Oil grade SN vs SM

[EHVS]

Hi there,

I did an oil change today. The last few times I used 'Nulon Full Synthetic Long Life Engine Oil - 5W-30'. This time at the shop, without thinking too hard I grabbed a 'Nulon Hi-Tech Fast Flowing Engine Oil 10W-40'. It was on special and I thought WTF, it's the same Nulon full synthetic etc with a different viscosity (car has done 280,000km). Anyway after I changed the oil (and filter) I noticed that the new oil API spec is SM, where my previous services were SN oil.

Is there any drama here? I'm not gonna be losing sleep over it, but I hear SN has a better sludge resistance.

Side note: I've been very happy so far with the Nulon stuff in the alloytech.

 

[Tonner Matt]

I'll try explain oil API spec for you and how it's classification determines what oil to buy/use.

The API spec of the oil changes alphabetically for the newer formula/generation oils.
So if your car was designed to run on API spec SG oil and you have filled it with API spec SH, SJ, SM, SN there is no need to be concerned. Higher API spec alphabetically is fine.
What you don't do is use oil that is an alphabetically lower API spec like SD, SE, SF as this oil is not the best formula for use in your engine.
As long as you are using the API spec specified for your vehicle or a newer spec oil, you have nothing to worry about.

Now some people will probably disagree and say "It doesn't matter as long as you use the correct type and weight of oil"
Well, in an old VN with 600,000km's on it, it probably wouldn't matter.
But if it was your brand new VF SS you had just paid a hefty price for, I'm pretty sure that you would want to be using the correct grade/ spec oil, not some oil formulated for 25 year old technology.

# Please note that some of the API specs I listed are possibly not actual oil specs. They were merely used to help with the explanation.

 

[timmy201]

VZ owners manual says "Use SAE 5W or 10W/30 SL GF-3 oil" for V6 & V8

Click on Gasoline in this link. As long as you are using SL or newer you should be fine.
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