Engine Oil for the S2000

Motul 8100 series is the way to go :-)

got a 6L of nulon 10w-40 for 60$.. supercheap had 5L for the same price so why not!

also went to Honda and got some mtf-06 for when I get my new clutch fitted

Oils get thinner as they get warmer. The numbers in the viscosity rating is not an absolute viscosity measurement. They are relative to the standard single SAE rated viscosity oil.

So a 5w-40 for example means that at -18ºC, the oil has the same viscosity as an SAE5 oil at -18ºC. It also means that at 100ºC, it has the same viscosity as a SAE40 oil at 100ºC. This is why the 5w-40 is called a multigrade oil.

If you take the oil spec sheet of any engine oil, it will tell you that. For example, here is the spec sheet for Motul's 8100 5w-40 oil. http://www.motul.com/system/product_...%205W40_GB.pdf

If you look at the viscosities measured at 40ºC and 100ºC, the 40ºC viscosity is already much much thicker than the viscosity at 100ºC. If you were to compare the -18ºC value (which is not mentioned in the spec sheet), that would be even thicker still.

Quote:

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Originally Posted by AusS2000

Then please explain what the two numbers either side of the w mean. Is it not true that the higher the number the more resistance to flow (internal friction or viscosity) hence using 20w50 in older low revving engines?

My understanding is that simple fluids decrease viscosity (get thinner) with temperature fairly linearly. Hence traditional oils have a single viscosity number. Friction modifiers were introduced as a clever way of reversing this trend for a range of the temperature. Ah the wonders of modern science.

Happy to be re-educated.

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The W signifies that the preceeding number is the cold specification of the oil. The second number is hot grade.
They are not directly referring to viscosity although you can compare first and second numbers between oils. as in 5W-30 and 10W-30 have the same viscosity at high temp but the 10W is thicker at start up.
aaronng explains better.

Thanks for clearing that up. I learn something new everyday.

I use Royal Purple 5W30 Fully synthetic oil, pretty pricey but great oil.

Royal Purple 10W - 40

Hey guys, I'm looking at trying another brand of oil, because I'm over paying $90 for oil lol.

Thinking about Fully Synthetic:
- Mobil 1
- Nulon

both around 10w-30/40 whatever they come in. Any reccommendations on which one to choose over the other???

I'd have a look at Penrite HPR 5, which is a 5W-30 specially developed for modern variable valve timing engines.

Penrite do formulate good oils.

Ive used Nulon 10w-40 for my last oil change a couple on months ago. Great oil, just bought another 6L bottle two days ago. Has anyone ever used Wynns Engine Flush? I know a few mechanics use this to rid the gunk build up in the engine. Wondering if it would do any damage to ours...

I use a highly detergent diesel oil to flush out my ordinary engines. I usually run it for a thousand Km or so.

I have a highly tuned 4.6L rover V8 in a TR8. These are rather dirty engines which get a lot of carbon residue in their oil. I had been using Penrite HPR 5 in it, [5W-30high performance] & was happy with it, apart from the carbon on the inside of the rocker cover.

Penrite suggested HPR diesel 5, which is basically the same oil, with only more highly detergent.
After a couple of changes of that, you could use the rocker cover to shave, it's that clean.

I'd rather use a quality oil to flush my high performance engine, than something else, but that's possibly just me being paranoid.

So would there be any harm in just using the Wynns engine flush product?