RB5_245

There was only a 2wd for the US market. All uk impreza's are full time 4wd to the best of my knowledge.

Dave

oilman

iTrader: (9)

Trust the US to be the only ones with a 2wd!!!

Cheers

Simon.

SomeDude

I'm 99 % sure I once had a 1.6 Impreza (1997) as a courtesy car that was 2WD.

easyrider

I havnt had time to go through the whole thread-Is there any conclusion as to what the best manf./grade oil to use??????

easy

oilman

iTrader: (9)

5w-40, 10w-40 or 10w-50 depending on application and use.

Which brand you go for is down to you.

As has been discused on this thread before, in my personal opinion based on technical data and facts is Silkolene Pro s 10w-50 ester based fullysynthetic.

Cheers

Simon.

oilman

iTrader: (9)

Just an article of interest about selecting the correct engine oil.

Surely the thicker the oil the better!

This isn't always true - even when using a petroleum oil. Although it is true that
heavier viscosity oils (which are generally thought of as being thicker) will hold up better under heavy loads and high temperatures, this doesn't necessarily make them a better choice for all applications.
On many newer vehicles only 0w-40, 5w40 or 10w40 engine oils are recommended by the manufacturer. If you choose to use a higher viscosity oil than what is recommended, at the very least you are likely to reduce performance of the engine. Fuel economy will likely go down and engine performance will drop.
In the winter months it is highly recommended that you not use a heavier grade oil than what is recommended by the manufacturer. In cold start conditions you could very well be causing more engine wear than when using a lighter viscosity oil. In the summer months, going to a heavier grade is less of an issue, but there are still some things to be aware of.

Moving one grade up from the recommended viscosity is not likely to cause any problems (say from a 10w40 to a 10w50 oil). The differences in pumping and flow resitance will be slight. Although, efficiency of the engine will decrease, the oil will likely still flow adequately through the engine to maintain proper protection. However, it will not likely protect any better than the lighter weight oil recommended by the manufacturer.
Moving two grades up from the recommended viscosity (say 10w40 to 10w-60) is a little more extreme and could cause long term engine damage if not short term. Although the oil will still probably flow ok through the engine, it is a heavier visocosity oil. As such it will be more difficult to pump the oil through the engine. More friction will be present than with a lighter viscosity oil. More friction will be present than with a lighter viscosity oil. More friction means more heat. In other words, by going to a thicker oil in the summer months, you may actually be causing more heat build-up within the engine. You'll still be providing adequate protection from metal to metal contact in the engine by going with a high viscosity, but the higher viscosity will raise engine temperatures.
In the short run, this is no big deal. However, over the long term, when engine components are run at higher temperatures, they WILL wear out more quickly. As such, if you intend on keeping the vehicle for awhile, keep this in mind if you're considering using a heavier weight oil than the manufacturer recommends.
The best advice is to is to stay away from viscosity grades that are not mentioned in your owner's manual.

Cheers
Simon

SomeDude

Interesting - as I said I am still on the fence.

Can you explain to me why my oil temps (which is not the same engine temps, I agree) dropped a few degrees after switching from 5W40 to 10W60 ? (about 4°C, not "gut feel", but actually measured). I know this for a fact, as I watched it happen.

Would that mean the engine is transferring less heat to the oil ?

Does this have any effect on EGT's ?

TonyBurns

iTrader: (3)

Oilman,
STi in Japan do their own oil which is outside of the viscosity of the manufacturers book (Its actually motul 300v 15w50 fully synthetic) so i would take it they have tested this oil in their engines and proved that it was ok for use?

Tony

krazy

Its not outside the manufacturers handbook, it states under severe driving conditions, SAE viscosity No.: 30, 40, 10W50, 20W40, 20W50

TonyBurns

iTrader: (3)

Cheers Krazy!

Tony

knap

Interesting article on ester chemistry
http://www.hatcocorporation.com/pages/about_esters.html

easyrider

Thanks Simon

sooby

easyrider,

Read the thread. There are those that don't rate the Silkolene Pro S oils.

johnfelstead

I am surprised you are still using this email as a basis to back up the use of Silcolene ProS in a turbocharged engine, and using it as proof of its abilities in a WRC rally car engine after i pointed out to you 13 days earlier on the SXOC BBS that the email was technically inacurate in terms of the failures Andy Burton was having (he was wearing the camshafts and valvetrain, not killing big end bearings) and the fact it is a very specialised Normally Aspirated DTM engine built by Cosworth for the works Opel team that Andy uses in his rally car, a very diferent animal to a WRC Turbo engine.

