Magnatec bottle most of the oil ended up on my driveway.

Ralph
Ralph

Mobil 1 is marketed as 5/30, and 10/30 in the US. The 10/30 is clearly recommended on the $4.89 quart, as for "higher mileage engines".

I use the US spec 5/30 mobil 1 in my MGF, and I can't comment on oil temperature, I've one of the faulty, high reading oil temp meters.
George

So have we come to a conclusion?
The best oil is......?
Kingsley

Kingsley, from what I can see it seems that the conclusion is, for an engine with 12k to 140k miles, Mobil 1 is best. What grade you can get depends on where you are, what the local weather is, whether there is an R in the month and the phase of the moon!

For engines with mileage outside this range the standard 10w40 recommended by Rover is best. There seems to be no agreement on the make though.

Ralph
Ralph

pretty fair synopsis Ralph ! There is a degree of 'you get what you pay for' so a fully synthetic is better than a part-synthetic, which in turn is better than mineral oil.
David

I agree with spyros. choose oil viscosity based on ambient temperature. i.e during summer go for 10w50 or 15w50. during winter 5w30, or 10w40.

regards
Jason

This thread was discussed between 24/05/2002 and 25/06/2002

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