Best engine oil for an m20

[jonny323i]

Iv read the zones wiki and im still not sure which engine oil to go for as i will be buying some soon and want to get the most benefit form the ecp 25-30% off on oil etc.
Normallly i would just go for castrol gtx 10w40 which i can get for £13.99 for 4l
But the zone wiki recomends a 5w40 fully synthetic. Iv seen mixed reviews on fully synth in an m20 and iv also seen the option for 10w60 or 15w50 which surely would give a greater range especially as m20s do like to run a little hot especially in summer (if we get one).
So what would you guys buy

Ps iv seen alot of people recently talking about using a diesel oil in the m20 whats that about

[Brianmoooore]

Diesel spec. oil in an E30 is just for a short time to clear sludge from the engine. Flushing oils can do more damage than good, as they can dislodge deposits of sludge that have been sitting in some corner of the engine for years, harming nothing, and allow the to flow into a bearing or somewhere else that sludge is not a good idea. Diesel spec. oil contains high levels of detergents, which can gently clean your engine.
A M20 in summer should run at exactly the same temperature in summer as it does in winter - the temperature stamped onto the thermostat. If yours runs hot, then a cooling system overhaul is in order, probably centred around a NEW radiator.
A 5W-40 full synthetic oil is the best oil for any M20 is good order, but that doesn't mean GTX 10W-40 isn't an adequate oil.

[mr_dink]

I'd say fully synth is overkill and I used 10w40 semi synth when I last had an e30.

The diesel oil thing was to do with noisy tappets on m40s I think, it was suggested that the extra detergents in diesel oil might help flush them out.

I don't think there is much difference in diesel vs petrol oil any more, it's often labelled as being for either.

Might be worth checking with other local motor factors if you have one, I paid £18.99 for 5l of Comma fully synthetic for my Audi.

[jonny323i]

Mine never goes above half way on temperature I just think m20s have a higher running temp than some other cars I'm used to.
So I can either be a cheap skate or spend a little more but both are as good

[jonny323i]

Mine never goes above half way on temperature I just think m20s have a higher running temp than some other cars I'm used to.
So I can either be a cheap skate or spend a little more but both are as good

[Ajsingh]

Iv always used 10w40 castrol oil and it works perfect!

[maxfield]

I used Motul 300v 10/40w on my last service, very expensive oil but it is a good oil. Probably overkill for an M20 mind.

[andyp]

ive used 10/40 gtx for years and its been great.

[zaust]

Depends on weather this is an early high comp or not and also hoe many miles on the lump.

[jonny323i]

100,000 facelift low compression

[capri_rob]

Think I've always used 10/40 or 15/50 in M20's - my rule is buy cheap but decent quality stuff and change it often with a genuine filter. Carlube or the Triple QX ECP stuff is fine and its cheap enough that you can change it every 6-12 months without breaking the bank.

[zaust]

Iv always used 10w40 castrol oil and it works perfect!

My preference too. Castrol classic 10w 40. Or on a high miler 20w50.

or I run bardhal oil when I can. Same specs.

[Chris_B86]

Mines always, (and I mean always from new) been run on Mobil1 5w40 fully synthetic. It's on 147k now and it runs sweet as a nut

[Andyboy]

Mine is on 297'000 and has had a regular mineral or semi synthetic in the 10 years and 90'000 I've had it. I use a 10/40 grade. Before I had it, it was given whatever BMW recommend as it was a main dealer serviced car although it had a dealer oil change in Germany in April 2009. I would imagine 10/40 mineral or semi synth.

[oomz1975]

Been using Kendall 20w50, the touring loves it.
Change it every 6 months & engine is on approximately 150k miles.

[HairyScreech]

Any 10/40 semi synth will be more than up to the job on a stock m20, the bearing area vs the power produced is huge thus the bearings don't see a lot of pressure.

[Brianmoooore]

The oil recommended by BMW for UK conditions is 15W-50, but that is a quarter of a century out of date. 10w-40 is adequate, and will save fuel over a 15W/50.

[Morat]

It's amazing how little oil these engines burn compared with later models when you think we're running them on thinner oil than spec....
!

[George]

I've always used 10w/40 Semi-synth, typically Castrol, either GTX or Magnatec.

I'm surprised that fully synth is recommended in the Wiki.

[Brianmoooore]

I'm surprised that fully synth is recommended in the Wiki.

Because it's an all round better oil. That doesn't mean that E30s won't survive quite happily on lesser oils.
Most of my fleet run on Shell Helix 5W-40 full synthetic, which cost me £3.88/litre, which is better value than any ECP promotion!
I buy this as a 5 litre can, bundled with a 2 litre free can, in French hypermarkets when I'm over there

[Mo13]

thoughts on Triple QX oil?

[jonny323i]

That's the stuff I'm probably getting its £19.19 for 5l with a free oil filter at the moment from eco

[Low_E30]

One with a sell by date a apparently...

[jonny323i]

??

[Low_E30]

^^ http://www.e30zone.net/modules.php?name ... c&t=235156

[jonny323i]

I'm sorry I havemt got the time to go through 6 pages

[Low_E30]

No need to apologise, skip to page 4 half way down