patrolman

what grade do you use
im just about to look for the best oil for my 02 sti prodive
i put 5 30 mobil1 full synth last time
just had a look around and a couple of race suppliers recomend 15 50
mobil 1 fully synth

Bubba po

Maybe for a race oil. Just put in the grade that your handbook recommends. It won't blow up.

New_scooby_04

iTrader: (4)

Of course I could mention that Mobil 1 is not a proper fully synth, but that would just be opening a can of worms......

Whoa, ha ha ha ha!!

NS04

flopsy

heelo mate ther are loads of threads on here about oil
grades and the right and wrong one, but the jist of it is
don't put fully synthetic oil in your scooby as it is to thin
use patially synthetic oil in like castrol gtx magnetec.
or mobil s oil mobil1 is to thin had it in my car for 2weeks.
and made it tappy and noisey,
chris.

Heple

Not sure i agree.

I'd put silkolene or motul FULLY SYNTHETIC in. I'm not gonna discuss the in's and out's of it as i'm no expert. Talk with "oilman" he'll give you some sound advice.

There's plenty of threads in the tech sections look at some of them they'll answer all your questions.

I use Silkolene Pro S 5w-40 in my 99 UK Turbo.

Craig

Bubba po

It's nowt to do with whether it's semi- or fully-synthetic that makes it too thin, you berk. It's the viscosity that you choose.

Bubba po

Strange. They recommend 10w 40. What made you decide you knew better?

Heple

Agreed.

Go get him Bubba

TREG

I use baby oil!

Heple

johnsons?

I've heard it protects more when cold.

Craig

Oldfella

iTrader: (3)

Bubba, I use Motul 300v 15/50 is this ok?

Bubba po

I dunno, I'm a joiner.

New_scooby_04

iTrader: (4)

Yep, that's a Proper fully synth 15/50 maybe a bit OTT esp with the cold weather if I understand it correctly, but I think as long as you take extra care to ensure the caris warmed up properly before extending it you should be fine.

Speak to an expert, i.e. not 99% of the people on here including me!!!

For what it's worth, I use Silkolene Pro S 10/50 in mine.

Ns04

Bubba po

Andrew Timmins

I was under the impression that Mobil 1 was one of the few real synthetic oils on the market. Not the hydrocracked group III oils many pass off as synthetic.

What leads you to say Mobil 1 is not a proper fully synthetic oil?

New_scooby_04

iTrader: (4)

You answered your own question- I think it is one of the above

The ony "real" fully synths (ester or PAO based oils) on the market that I know of are Motul, Silkolene Pro S and Millers IIRC.

Just to stress, there is nothing wrong with Mobile 1 though, if Subaru recommend that or Shell Helix then it'll be fine.

Give Simon (Oilman a shout for more info)

NS04

Andrew Timmins

This answers my question about is it a fully synthetic.
http://www.mobiloil.com/USA-English/...AQs.aspx#FAQs1

Just wondered why you thought it wasn't.

New_scooby_04

iTrader: (4)

>Mobil 1 with SuperSyn uses high-performance fluids, including polyalphaolefins (PAOs), along with a proprietary system of additives

I could be wrong, but I think you'll find the clue is in the wording. ?

I'm sure simon will be along to clarify for us.

I Did find this on an older post (Direct quote from Simon)

NS04

Viscosity Index Improvers.

An oils viscosity will decrease as the engine temperature rises. Viscosity Index Improvers are added to reduce this thinning. They are a key addative in the production of multigrade oils.

VI Improvers are heat sensitive long chain, high molecular weight polymers that increase the relative viscosity of the oil at high temperatures. They work like springs, coiled at low temperatures and uncoiling at high temperatures. This makes the molecules larger (at high temps) which increases internal resistance within the thinning oil. They in effect "fight back" against the viscosity loss in the oil.