Using the results you had with Andy's NA DTM engine has no relevance to a Turbocharged production car engine IMHO, there are very difierent problems to address, in the case of Andy's a very high reving 420BHP V6 race engine with high lift cams designed to last the course of a DTM race between rebuilds, not consecutive 100 competitive mile special stage rallies.

Yes they used to sell a 2WD impreza in the UK, as they did in the USA, my pal jamie won production class rally titles with this before moving up to a WRX. One of the issues she found when going to the turbo WRX was the oil spec required, she needed to run higher viscosities to stop oil vapour contamination problems under such harsh turbo conditions. Running in a production class she couldnt use external breather systems to allow for excess vapour encountered with the lower viscosity oils so changed the oil, which cured the issues.

Oil choice is a complex area, what works for NA doesnt always work for turbo apps, especially when driving the cars hard. I will only use two oils in my turbo engines after years of trying to find what works for me, these are Castrol RS10/60 and Motul 300V 15/50. I am curently in the final stages of building a supercharged 300BHP engined car, for this i will be using Motul 300V 5/40, being supercharged the heat transfered to the oil is significantly lower (self contained lubrication system on the charger) which enables the use of a lower viscosity oil. I used to run the stock dealer spec oil in my Impreza Sport as the heat generated in that, even when driving it hard, was insignificant.

The various blends of oils available from the Motul 300V range are there for a reason, for example they produce a higher viscosity of oil than the 15/50 specifically to counter the fuel dilution problems you see in a 24hr race, i wouldnt use this on a road engine because you dont have the same problems. I was recently helping in the pits at the nurburgring 24hr race for a friend who was driving one of the front running M3 GTR's, they finished 2nd in class, the oil used was castrol RS 10/60.

With regards to gearbox oil, the syncros in the subaru gearbox are designed specifically to anable a higher viscosity of oil than a conventional manual transmition because they share the same oil as the front diff, using a conventional MT oil will not work. I have found very good results using Redline Heavy Shockproof in the gearbox and rear diff on my STi, especially so on track where i used to get problems with heat making the gearchange tighten up after a few miles of hard driving. Redline lowered temperatures significantly and kept the gearchange silky smooth.

sooby

johnfelstead,

Don't you read your private messages or email? I've been trying to get hold of you!

johnfelstead

yes i do when i can, not been home much for 8 weeks so catching up slowly.

SomeDude

FWIW, even I get this even with Castrol Syntrax, and I must be about the slowest track driver ever.

Do a few laps, and sometimes it just refuses to get in to the higher gear.

I used to think it was me being clumsy as always. I *am* clumsy, but that's not the reason why the gearbox suddenly seems to lead a life on it's own.

oilman

iTrader: (9)

With a thicker grade oil there is heat generated by friction pumping the oil. If the oil is not so thick, less resistance, less friction, less heat.

Cheers

Simon.

StickyMicky

correct

sooby

Oilman,

That doesn't explain SomeDude's experience.

SomeDude

But sooby...

1) I must have dreamt it
2) my gauges are all wrong
3) I'm lying
4) I'm hallucinating
5) I have about 10 IQ.

Simon, if you don't come up with better stuff, I'll continue to use this dreaded 10W60 oil and call you an ordinary sales weasel. Mind you, my car only did 145.000 km on this oil (and still going strong...). I know I know, one car doesn't change the world, but still, it was/is seriously tuned, and didn't miss a beat.

You are starting to ennoy me TBH. Lot's of babble, no real world experience. What a surprise

We want *beef*, not opinion.

Have you ever driven a tuned Subaru ? Have you ever owned one period ?

Talk to me, don't hide beyond "esters" and all that ****, I don't understand. I'm sure you wouldn't understand how to play a twelve string, or how to maintain an established Koi pond, or how to program in Pascal. Still, I would be able to *get the message out*, you so far have only been dodging the inevitable "get a banner ad" comment.

