What oil?

[IamFODI]

Castrol TWS is called a 10w60, but it acts like a heavy duty 40 weight from my research.

In what sense?

I know it used to shear down into the xW-40 range in service. Does it still? I remember doing some digging on this a few years ago and came to the conclusion that (then-)current formulations basically never sheared past the xW-50 range (min. 16.3 cSt @ 100º C).

[Feffman]

My 10W-60 oil spreadsheet.

Feff

[Tbonem3]

*PSA*

Talking about oil weights by using terms like 5w50 or 10w60 is almost useless. Just like tires - A 265 Michelin PS4S can be wider than some ling ling 275 tire.

Castrol TWS is called a 10w60, but it acts like a heavy duty 40 weight from my research. Then there's something like Liqui-moly 10w60 with a CST of 26+ at 100degress, which is about the highest I've ever seen, much higher than castrol or other 10w60s.

The "redline 5w50 instead of castrol 10w60" argument for S54/s65/s85 has gotten popular, but is redline lighter than castrol?

Well, 1st formula of redline had HTHSV rating of 5.9, newer formula is 5.0. Castrol is 5.3! Barely any difference. "ReDlInE is bEtTer in the CoLd!" Well, RL 5w50 has a cold pour of -45 and Castrol's is -39 so no.

Viscosity, Kinematic 100°C of Redline is 21, Castrol is 22.7, almost no difference.

You cannot conclude that redline is better for cold starts than Castrol just because Redline says 5w50 on the bottle and Castrol says 10w60.

Haven't even discussed additives. Perhaps Redline is low on additives because their product is meant for race cars. So even if redline and castrol were neck and neck in terms of viscosity and resulting oil pressure etc, Castrol could still be a better choice for most (Street cars) due to better/more additives.

Or maybe you have cats and don't want a race oil high in ZDDP? Castrol has other anti-wear properties that don't damage cats.

[enjoy_m3]

Already replaced it

Is it coming from the front of the engine? Could be the vanos rattle. I'm running lucas 5w50 on my street (convertible daily). Warms up quicker, no issues with oil temp, no noises, and no oil consumption. Car is mostly a cruiser though.

(I stand corrected by tbone)

[ac427]

Motul 300V 10W40

[Advorsor]

Idle control valve, clean it.

Already replaced it

[CrisSilberGrau]

Its always very loud and the revs fluctuate the first couple of second (30s tops) before it settles.

Idle control valve, clean it.

[IamFODI]

I’ll continue to investigate but those first 30 seconds or so are definitely more pronounced in the Winter months.

What kind of noise is it? Might be worth posting a separate thread.

[maupineda]

5w50 is the best compromise in my opinion. For a regular usage car, is best to have an oil that makes the engine run cooler and allows better flow during cold starts. 60 grade oil comes in need when wringing the car much and in hot conditions, other than that is overkill and perhaps more detrimental than not.

[EthanolTurbo]

Has anyone run Valvoline VR1 consistently and had a good experience? Was thinking 5w50. It's high in zinc, seems just right for an S54.

[Advorsor]

Doesn’t sound like an oil problem. It sounds like something else is wrong, e.g. an exhaust leak. Best to figure that out and fix it.

Switching to thinner oil might actually be worse. When an engine isn't running right, it'll usually dump a bunch of fuel and other contaminants in the oil. Thinner oils generally don't cope with that as well (there are exceptions but that's the rule).

I’ll continue to investigate but those first 30 seconds or so are definitely more pronounced in the Winter months.

[IamFODI]

Its always very loud and the revs fluctuate the first couple of second (30s tops) before it settles.

Doesn’t sound like an oil problem. It sounds like something else is wrong, e.g. an exhaust leak. Best to figure that out and fix it.

Switching to thinner oil might actually be worse. When an engine isn't running right, it'll usually dump a bunch of fuel and other contaminants in the oil. Thinner oils generally don't cope with that as well (there are exceptions but that's the rule).

[Advorsor]

What do you mean by sensitive? What's it doing?

Its always very loud and the revs fluctuate the first couple of second (30s tops) before it settles.

[IamFODI]

I’m thinking of changing out of 10W60.

My motor is a bit more sensitive to cold starts.

What do you mean by sensitive? What's it doing?

[eacmen]

Anyone running Amsoil on their race/track car?

https://www.amsoil.com/p/dominator-sae-60-racing-oil-rd60/

I’m on my last set of TWS and thinking of what to try next.