"Shearing"

The long chain molecules in VI Improvers are prone to "shearing" with use which reduces their ability to prevent the oil from losing viscosity. This "shearing" occurs when shear stress ruptures the long chain molecules and converts them to shorter, lower weight molecules. The shorter, lower weight molecules offer less resistance to flow and their ability to maintain viscosity is reduced.

This shearing not only reduces the viscosity of the oil but can cause piston ring sticking (due to deposits), increased oil consumption and increased engine wear.

Like basestock quality, VI Improvers also vary in quality. The best quality ones are normally found in synthetic oils (Group IV - PAO / Group V - Esters) and it is important to understand that the less of these in the oil the better the oil will stay in grade.

Which oils require more VI Improvers?

There are two scenarios where large amounts of these polymers are required as a rule.

Firstly in "wide viscosity" multigrades. By this I mean that the difference between the lower "W" number and the higher number is large for example 5w-50 (diff 45) and 10w-60 (diff 50) are what is termed as "wide viscosity" oils.

Narrow viscosity oils like 0w-30 (diff 30) or 5w-40 (diff 35) require far less VI Improvers and therefore are less prone to "shearing".

Secondly, mineral and hydrocracked (petroleum synthetic oils) require more VI Improvers than proper PAO/Ester (Group IV or V) synthetic oils as they are less thermally stable to begin with and this is due to the non-uniform molecules in petroleum oils as opposed to the uniformity of synthetics built in laboratories by chemists.

Sorry for the long reply but it's important to put the viscosity gap into perspective.

Cheers
Simon

Jay Cartay

iTrader: (3)

Whatever happened to Duckhams, eh? Used to have ads all over the place!

Andrew Timmins

The previous generation of Mobil 1 was Tri-Synthetic which I understood to be PAO(group 4) and two other types of synthetic base stock which were classified as group 5(a catch all category for base stocks which do not fall under the first 4 and includes esters such as those use by Motul).

Not sure of the real difference between the Tri-Synthetic and the newer Super Syn Mobil 1 but I'm pretty sure that it still a fully synthetic oil. Unlike Millers which is Group III.

New_scooby_04

iTrader: (4)

Duckhams Hypergrade....it looked like Fairy Washing up liquid IIRC

Ns04

RB5_245

I use coconut oil, that way when I don't have a rag to hand when checking the oil I can just lick the dipstick and it tastes of bountys

M1BJR

Yes, and if its a summers day, smear it all over and lay on the drive for an all over glow by the time the drip tray is full

Jay m A

iTrader: (2)

I use Fcukhams 60w10.

Its a bitch to crank over in the mornings, and once warm does a great batman style smokescreen out the back

sgcooby

Yawn. These threads are so ****. Rather than trusting someone with a worringly geeky knowledge of oil why not trust the experts i.e consult subarus manual for nthe recommended grade of oil.

Graz

Nah much more fun to have a 10 page debate (aka slanging match) over it.

Anyway use Comma semi-synth or Halfords semi-synth, PSL says it's the stuff to use so it must be right. Paying over the odds for full synth is just silly.

(Note I'm being sarcastic Silkolene Pro S in mine)

scooby-stu2

A guy who does a bit of rallying told me this week to put 0 - 40w mobil1 fully synth, thats in a 99 turbo, but hey i aint no expert, just wot he told me!

P1 NUT

iTrader: (1)

If you go on to opieoils.co.uk or.com, they have an enquiry field that you type in the details of your car inc mods, type of driving/trackdays etc and they e-mail you back with a recomendation of what oil and grade you should use.
I have a slightly modded P1 which they advised me to use 10w 50 from silkoline. Whereas Rcm use 15w50 in all impreza's they service.
By the sounds of it, no matter who you ask you will get different opinions.
I am currently using Millers 10w60 for what its worth.

Nevetas

I use mobil 1 in the 911 turbo and the GT3, its what Porsche stick in.

In the Scoob I used Silkoline Pro (looked like ribena!)

patrolman

all these idea's of what goes and what dont made me smile.........