17 replies to this topic

[MiniMonty]

Just been in a debate about oil.
I've always used synthetic 15w/40 (because it makes technical sense in a small bore old engine).
But discovered that there seems to be a "Mini Mantra" to use 20w/40 mineral oil !!

I'm honestly shocked.

Can anyone enlighten me ?

[Retro_10s]

There is a 'mini mantra' to use 20w50 Because it increases Gearbox and differential longevity.

Please do a search, there are literally hundreds of oil threads. All with the same answers. Buy the best oil you can afford, they're not all the same, a lot of time goes into creating the correct blend and an awful lot of research goes into the detergents used etc....

[Guess-Works.com]

more to the point... synthetic is really bad for the mini, unless it's a really high quality one and is changed very regularly.

Use a Mineral oil, either 10/40 or 20/50, I prefer 10/40 as I don't like pumping treacle around my engine, 20/50 is good for old oil burners, which admittedly most minis are.

[ian2000t]

more to the point... synthetic is really bad for the mini, unless it's a really high quality one and is changed very regularly.

Which really negates the idea of using Synthetics.

Use a Mineral oil, either 10/40 or 20/50, I prefer 10/40 as I don't like pumping treacle around my engine, 20/50 is good for old oil burners, which admittedly most minis are.

I always thought the gearbox needed 20w/50? I was always told 10w/40 is too thin for the gearbox causing premature wear.


I use Duckams 20w/50 (which I believe was designed for the Mini) and change it regularly. Never had any problems. Did manage to kill my first engine when I looked in the Rover book and followed their advice of usig 10w/40 though. oil pressure dropped to 18psi at 4500rpm a few weeks after.

[taffy1967]

I did an oil change yesterday and it's still running smooth on Duckhams Q Classic 20W/50.

[spikyrob]

valvoline VR1 or millers trans m for me, after spinning a main and a big end i'd rather be safe than sorry again

[jakson]

hi
im running my mini on 10/40 part synthetic and your scaring me with this talk of it being bad for mini's, how often should i change oil with 10/40 every 3000 miles or so ?

would i be wise to change to 20W/50?

[taffy1967]

Well every 6 months or 6,000 miles is the absolute minimum, but yes every 3,000 miles would be better.

At the moment I'm doing less than 3,000 miles in 6 months, but I'm still changing the oil anyway.

And yes 20W/50 would be best for any Mini. I bought some from here: -

http://www.4wheelpla...p-25000264.html

Delivered free too.

This is similarly good for Minis too: -

http://www.carrotcyc...50/prod_40.html

[taffy1967]

So this should be proof enough?: -

High quality mineral oil formulated for engines from 1960 onwards where engine and gearbox share a common lubricant.

• The combined engine/transmission layout places extra demands upon the oil in terms of extreme pressure
requirements for gear protection along with ball, roller and needle bearings incorporated into the gearbox.

[MiniMonty]

1) Stop saying "oil" and start saying "lubricant".
2) A 20w mineral oil will not run round your small bore engine on a February morning. It's syrup. It's like squeezy honey.
If you don't belive me try opening your sump plug at anything around 1 or 2 degrees Centigrade and them wait for your 20w to
gloop out like molasses. Try it...
In a small bore engine it will take 20 minutes for this oil to become fully viscose.

For the next four months you should run with 15w/40 or even 10w/40 synthetic and when the weather warms up again - do
nothing. A small bore engine always needs a slipperly thin lubricant - and the synthetics are a thousand times better
than the minerals.

What most people don't know is that lubricants are the very last thing made from a barrel of oil. They even scoop
off the last few petro-chems to make vaseline and plastic bags before they make lubricants. Mineral oils are rubbish made from rubbish.
Literally scraping the barrel...

The whole reason the synthetic lubricant market exists is that racing teams and top marques started to look for
better ways to lubricate high class million dollar engines. "Oil" is fairly good but a purpose designed synthetic lubricant
is much, much better.

You can easily fall foul of a lot of nostalgia around here on the basis that the A series engine is an old design and therefore needs old things
to help it work well - utter nonsence - any machinery with moving parts benefits from the latest technological advances - in lubricants,
or anything else. A brand new Aston Martin won't have ever seen a drop of mineral oil anywhere near it.

You wouldn't put 1959 anti-freeze in your radiator would you ? In favour of the latest generation of "cannot-freeze" coolants ?
Of course not. Same story on lubricant.

Case solved.

Best wishes
Monty

[rozzer1275]

I agree with minimonty, but can you clarify for me, isnt a 0w 50 the same viscosity at 100deg as a 20w50 if so why would you bother using 20w50 are you not just making things difficult when with a cold engine.

I know a mini hillclimber and he uses nothing but synthetic.

[Strontium Dog]

I've argued this MANY times! The only problem I can see with using synth is when it is used on an old engine that has been run on mineral oil. It is possible for the new oil to react with some of the seals and may cause leaks.

Synthetic oil at the correct grade is the mutts nuts. I run 300bhp from a 2liter engine and I use synth in the engine gearbox and diffs. My bike is 145bhp and shares it's oil with the gearbox and again I use a synth oil with NO problems whatsoever!

If you do change to synth then use an ester based oil not a cheap hydro cracked product and flush all the old oil out first. Be prepared to change some seals too.

Opie oils will give good advice and can recommend an oil for the mini to cope with the combined engine gearbox setup. check out the link below.

http://www.opieoils.co.uk/

[taffy1967]

Well I think we'll have to agree to differ on this one as I've been using 20W/50 classic mineral oil in my Mini for over a year and it starts up fine on a cold January/February morning.

Plus it's been proven by many Mini owners that this type of oil will help see a Minis engine/gearbox go the distance and I've heard tell that one regular 'Italian Job' charity event entrants Mini virtually went around the clock twice before needing any mechanical attention (i.e. gearbox work) and all he ever used was Duckhams Q Classic 20W/50.

So that's proof enough for me and the vast majority of Mini owners will tell you that synthetic oil is bad news for Minis.

But the choice is yours folks.

Edited by taffy1967, 26 November 2008 - 04:04 PM.

[lrostoke]

Never understood why synthetic is bad, I know on motorbikes I've always used 10w40 top notch oils , and you are talking high revving combined engines and gearboxes.
But saying that I do use Duckhams 20/50 in the 3 minis in our little group and all do around 8000 miles a year all weathers, no problems with gears or starting.

[taffy1967]

You wouldn't put 1959 anti-freeze in your radiator would you ? In favour of the latest generation of "cannot-freeze" coolants ?
Of course not. Same story on lubricant.

Well I wouldn't put that OAT type antifreeze in my Mini, no I'd stick with Glycol based instead.

Likewise I always use either Unipart or Lockheed DOT4 brake fluid, as opposed to the silicone based stuff that most motor factors stock now.