Talk to us, don't play the ****ing oil hero.

My oil temps went *DOWN*, not up due to an astmathic oil pump not doing its job. READ FFS !

Theo (jumps off fence)

PS: cynical as I am, you may be right, but you fail totally to bring your point across. Think about that !

PS2: thanks Micky, I thought I was hallucinating. That stupid roundabout teached me otherwise

johnfelstead

Try the Redline Theo, it works for me and is a big help on track with gear selection.

Bob Rawle

Comment on temps, thicker oil (higher viscocity), higher pressure, lower oil flow (more resistance to flow), per unit has longer to absorb heat (slower moving), more temp ?

The Sti5 certainly runs marginally hotter oil temps than when using a 5-30 oil, the Sti9 has so far shown no diference at all.

However not a downside as long as you choose an oil that has a good viscocity index.

I get (on both cars) minimum oil pressure of 6 bar by 1700 rpm, try that with a 5-40 or 5-30, full oil pressure at 3000 rpm only !! (Talking FULLY up to temp here ie after 20 miles driving)

Further comment is 6 bar is the typical max on an average car so thats my benchmark, I actually see 7.3 bar pressure on the Sti5 (uprated engine and a testiment to its build) and 6.8 bar pressure on STi9 (std engine)

bob

MY99-5DR

Chill out mate, there are a number of possible explanations for your findings.

Firstly, it is possible that the 5W40(?) you were using originally had poor friction modifiers - additives designed to....here comes the science....reduce friction! Castrol RS10W60 is a fundamentally thick (viscous) oil, but it has excellent friction modifiers that help to make it flow more easily. I know that sounds like contradictory rubbish, but consider this real world example:

Take a few teaspoons of cornflour and throw them into a cup or mug. Add a small amount of water slowly and stir very gently to mix it as you're doing so. When you have what could be described as a runny paste, try stirring it vigourously. You should find that it's viscosity increases enormously to the point that you're in danger of bending your spoon/fork!! This simple experiment demonstrates how friction can affect the behaviour of a fluid. If you're now bored with the thick gloop in the bottom of your mug, stop stirring it and pour it out - suprise number 2!! As soon as you stop "working" the fluid, the gloop reverts back to a thin liquid !!

Secondly, it is possible that your original oil had thinned as a result of natural degradation (something that oils based on esters or those containing good quality viscosity improvers in sensible proportions tend not to suffer from), or as a result of contamination/dilution by combustion materials. Reduced viscosity will lead to a thinner-than-optimum fluid film between bearing surfaces and this can also generate excessive heat, plus you run a real risk of metal-to-metal contact & consequent engine bills.

Consider a second real-world example:

You're out on a beach on a scorching day and you're feeling energetic - you decide to go for a run (bear with me here...):

It is agony running on the hot sand - your feet are burning (no lubricant = dry running + enormous heat generation)

You run in 1" of water at the edge of the sea. It's better, but the sun is beating down and you're still too hot (inadequate fluid film, but no surface-to-surface contact)

Now you run in 2"-3" of water and it feels great. It's cooling but it's not slowing you down (optimum fluid film thickness; good lubrication, good heat transfer away from the hot bearing and minimal heat generation).

Happy with your efforts so far, you feel brave and venture out into knee-deep water - surely you can't get too much of a good thing?! Well actually you can... Running in knee-deep water on a scorching day is a recipe for a trip to a heart surgeon. (Oil is too viscous, the fluid film is too thick and rather than remove heat, it actually generates heat)

I hope you'll forgive me if you find the above patronising, it was the best explanation I could think of for what is a hugely complex subject area. Coming back to the original point about friction modifiers, I suppose you could assume that an oil with poor modifiers would be akin to your beach run being made in your finest pair of 70's flares, i.e. the same principles apply, but it's even harder to make progress.

Viscosity is not the only parameter to effect the performance of an oil, but it is crucial to get right; you can have too much of a good thing!

oilman

iTrader: (9)

Somedude.

I am sorry that I have not got my point across, I thought it was very clear.

The stuff posted here is technical but factual and yes, I understand that there is a real world out there however in the real world is it not good to have differing opinions and debate them? This should benefit everyone.

