Best oil for 1996 model Euro E36 M3 Evo

[Euro_M3_Evo]

Hi all,

new to the site and have to say so far this has been a very very informative site.

Right, I have an M3 with the above spec it is a 3.2 Litre S50B32 engine as opposed to the American S52 spec engine, don't know what difference if any that will make to oil choice.

I have been doing a lot of reading about oil and have also spent a lot of time talking to different people that ar ein the field, most have been salesman so i have had to use my discretion when sifting through information.

What i would like to know is about esters. So far, from what i hve been told i am led to believe that Ester based oils are best for my engine as they are more shear stable and due to the esters/double ester and soem with triple esters in them they will stick to the engine internals on shut down, thereby providing a coating of lubrication upon startup which is the time when most wear occurs to an engine. Most of these ester based oils are racing oils for instance Silkolene Pro S, Royal Purple, Redline, Gulf Competition....

I have read a lot about Amsoil Signature Series 0W30 and would like to try this in my M3 Evo but am hesitant as i don't thnk it is an ester based oil. Also I have been told that the best grade is either 5w40 or 10w40 fully sythetic for my engine but when i look through my service history I see that main dealer has used 0w30 in my car (i'm assuming castrol slx (now called edge) as bmw are affiliated with them.

My car has also had Mobile 1 0W40 in it and last oil change I put in Royal purple 5W40 and could swear that the car feels less responsive on pickup than it did when using Mobil 1 0W40.

Can someone help wth regards to informing me if ester based oils are indeed better for the engine or if race spec oils are better for road cars that are driven in a spirited manner every now and then?

Many thanks

Kash

[TheMotorOilSite.com]

Sorry for being so slow to reply. The site has been a bit slow lately, since spam issues started really taking over. I don't have the time to sift through it all and approve/disapprove all the posts.

At any rate, Esters ARE very shear stable and MIGHT be a good choice for your engine. The big issue is whether there is much chance of water ingression into the crankcase. Esters are prone to hydrolysis, meaning the absorb water, which is a bad thing. This causes TBN depletion, acid build-up and corrosion.

so, if you live in a high humidity climate, drive short distances or the vehicle sits for extended periods between drives, this could be an issue for you and Esters would not be a good choice, unless you plan on changing your oil fairly regularly.

BTW - There is NO way that Royal Purple oils are Ester based, unless it's one or two specific oils from their line. If you look at the actual tech specs for their oils, it's just not possible. Their specs are horrible.

As for the AMSOIL, it is true that AMSOIL oils are not completely Ester based, but, unless none of the above listed criteria apply to your situation, that's not necessarily a bad thing.

AMSOIL does utilize a small amount of Ester in their basestock, specifically for the high temperature performance, stability and the polarity of the oil which helps the lube "cling" to engine components, as you suggested.

However, the bulk of the basestock is a blend of multiple PAO basestocks.

I think you'll find that, for the money, it's tough to beat the AMSOIL oils. As for which viscosity, I'm not sure what your vehicle calls for, but I'd stick with the viscosity recommended in your manual unless you have good reason to deviate from it. Moving one grade up or down (the last number of a multi-viscosity classification) won't be the end of the world in most cases, and there are sometimes good reasons to do so, but, moving up or down by two grades would be highly discouraged.

[Euro_M3_Evo]

Hi there,

thank you for the reply. Now i am sorry for the late reply, i had actually forgot I asked the question here. Yes, i have been driving many forums crazy with my "What is the best oil for my m3) questions.

Unfortunately the cars manual does not say anything with regards to oil grades it just give certifications Like api/ACEA A3 etc... a lot of which i think are now out of date as my car is a 1996 model.

On a daily basis (mon-fri) I drive a mix of motorway/highway and town driving, not really short journey's, even if they are i always try to make sure the engine has reached up to temperature before I turn it off (may seem sad to some ). The only time it sits is over night.

At the moment i am using Mobil 1 0W40. Most around here (UK) advocate 0/5W40 or 10W40, some 0W30 or 5W30. Main dealer for some bizarre reason are adament that it is Castrol TWS 10W60 even though this was designed for the E46 M3 and E39 M5 or all ///M cars that are post 2000 models, a lot of specialists say this oil is just too thick for the e36 engine and vanos unless tracking the car and you regularly see 130 deg which I don't. Even when pushing it on empty roads for about 30-45 minutes my car sits around the 90 deg mark. From my service history I can see that bmw main dealer has used castrol slx (now edge) in my car.

What I want to know is can i use a good 0w30 oil (some call it a heavy 30 weight) as i feel this will be best for fuel economy but at the same time and more importantly due to less internal friction will give fractionally more power and generally make the car feel perkier and easy revving. Is there a 0W30 oil that has good HTHS figures for the protection? TBC

[Euro_M3_Evo]

sorry, ran out of space.

I believe for my Engine BMW recommend and HTHS of 3.5 cSt @150C so is there a good ester based 0W30 that meets this please?

Does an oil have to be ester based or have esters in it to be good? Is there a difference?

I read that mobil 1 and castrol aren't true synthetics but group III hydrocracked oils, is this true?

I read in your post about tbn depletion,is this something i should be looking at and is it a case of the higher the TBN number the better the oil is for the engine?

Also, about Viscosity index number, is this also a case of the higher the better?

Sorry for the long annoying posts and questions.

Many thanks

Kash