MC76

With so many on the market which engine oil would recommend for an import sti 97?

Thanks.

The rookie

iTrader: (1)

Any good Synthetic to API SJ or better...personally I prefer Mobil1 having seen testing where there was severe sludging on other oils when elevated to turbo temps (150C) over time, the Mobil1 didn't, although this was about 5 years ago, Castrol Edge or the Millers both have a very good rep.

Mobil1 for Euro28 for 4.5L in Auchan hypermarket Calais!

Simon

MC76

Thanks.

Mobil 1 seems to be a popular choice as far as i can see. Is 0w-40 a good safe standard? Obviously it gets quite hot but the car is not used regulary. One last thing, should it matter what is in there now when i top it up, it doesn't appear to be that full anyway?

scoobycraig

millers 10w-40! Always used it

tsl202

CASTROL EDGE RS 10W60!!! never had a problem with!!

V5RLTD

iTrader: (5)

Millers 10 40 in mine

Mocom Racing

iTrader: (2)

No - do not use anything less than a good quality 10W40, something like Millers or Motul should do the trick

Deano_P1

Millers CFS 10W40

andythejock01wrx

Silkolene Pro S.

marks1

iTrader: (2)

hi just wondered if youve used silkolene fully synthetic in your gearbox ??

The Fresh Prince

Anyone use motul 300v? Thats what I used to use, but probably going to use miller from now on.

Sc0oby

royal purple or motul

Alan Jeffery

Interesting one to watch with a new Scooby engine.
Don't put synthetic oil in it to start with! they just won't run in properly.
Cosworth say 3000 miles on mineral oil.

Mocom Racing

iTrader: (2)

Don't they also suggest a Subaru block with their rods/pistons will run over 800bhp

Agreed synthetic oil shouldn't be used whilst running in but it shouldn't be taking that long, the engines we build get Motul 300V fully synthetic by the time they've covered 1000 miles.

saxx

iTrader: (5)

i used 0/40w mobil one oil and just under a litre of lucas stabiliser. gives excellent protection.

i also put some in my gearbox too.

i was running a 1996 impreza wrx on standard internals, rolling road tested 317 bhp with a standard td05 turbo running at 1.3 bar and was suffering boost creep in 3rd 4th and 5th pushing 1.4 bar. i used to thrash the ***** off my scooby including many launches on my local racing strip... not once did i have any engine or gearbox problems. if anything my clutch took a beating and could have done with replacement before i sold it..

moral of the story... lucas oil stabiliser is very good stuff

The rookie

iTrader: (1)

I would really like to know your explanation for that really poor bit of advice! Do you actually know waht the numbers mean?

The W numbers refers to viscosity cold (below 0C), which is always at least 20 times the viscosity hot, for better cold running at low temperatures, faster oil circulation and better fuel economy, use the widest band you can, evertything else being equal always get a 0W over a 10W!

Simon

Torben

Mobil 1 5W-50 or Castrol 10W-60 as I use my self. It can handle any beating on street and track. It offcause depend on how hard you drive your car.

Alan Jeffery

I mentioned Cosworth to demonstrate how some feel about the running in period, and recommended oil types. We wouldn't use synthetic oil from the off, but we have heard of what can happen with those who have.
Whatever floats your boat!

bushiwarrior

millers

Mocom Racing

iTrader: (2)

I am sorry Simon if you feel that I'm offering poor advice in answer to a MC76's question, but I shall continue to 'offer' my knowledge and recommendations in an attempt to ensure Subaru owners get the best from their cars.

From the catalogue of engine failures that I've had the pleasure of dealing with, a high proportion have been bigend bearing failures and a majority of these bigend failures have been as a result of detonation - as I'm sure you're aware this can be caused by incorrect tuning, poor quality fuel, poor choice of aftermarket modifications, MAF failure, and the list goes on.........Detonation causes massive shock loadings, I'll let you work it out what components within the engine take the brunt of this.


In answer to your question to me, I believe I do have a fair understanding of oils but ask your self this, will a 0W40 offer the same bearing protection as a 15W50

The rookie

iTrader: (1)

If we go back to 0W40 versus 10W40 (as you suggested above), then catergorically YES, the hot rating (100C oil temp) is the same (40) the cold viscosity is massively higher (hot viscosity for a 40 grade is 20mm2/S), cold (I will use 0C as a typical UK winter day) 0W is about 1000mm2/S while 10W is about 1200, so the bearing protection cold is ALWAYS much better than hot, and the thinner 0W oil will get to the bearings faster from a cold start, so actually potentially offers BETTER bearing protection!

If you want the better protection (but worse power and FE due to increased friction) hot of a 50 grade oil, then your starting from a new baseline!

Simon (Rook B.Sc Engineering (mechanical))

Jay m A

iTrader: (2)

Simon, are you aware that Subaru IM do not reccommend Mobil1 0w40 for the classics? In fact Mobil1 produced a 5w40 specifcally for classic Subaru engines.

I believe they now suggest 0w30 for the Newage.

renno rannes

Motul 300v 15-50

The rookie

iTrader: (1)

I wasn't, there is no reason why the grade would cause a problem, so its more likley something else was changed (additives, friction modifiers etc etc) and they changed the nominal grade so they could track which oil was which....

Thinner oil for better FE I expect!

Simon

dabow

iTrader: (19)

i would say use a min of 15w 50

a turbo will kill all ?w/40 oils due to heat
i use Silkolene Pro S 10w/50

TonyBurns

iTrader: (3)

10w40 shell helix semi synthetic, as per the manufacturers recommendation.
All those who say fully synth, yes in part I agree, but if the car has never been run on fully synth and has 60-70k miles on the clock then there is no point in putting it in as the engine already has wear in it that the fully synth would reduce.
Just do regular oil changes, thats the best advice

Tony

Mocom Racing

iTrader: (2)

Simon (Rook B.Sc Engineering (mechanical))

what effect do high shock loads have on the hydrodynamic film around the bearings? Surely a 15W50 will provide greater protection

The rookie

iTrader: (1)

Dabow - at high temp oil thickens due to carbon build - so having 50 grade or 40 grade makes no odds its the temp resistance of the oil to coking thats important!

MR - Yes a 50 grade generally will, and thats EXACTLY what I said I think?

"If you want the better protection (but worse power and FE due to increased friction) hot of a 50 grade oil"

Simon

Scoobyfirsttime

Last time I topped up I used semi 5-30

Am wooried now that this offers no protection from what Mocom are saying.

andythejock01wrx

Dunno, but the handbook for my 01 WRX recommends it.

This subject confuses me somewhat. I have Silkolene Pro S 5w40 in my car, as recommended by The Oilman, but some peeps seem to think it's not up to the job.