The oil doesn't thicken as it warms up. Read AWDmoke's post again.

A 5W40 oil ACTS like a 5 single grade oil when it is cold.

Once the 5W40 oil warms up it ACTS like a 40 single grade oil.

The multi-weighted oil does become less viscous (thinner) as it warms up, just not as much as a single grade oil would.

The larger the difference between the 2 numbers, the less the viscosity changes (the less the thickness changes) at different temperature levels (correct me if im wrong here). Have also heard that the greater the difference in the numbers the faster the oil breaks down as well so there is a trade off.

So as the car comes up to operating temp, the oil becomes more like the thicker 40 grade?

Which is what I and everyone else is saying?

Using lay terms of course since most people don't even seem to understand viscosity, shear layers etc.

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[COLOR="Gray"]550Nm off a 2L... Just wish it was in the dak dak...[/COLOR]

Yep,

Just the way you answered the question that it becomes thicker as it heats up was misleading. I read up about all this stuff last year and at first when i thought about it I thought the ratings implied that the oil thickens when it warms up and was like that makes no sense lol.

Interesting read in that link at top of the page, will have to find some spare time to read it all.

Flows like a 5 weight <100 degrees

But has the FILM STRENGTH (Protects like) a 50 weight when hot.


It's all to do with the mechanical shear resistance of the base oil & it's additive package (zinc, Moly etc)

P.s No oil gets thicker when it's hot.

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[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]

just for anyone that is interested, Mobil Super 2000 10w40 at super shit auto is $24, save about 10 bucks. Going to try this stuff, Mobil seems like a good brand.

I only use the car as a daily and most of the time on the freeway. Mods are basic, so i don't think i should bother with a fully synthetic. Also 5k oil changes every time for me

cheers

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98 gf8 Rip

Mobil 1 5w50 is on sale aswell when i bought it. save $10 aswell i think

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Version 6 STI - 295/400

i would love to go Mobil 1 5w50, just the price! Also that i don't have heavy mods + i don't constantly thrash my car, i think and hope that the Mobil 10w40 would be sufficient.

I called the distributor for Mobil oils, they can get any of the Mobil oils in a drum of 20L, which saves you quite a bit. 300L is the next size i think, that's a lot of oil

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98 gf8 Rip

I would say the next size would be 205L, the old 44 gallon drum.

At Subaru Wangara we use fully synthetic 5w-30 in all turbo cars, we use genuine Subaru, which is the same as Castrol Edge 5w-30, just in a different bottle.

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Its just the internet dude, its not real.
F.B. Racing
01 WRX (STI badged)
2010 XR5 Focus
06 Impreza Hatch 2.0i

i was using Castrol edge 5w30 before, but got told that there was a price increase on these. Also i wanted to try something different.

I had no issues using the Castrol, used it on my last 2 services and was a treat.

Not many people here have recommended royal purple? I have read somewhere here that there was a bad test article on it...

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98 gf8 Rip

also john, do you know a guy called Siddy or something, asian? He is an apprentice mechanic but might be qualified now.

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98 gf8 Rip