20 replies to this topic

[fraggle_cooper]

Model:cooper mpi
Year:1998
:



a guy on here kindly recommended me this oil:
http://www.halfords....tegoryId_165581
as i am servicing my mpi soon and as i know nothing about oil, and don't want to be the reason my mini dies i want to make sure that it would be a wise choice.
he said it seemed to work well with the engine but the halfords oil guide says to use 10w40...whatever the hell that means

[WiredbyWilson]

the halfords guide is bull.

stick with the above rocmmendation and you won't go wrong.

[Pauly]

http://www.theminifo...howtopic=164902

Best to use 20w50 because of how the minis engine shares its sump with the gearbox.

Have heard of people running 10w40 aswell with no problem, I run 20w50 just to be safe.

Rover simplified its oil grades over the years, whilst most Rover models where getting 10w40, the mini was still getting 20w50 or 15w30, so it was changed to 10w40 so the costs where kept down.

Edit: Typo.

Edited by Pauly, 29 July 2010 - 09:10 PM.

[WiredbyWilson]

I have never seen 20w40 on sale though

[fraggle_cooper]

i just noticed it even has a mini on the tin
i can believe it isn't upto much, nobody in that place seems to know a right lot about anything to do with cars!

[Stevee]

you can run

20w/40 & 10w/40 in a Mini

auto data says both of them

my 79 is running 10w/40 and runs fine

[Pauly]

I have never seen 20w40 on sale though

Edited, only put it once .

[fraggle_cooper]

http://www.theminifo...howtopic=164902

Best to use 20w50 because of how the minis engine shares its sump with the gearbox.

Have heard of people running 10w40 aswell with no problem, I run 20w50 just to be safe.

Rover simplified its oil grades over the years, whilst most Rover models where getting 10w40, the mini was still getting 20w50 or 15w30, so it was changed to 10w40 so the costs where kept down.

Edit: Typo.

very handy thread that pauly, i wish i could figure out how the hell that search button works,
thank you very much for the help guys!

[fraggle_cooper]

can anybody clear up what the numbers mean?
is it something to do with the thickness and then the viscosity of the oil?

[Stevee]

Comma Oils

do 20w/50 if you want it you can get it from any Wilco Car Stores :]

[huw_jenks]

Haynes manual recommends 10W40, but I'm guessing they were given the info by the Rover dealers of the time.

[Cooperman]

The A-series engine would be happy with 10w40, but really the gearbox needs an EP80 or EP90 gear oil. As the engine and box share the same oil, the only sensible compromise is 20w50 mineral oil, unless you want to risk the synro hubs in the gearbox.
The recommendation from Rover to use 10w40, which others have copied is, like much of their engineering, c**p.

[TimmyG]

can anybody clear up what the numbers mean?
is it something to do with the thickness and then the viscosity of the oil?

The numbers refer to the thickness (viscosity)of the oil at certain temperatures.
Before multigrade oils you had single grade. These were went from 0w -25w, which were considered for winter use, as they were thinner and had they're own set of standards , the lower the temperature, the lower the number needed. Then there were the summer grades which were 20 - 60 and had they're own set of criteria to meet. So you would fill with appropriate summer oil and then change to the recommened winter oil in winter as the summer oils would get too thick in cold conditions and winter oils too thin in summer.
Most multi grade oils have additives which get thicker with temperature, so the oil doesn't get so thin at higher temps and you have an oil that meets say a 20w criteria for winter and also the 50 grade criteria for summer. 20w50, an all season oil.
The problem is when the additives breakdown the hot viscosity is lost, ruining the oils ability to lubricate when hot. I.e. it reverts back to being a 20w single grade.
This is the beauty of synthetics, they are more temperature stable in the first place which means you can make them to do the same job with less thickener additives so that they don't degrade so quickly. Or on the other hand make them so they have a very wide temperature range such as a 5w50. This means you get better gear changes, better power and therefore better fuel economy from cold and the hot thickness hasn't changed at all. from a 20w50. Hope this helps.

Edited by TimmyG, 31 July 2010 - 11:14 AM.

[TimmyG]

The A-series engine would be happy with 10w40, but really the gearbox needs an EP80 or EP90 gear oil. As the engine and box share the same oil, the only sensible compromise is 20w50 mineral oil, unless you want to risk the synro hubs in the gearbox.
The recommendation from Rover to use 10w40, which others have copied is, like much of their engineering, c**p.

The 80 and 90 part of an EP 80 or 90 gear oil is incomparable to the numbers used in engine oils as they use different standards apparently. It doesn't mean they are any thicker than 20w50. The EP part of it is the most important.

[Cooperman]

The A-series engine would be happy with 10w40, but really the gearbox needs an EP80 or EP90 gear oil. As the engine and box share the same oil, the only sensible compromise is 20w50 mineral oil, unless you want to risk the synro hubs in the gearbox.
The recommendation from Rover to use 10w40, which others have copied is, like much of their engineering, c**p.

The 80 and 90 part of an EP 80 or 90 gear oil is incomparable to the numbers used in engine oils as they use different standards apparently. It doesn't mean they are any thicker than 20w50. The EP part of it is the most important.

Quite correct. The EP stands for 'Extreme Pressure' which is what is really needed for the old BMC gearboxes as fitted to AH Sprite, A35, A40, Minor, etc. However, the EP80 & EP90 are very much thicker than a 20w50 and with different type of oil as well. The problem is that the Mini gearbox is really an A35/Minir box turned sideways and fitted into the Mini alloy sump and modified for FWD. So really the Mini box needs and EP80/90, which it can't have as it shares its oil with the engine. Modern synthetics are not really suitable for the gearbox as fitted to the Mini and can cause the syncro hubs to fail quite quikly, so a compromise is a good quality 20w50 mineral oil such as Valvoline Raing 20w50, Castrol Classic, etc.