Best engine oil for the RX8 231?

[kopite72]

Yeah I use millers all the time but just wondering if the nano drive stuff is OK...

[AndyBrad]

i think realistically what this thread is suggesting is basically any oil will be fine of a similar grade

[Dazza44]

Yeah I use millers all the time but just wondering if the nano drive stuff is OK...

I use millers nano drive(allways have in mine)and was recommended by bigpete.

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[kopite72]

Thanks Dazza

[warpc0il]

I started to reply to this thread but my answer become more appropriate to add to the FAQ - here
viewtopic.php?f=25&t=50814&start=4

[bigpete8]

Cheap and cheerful and change often is my approach.

[Freeman38]

I use Millers CFS 5/40 NT which is a fully synthetic is the only one I use in my RX8, have done for 10 years now and no issues.
Previous to that in RX7's I used Millers 10/40 CFS, there was no nano tech back then.

[dac69er]

Cheap and cheerful and change often is my approach.

Same here. Changing more often has more benefits than more expensive oil imo.

[sKenDread]

I've been using Petronas with a shot of molybdenum. Mines on its way out though. I would think but it's quiet as hell compared to before adding the molybdenum.


08 231 West Midlands

[sKenDread]

Solid additives, such as moly, are not a good idea for a rotor.

The OMP is unique to rotary engines and the feed hole to the reservoir is tiny and easy to block.

The reservoir also acts like a sump and will fill-up with sludge.

Most additives are designed to resist burning and/don't burn cleanly - which would create more problems.

All assuming you're not running a sohn/Cofs.

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[sKenDread]

I know I'm going against the grain on this. I'm sure miller's nanodrive has moly aswell. I'd be concerned if it was tungsten or graphite based but I don't know a lot and only have self earned degrees of Google addiction and keyboard warriorism

I'm just interested in seeing the effects it may have.

Having said that, I ran a stock FC turbo with another moly brand additive. A lot of people gave me flak for it but I kept using it for 7 years (10k per year) 120k on the clock. It did have hot start problems before switching oils. That obviously didn't go away but it definitely had less vibrations than before the additive.

Oh I did fit an OMP adaptor too


08 231 West Midlands

[RenesisRaceBuggy]

Nanodrive is tungsten buckyball based, and most moly additives are the powder form in a cheap kerosene or light mineral oil - which does nothing but block the oil filter and degrade the detergent and despersant addivitives already in the engine oil - moly in oils is already there in the green soluable form.

[sKenDread]

Interesting man, I'm surprised Millers chose tungsten over moly... I mean from what I've read, tungsten shows better results as a friction modifier. But the biggest problem I remember from the beginning is failure to keep tungsten in suspension. The stuff would drop to the bottom of the sump.

Maybe Millers have worked out how to keep it suspended. Molly doesn't have this issue. Makes me wonder if they are blending the 3 friction modifiers.


WHOA! WOW! TO THE OP....
Don't follow in my steps man! I have no proof why my FC lived a long life. And I'm fully aware of the ramifications messing with OIL101. These dude's in this thread really know their stuff.



08 231 West Midlands

[RenesisRaceBuggy]

It stays in suspension because the particle sizes are so small - around 5nm IIRC for their add pack. The reason it still works okay in plate diffs and synchro boxes is because if they pull the other EP additives the tungsten is small enough to fill in asperities in the surfaces without bridging over them and basically sitting completely between the surfaces and preventing the friction plates/syncros from doing their job, but will still reduce wear.
It has moly, phosphor and zinc in there too as they all do other jobs, and even some of the newer boron nitride based friction reducers - but the tungsten is the main wear reducer.
Moly doesn't have an issue if it's 'green' soluable moly compounds - it does in the common black/grey cheap powder form that most Snake Oil additives have in there.

[sKenDread]

This is why I do like the Oil conversations. It gets tiring seeing the same question pop up all the time but I would like to think that we are following proven recommendations and with time, tests, tech etc... those proven recommendations would also be improved upon.

I like to to see trial and error results. Challenging and testing has the potential to change our recommendations or make em more grounded. Just like using 0W as opposed to 10W. I still haven't seen any written proof that 0 viscosity is far too thin for a rotary and the safest bet is to go with what the Pro's recommend.

[sKenDread]

I don't *think* 0W as in 0W40 would be too thin for a rotary, as it's the second part of the description that defines the viscosity when hot, the first part is the cold performance - IIRC.

The potential issue is that to create an oil that has the scope of 0W40 requires a synthetic base rather than a mineral base, and that gets us into the issue of burning synthetic-based engine oils. Engine oil aren't designed to burn, unlike 2-stroke oils, and synthetics can leave hard carbon deposits which damage rotary internals.

If you're running a sohn/cofs then I see no issue with 0W40 in the engine but I'm happy to be corrected.

[ChrisHolmes]

Or even 0w60 as in my M3s V8 !!

[plas87]

Opinions on the Euro Car Parts Triple QX 10w40 semi synthetic oil?

What about ester based oil, are they worth it for the rotary engine?

[ChrisHolmes]

We use that and have no issues

[Billsrx8]

I ask a few experts on the forum and they said the specs of this oil is fine.. £38 for 20ltrs so it what I'll be using and changing regular.. https://photos.app.goo.gl/JjSj9mhvY9Vicmc88

[untakenname]

Anyone using a SOHN should use synthetic in the sump imo as the benefits over mineral have been proven on piston engines when it comes to big end wear.

I used to use Miller's 10W40 and now use Shell Helix Ultra 5W40.

[plas87]

I had an oil and oil filter change at the garage using Triple QX 10w40 only 4 days ago. They drained from the oil pan which only holds around 4 litres but I know the total oil capacity is 8 litres. So today I got myself another 5 litres container of Triple QX 10w40 oil and used a siphon pump to extract circa 4 litres of oil and topped up.

[*thomas*]

Just went trough the majority off this thread looking for a simple answer, turns out there isn't. The internet is littered with different opinions concerning oil for our cars and even shops can't seem to agree on what type of oil to use. What baffles me most is that the three UK shops that pop up when using google or doing research state three different things.

Shop 1: 15w40 (mineral)
Shop 2: 10w40 (SS)
Shop 3: 10w40 (SS) unless you upgrade the oil pressure regulator, you can go back to 5w30...

Like some have stated, I agree 5w30 is too thing and was done to meet emissions (while not always beneficial for the engine, lots of other brands have done the same thing).

To my understanding, mineral oil will burn cleaner and leave less residue but will need more changes (in theory).

Can I therefore summerize that when it comes to mineral vs SS it's about reducing carbon build-up vs increasing bearing longevity?

[kopite72]

Don't overthink it,just use Millers 10/40 SS,Rotary Revs recommend this oil and thats plenty good enough.I used it for six years with zero issue

[*thomas*]

Don't overthink it,just use Millers 10/40 SS,Rotary Revs recommend this oil and thats plenty good enough.I used it for six years with zero issue

Ok, wil try not to and go with some 10w40. Thanks.