28 replies to this topic

[MiniBonkerz]

Right i have read a few posts about this still confused i have a 98 mpi what oil do i use 20/50 i guess but do i buy fully synthetic, mineral or a blend?

[datsun100a]

20/50 mineral, it's an a-series engine at heart.

[THE STIG]

late minis spi/mpi use 10/40 not 20/50 like earlier engines

dont use synthetic get a good name brand or if using cheaper stuff do more freqent oil filter changes

[MiniBonkerz]

10/40 isnt that for modern engines like said it is an a series at heart

[THE STIG]

10/40 isnt that for modern engines like said it is an a series at heart

mpi is a modern engine fuel injected ,cataliic converter etc

10/40 is want its designed to run and thats what the manul states

Edited by THE STIG, 12 July 2009 - 09:04 AM.

[MiniBonkerz]

i know it'smodern in that respect but the block is still an a series old lump if it's what the book states i will follow it

how's the hospital food or are you home yet?

[THE STIG]

still in hospitl will be for a while

search in this section turned up replies in earlier topics but cant paste was in the last month

is to due to older classic oils using aditives that can bugger up oxegen sensor and cat

[nicksuth]

I run my 98 MPi on 10W/40 and it runs fine, as The Stig says, you can knacker your Lambda Sensor using 10W/50.

PS - any nice looking nurses on your ward )

[L400RAS]

is to due to older classic oils using aditives that can bugger up oxegen sensor and cat

Hi Stig,
Sorry, could you explain this statement? Whats in 20W50 thats not in 10W40 that would hurt the cat/ lambda? They are both "classic" oils due to being mineral, not semi etc; the reason i ask is i have just changed my oil to 20W50, after being on 10W40 for 3 years, on the recommendation that it would be better for the gearbox, as that hasn't changed when they introduced the Mpi (apart from the diffs). The only way oil could come in contact with the cat and lambda would be if the engine is burning excessive amounts? - thus, any type of oil could do the suggested damage? Please let me know your reasoning,

many thanks
Ryan

Edited by L400RAS, 13 July 2009 - 06:35 AM.

[Juju]

I've used 20/50 & 10/40 mineral AND synthetic in my mpi over the past 3 years - I do 10,000 miles a year - the only difference I've noticed is the gloopier oil makes the gearbox more treacley. Which I like. That's it.

It doesn't actually matter what you use. It ain't gonna make the thing explode. But other people can be veeeeeery particular about what they want to put in their cars....

[Joloke08]

I would still tell anybody to use a good quality 20w50 mineral oil over anything else. As said it makes me laff when peeps say ive got an injection but at heart its the same A series that appeared in the Morris Minor 60 years ago

As your Oil goes inside the engine and lubricates the gubbins and then sits in your gearbox all night and that the internal gubbins are roughly the same as theyve allways been id go by what was used and recomended for the first 30 years of the Mini not the last 10

As Juju said your engine or gearbox isnt gunna go bang if you use 10w40 but what you will get is more leaks and i found the newer sooper dooper oil went dirtier quicker too

Boris as you probably all know is an Automatic and he was slipping out of gear etc with 10w40 (the supplying garage did that oil change not me) and now with good old Duckham Q 20w50 mineral he,s quieter,and smoother and changes up and down better

He still slips out of gear occasionally but nowhere near as much as he did
Deep down i believe the 10w40 which incidentally was synthetic (the garage thought they were doing us a favour ) actually caused premature wear to his Gearbox

So id never put 10w40 in again and Boris is getting an exchange/rebuilt gearbox soon and nasty synthetic 10w40 will never pass its cogs!!

Just My Opinion based on experiences

Huggz
Jodie

Edited by Joloke08, 13 July 2009 - 08:24 AM.

[THE STIG]

is to due to older classic oils using aditives that can bugger up oxegen sensor and cat

Hi Stig,
Sorry, could you explain this statement? Whats in 20W50 thats not in 10W40 that would hurt the cat/ lambda? They are both "classic" oils due to being mineral, not semi etc; the reason i ask is i have just changed my oil to 20W50, after being on 10W40 for 3 years, on the recommendation that it would be better for the gearbox, as that hasn't changed when they introduced the Mpi (apart from the diffs). The only way oil could come in contact with the cat and lambda would be if the engine is burning excessive amounts? - thus, any type of oil could do the suggested damage? Please let me know your reasoning,

many thanks
Ryan

as i said in the post ,classic oils, they tend to have addetives for higher milage engines which can be bad for lamda and cat

did not say all 20/50 oils you will have to read other post to see what others said

gearbox has nothing to do with it will run just as well on 10/40 all the numbers are is the heat range for the oil

all engines burn oil in nornal running may only be a tiny amount of vapour but it all goes down the exhhaust

the manual states 10/40 thats what they recommend

if you wnat to run something differant thats upto you does not chnge the fact they state 10/40

[bluedragon]

Some of the confusion may be that there is still a contingent that insists synthetic oils are unsuitable, and then there are people like me who have used synthetic on A-Series motors for years, in daily driving, with no problems.

I posted elsewhere I just completed a 5,000 mile trip including at least 7-10 hours of constant operation at full throttle, and it used only 2 quarts. If I hadn't been running flat out, it probably would have used no more than 1 quart. Top-ups coincided with long periods of max throttle. I use 20/50.

Even the "classic" oil you can buy today has little similarity to motor oil produced in 1960. Oil techology has advanced enormously in the past 50 years. Even if I could get 10 gallons of the stuff out of a time machine I wouldn't use it.

The main differences between "classic" oils (made today) and oils for modern cars is in the additive package. Due to emissions, some of the additives used for older technology cars have been reduced. As mentioned, these additives can pollute the emissions control equipment. But O2 sensors and cat converters have been around for decades. Mini emissions tech dates from the 90's, so obviously oils meeting those standards are fine.

You can still get oils of all types (conventional and synthetic) with suitable additive formulations. The basestock (synthetic vs. conventional) has nothing to do with it.

Synthetic basestock have oil molecules that resist shearing and breakdown far better than conventional oil. Just what is needed in a engine-oil lubricated gearbox. My engine has at least 60,000 miles on it, and it doesn't leak any oil either, believe it or not! I fixed the rocker cover seal and one diff/driveshaft seal over 3 years, and it ceased leaking oil. Oil leaks are caused by leaky seals, not synthetic oils as many people claim.

The only claim I don't really follow (regarding synthetic) is I don't leave the oil in for 15,000 miles. I change it every 6,000. If I were using conventional oil, a 3,000 mile change is a must. I believe the synthetic after 6,000 miles is as least equal in stability to fresh conventional oil, but I want to flush out the metal shavings and swarf from the transmission. I don't know if there is any scientific backing behind this, but it makes me feel better.

Edited by bluedragon, 14 July 2009 - 12:01 AM.

[jamesmpi]

personally i would recommend using Millers Motorsport CVT Semi Synthetic 20w50 Oil. It has a very good additive which helps to preserve your gearbox (which is ideal seeing as it sits in it all day long). This was recommend to me by the guys who build my 1380 as they race miglias and use it in their race/road engines....bit pricey though at £40 for 5 litres, but then again oil is cheaper than metal!!

[greg.harvey]

the manual states 10/40 thats what they recommend

if you wnat to run something differant thats upto you does not chnge the fact they state 10/40

Not my manual. I have a 1999 MPi with original books and it states 10W/30. Can scan the page if you like.