18 replies to this topic

[oliver122]

ive brought 20 litres of oil of a lad i work with as he used to work for an oil firm , he told them what my mini was and they gave him the recomenned oil ,and its 10/40 , will it have any adverse affects to my mini , its coming up to the 100k mark on the milage,my mini does have an oil leak , will it be worse

[maggies_minder]

it maybe as 10/40 is thinner than the recommended 20/50.

asking topics on oil always cause issues on this place. minis have been around for so long everyone has an opinion on what oil is best.

it might be worth searching and drawing your own conclusions.

[greensilver mini]

i think 10/40 is more better for slighty worn engines thats what iv been told anyways

[mike.]

I'd stick with 20/50.

[maggies_minder]

I'd stick with 20/50.

+1 most agree that thicker oil is better due it being shared by the gearbox and engine.

[bcjames]

I use 10w40 in my mini.

[Ocado Man]

Isn't the grade of oil used sometimes determined by the climate that you live in?

[Guess-Works.com]

It will have no adverse effects on your engine or transmission, and in fact, contrary to popular belief, is the recommended oil for the mini in our temperate climate according to the manual, but likewise, 20/50 will not adversely affect your engine either.

What you must do, with whatever oil you decide to use, is change it regularly.

[Mini_Magic]

i think 10/40 is more better for slighty worn engines thats what iv been told anyways

I'd actually say 20W/50 is better for a worn A-Series, as it's ticker.

I've had both 10W/40 and 20W/50 in my last Mini and the 20W/50 was far better, it ran better and the gear change was smoother.

[twrminisport]

i think 10/40 is more better for slighty worn engines thats what iv been told anyways

I'd actually say 20W/50 is better for a worn A-Series, as it's ticker.

I've had both 10W/40 and 20W/50 in my last Mini and the 20W/50 was far better, it ran better and the gear change was smoother.

I had the opposite. I run 10w40 because its much smoother over 20w50

[yellowmonster]

Mmm...it's all down to personal experience and likings I guess.
I know that Minis ran off the productionline with 10W40 in their bellies, so that's what the manual says.
Believe me, I've tried a fair share of different oils over the years, and my personnal opinion is:

20W50 keeps the oilpressure slightly higher, makes the engine somewhat quieter and makes shifting gears easier.
It also reduces oilburn and leaks.

That said, there's no problem using the recommended 10W40 in an old Mini, but keep an eye on your oilpressuregauge..

Edited by yellowmonster, 17 August 2011 - 06:13 PM.

[lolipop]

If you've got 20 litres you might as well give it a try, at least you'll have plenty to top up with!

[Cooperman]

With a high-mileage Mini use only a good quality 20w50 mineral oil (Castrol Classic, Halfords 20w50, Millers, Penrite, Valvoline or similar. Your thinner 10w40 is also probably a synthetic or semi-synthetic and that's not as good as a mineral oil.
It's the gearbox which suffers with thin or synthetic oils as it shares the engine oil. Ideally the gearbox would have an EP80 gear oil, so even 20w50 is a bit thin for the 'box.

[R1minimagic]

Your thinner 10w40 is also probably a synthetic or semi-synthetic and that's not as good as a mineral oil.

This is quite a simplistic view as synthetics are superior to mineral oils in most respects.

What you mean to say is use a higher viscosity oil, which tend to be mineral oils!

[Cooperman]

Your thinner 10w40 is also probably a synthetic or semi-synthetic and that's not as good as a mineral oil.

This is quite a simplistic view as synthetics are superior to mineral oils in most respects.

What you mean to say is use a higher viscosity oil, which tend to be mineral oils!

Synthetics are superior to mineral oils in applications designed for synthetics and I would never use anything else in my BMW 325i. Minis were never designed for synthetics though. I once tried a top quality synthetic which an oil company gave me for rallying. I used it on one event, then had to spend almost £1000 rebuilding the gearbox and engine as, at up to 7400 rpm, the main bearings, syncros and cam bearings all went 'up the pictures', so I do think I speak from expensive experience.
I discussed this with a really experienced senior engine design specialist who worked for Cosworth at the time and with whom I did a lot of business. His comment was "If you run an old A-Series engine & box on 'weasel p**s', what do you expect". He explained the need for a thicker minerqal oil and recommended an oil called Kendall 20w50 which was made from Pennsylvania crude oil. That is NLA in the UK, so I always use valvoline 20w50 in the rally Minis and Castrol Classic 20w50 in the Mini road cars.
Sorry if it seems simplistic, but it's a simple answer which is needed here really.