This thread has been read more than 3500 times, it must be of interest to many people and hopefully some technical information has been learnt by many people on the way. So people hopefully are better informed.

With regards to esters/pao's, real synthetic oils in the true sense of the word (and Castrol RS 10w-60 is unfortunately not one) they are better. I'm not hiding behind them, I sell all sorts of oils for all sorts of cars with different needs but the fact remains that if you want to do the best for your engine long term, you should consider them.

The debate here has been very interesting and there are clearly many brand loyalties. Fair do's, I really don't have a problem with that but as stated before, I do have a problem recommending an oil that in my opinion is not right for your car and this is based on factual data again.

I don't run a "scooby", I have an RX8. It's just personal choice, I've nothing against them, just never wanted one or many other cars for that matter!

Oil is also a personal choice and that's why I sell 5 brands including Castrol however it would be wrong of me to endorse the use of an oil that is not mentioned anywhere in the handbooks however, it's your car and your choice and I respect that.

I'm not here to fall out with anyone and have much interesting information that can be contributed which applies to the real world. Whether or not an ester 10w-50 is better than a non-ester 10w-60 is beyond doubt for me but I'm afraid that you will never know unless you try it.

Cheers
Simon

PS. MY99, great post, never considered oil in such an imaginative way before, that must have taken some good chemical background to relate.

dlynch

Well i have read this thread from start to finish...

I know very little about cars. Its got an engine and press my right foot on the throttle and it goes.




I am lost........

Basically am i OK to just let Subaru do what they want with my Oil?

Ta

Dom

sooby

My take on the subject - for what its worth...

Run your car in for 6k to 10k miles on semi synthetic like Shell Helix 10W-40 before switching to fully synthetic.

Amongst the preferred fully synthetic oils mentioned are motul 330v 15/50, castrol RS 10/60, Mobile 1 (not sure if this is fully synthetic), Silkolene Pro S and Red Line. If you choose a big name you're unlikely to have a problem. Shell and other do fully synthetic oils but their grade is not the choice of most people because the starting grade is too low (5W).

I have read about people being talked out of using Castrol RS 10W-60 because the end grade might be too high (60). Subaru recommend 10w30 or 10w40 unless you really stress your engine for example by towing a caravan. They suggest not to maintain high speed driving for a 10W30 grade oil. So, if you drive over to France and on some private roads (!) I suggest not to use this grade of oil. 10W-40 sounds a good compromise if you have a standard car and don't want to worry about warranties should Subaru check the oil grade after a blow up.

It now depends on how you drive, track days, and the mods you have on your car as to which one you choose - we're now assuming warranty is no longer an issue. I'm sure all the above oils have something to offer. One will be better than another for your car, it's setup and your driving habits and may be demonstrated by lasting longer before breaking down than another. Keep an eye on the colour of the oil, the smell, and rub some between your finger and thumb - these three tests give you an idea of how 'happy' your oil is. Change the oil if in doubt - don't wait for 7.5k or 10k miles to clock up first. Many people unconditionally change their oil every 3k mile. There are some friendly garages that will be happy to do your service and give you the service stamp even if they leave you to change the oil. This way you can be sure to top up the filter first etc and put the right amount of oil in. My garage does but informs me that it shouldn't be necessary for me to pay the kind of attention I do to the oil as they've had many cars go to 140k on their BP Visco oil. My car is standard - I love it as it is. Some garages are happy for you to provide the oil for the service.

I don't do track days but understand that the oil should be changed directly before and directly after a track day - even with the best oils.

If you want to leave it to a garage to take care of, choose a garage that doesn't use Magnatec oil and other lower grade 5W-30 oils.

I'm sure there's more to add. I'm sure I'll be put right if I've slipped up. But there ya go!

fuz

we be looking at changing from motul to redline engine oil, just need to decide 10W30
or 15W50

sooby

I use 10W-40 not 10W-30. So I reckon you should choose between 10W-40 and 15W-50.

oilman

iTrader: (9)

Sooby,

Good couple of posts, you have a good understanding of oils and there application, I agree depending on the use of the car, for the Impretza somewhere between the 10w-40 and 15w-50, however the best of both worlds, 10w-50.

Cheers.