39 replies to this topic

[racingbob]

about to change oil, what do people think about

the 15 - 40 for winter time not doing long trips

and what oil to use

[dennismini93]

what year is your car and what engine?

[freshairmini]

according to his bio, its a 1275. could be outdated tho.

[racingbob]

its an mg metro engine thats modified but not high revving

[jaydee]

I sometimes use Castrol GTX 15w40, i prefer a 10w40 synth (diesel oil) for tough winter (snow etc..) plus i'm not a fan of the 15w40 viscosity grade..
When going for the GTX, i blend it with a SG spec 15w40 (ie Total GT1 or Elf GT both15w40) because GTX cointains moly. Being a friction modifier can cause problems with the synchros..lots of use it anyway. Its a quality oil, just dont use it for short trips as it really needs to warm up to burn contaminants.
What you want from your oil, is a suitable EP add pack (especially ZDDP - zinc and phosphorus at a minimum of 1200 ppm) so have a look at oil analysis before buying, its better than pub talk.

[dennismini93]

the idea of multigrade oils is for when its hot or cold. Rover recommended 10-40 and even 10-30 on the 90's cars but some people say use 20-50. mine ran better on the 10-40 in the winter than 20-50 but thats only in my opinion but might help? 15-40 shouldnt harm i gess??? iv also been told semi synthetic is better than mineral for a mini but no idea why so cant suggest nething for that one.

millers is a very good oil. i used castrol gtx semi synthetic 10-40 in my '93 1275 and it seamed to run better than on the halfords equivilant and better than when i tried the mineral 20-50 in my other 1275, was cheaper as well. castrol do mineral as well but halfords mineral is also supposed 2 be good?

i know its not directly answering your question but hope it helps

[jaydee]

Use a semi-synth 15w40 or 10w40. Or a full synth. Anyday.

[tiger99]

DO NOT use a synthetic or semi-synthetic oil in a Mini, as it is totally unsuitable for the gearbox, which shares the engine oil. It may seem to be ok for a long while, but then the gearbox or diff will fail prematurely. GTX or Millers Classic or similar is the stuff.

Most modern oils, even non-synthetic, are unsuitable for gearboxes as the shearing action of the teeth actually chops up the oil molecules. The contact pressure between gear teeth is far higher than in big-end or main bearings, and it makes sense to only use oil which has stood the test of time in Minis, or which was specifically recommened by the manufacturer.

Oh, and the proper oil is cheaper too.

Edited by tiger99, 01 December 2012 - 07:20 PM.

[racingbob]

no as you say i dont want a semi or sythentic just a 10 -40 or 15 -40 mineral if there is one

just for winter use, i normally use castrol 20 50

[dennismini93]

DO NOT use a synthetic or semi-synthetic oil in a Mini, as it is totally unsuitable for the gearbox, which shares the engine oil. It may seem to be ok for a long while, but then the gearbox or diff will fail prematurely. GTX or Millers Classic or similar is the stuff.

Most modern oils, even non-synthetic, are unsuitable for gearboxes as the shearing action of the teeth actually chops up the oil molecules. The contact pressure between gear teeth is far higher than in big-end or main bearings, and it makes sense to only use oil which has stood the test of time in Minis, or which was specifically recommened by the manufacturer.

Oh, and the proper oil is cheaper too.

rover recomended semi synthetic in the last decade tho??

[jaydee]

GTX is semi-synth.
I cant see why the gearbox will fail with an easter based oil...if so all the oil industries are in total fail developing synth gearbox/transmission oils.
Its moly that cause gearbox problems.

Edited by jaydee, 01 December 2012 - 07:38 PM.

[tiger99]

Wrong! The specific gearbox lubricants ALL incorporate some kind of extreme pressure additives which are not present in most engine oils. The industry DOES know how to make good gearbox oils, but you can't use a GEARBOX oil in a Mini as it does not have all the vital additives needed in an ENGINE oil. You need one that does BOTH, which is not common now as the Mini is an irrelevance to the big oil companies. Many manual gearboxes actually now use ATF, but it will last all of 5 minutes in an engine.

I have yet to hear of a gearbox actually being damaged when using any moly additive EXACTLY as per instructions. But you can't use one in a Mini unless it is suitable for both engines and gearboxes, which again they are not. Very many people used to use Molyslip in their RWD cars without problems, but you got different products for engine and box.

[mini-luke]

Anybody considered using bike engine oil? They share it with the gearbox too

[jaydee]

Mate, i totally disagree with this, the only problem with the ester based oils, is that they could make cause shrinking of the old abused rubber seals.
Millers specific mini oil is semi synth, castrol GTX is semi synth, valvoline too etc
Industry have moved on...theres no proof that a synth oil can damage a gearbox.

And the additives are the same, we're talking about zinc, phosphorus, boron and calcium....maybe the sulphur will differ which is not great for the engine.

Edited by jaydee, 01 December 2012 - 10:42 PM.

[jaydee]

Anybody considered using bike engine oil? They share it with the gearbox too

You'll struggle to get a good bike oil mineral based..