Is 5w40 too thin
13 June 2007, 11:46 PM
#31
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oil
10w 40w is the right oil to use.
10w 60w or 15w 50w oils are to thick you will kill the turbo unit from starvation of oil because inside the turbo unit you have small holes in the bushing. You should prep the engine first before starting the car up otherwise your big ends wont last long ok.
Castrol TXT 10w-30 full syntethic oil, which is 100% percent pure synthetic
Motul 300v, Shell helix 5/10w-40 semi synthetic latest API/SAE spec (e.g. an API 'SL' grade). ENEOS 10w-40 semi synthetic try this oil Japarts 08450664422
Change your oil every 3500 miles would be the best.
Like I do chaps. Only prep the engine after changing the engine oil I forgot that bit sorry
10w 60w or 15w 50w oils are to thick you will kill the turbo unit from starvation of oil because inside the turbo unit you have small holes in the bushing. You should prep the engine first before starting the car up otherwise your big ends wont last long ok.
Castrol TXT 10w-30 full syntethic oil, which is 100% percent pure synthetic
Motul 300v, Shell helix 5/10w-40 semi synthetic latest API/SAE spec (e.g. an API 'SL' grade). ENEOS 10w-40 semi synthetic try this oil Japarts 08450664422
Change your oil every 3500 miles would be the best.
Like I do chaps. Only prep the engine after changing the engine oil I forgot that bit sorry
Last edited by magicseven; 16 June 2007 at 07:02 PM.
14 June 2007, 01:01 AM
#32
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I've used 5w40 in every Impreza I've owned (7+) in the last 8 years. All have been run hard on the road, and have spent 30%+ of their life on track.
I have never had a problem with piston slap, and I have never had acar let go (other than an STi5 TypeR I bought and got less than 10 miles in).
If I can offer any real advice though, it's to choose who you listen to very carefully. There are far too many on scoobynet who either talk through their **** or simply repeat what they've been told without taking time to digest or understand it.
I am, however, quite prepared to have an expert such as David @ API (or any of the others that really know what they're talking about, and there are only a handful these days) put me in my place.
I shall now step down from my soap box
I have never had a problem with piston slap, and I have never had acar let go (other than an STi5 TypeR I bought and got less than 10 miles in).
If I can offer any real advice though, it's to choose who you listen to very carefully. There are far too many on scoobynet who either talk through their **** or simply repeat what they've been told without taking time to digest or understand it.
I am, however, quite prepared to have an expert such as David @ API (or any of the others that really know what they're talking about, and there are only a handful these days) put me in my place.
I shall now step down from my soap box
14 June 2007, 01:32 AM
#33
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Seeing that both 5w-40 and 10w40 have the same HOT viscosity, it won't be too thin; at 100 degrees they are both more or less the same thickness.
Of course anyone who doesn't understand the viscosity system and how the designation system works will tell you differently. There is far more to oil than viscosity.
The only difference between 10w40 and 5w40 is one will tend be synthetic, and the other usually will be semi-synthetic, and thats what allows the synthetic (hydrocracked usually) to have a lower cold temp viscosity (i.e 5w), which makes it better, not worse.
An exception is if you boil your oil, (so to speak). And put it this way, if you do it with a 5w-40 synthetic...you'll have the same problem, if not worse with a semi-synthetic 10w-40 oil, as the latter will not tolerate sustained high temps and shear as well as a synthetic.
And thus this is why the oil will need changing more regularly if the car is used hard or putting out more BHP (more power=more heat)....Classic imprezas had a 6month/7.5K miles service intevals to start with for a standard car driven NORMALLY (And that means within the legal speed assigned to UK roads), this is based on the use of semi-synthetic oils, and the expected lifespan it can endure before it deteriorates.
To compensate for a car driven that is driven hard, one has a choice; more frequent oil changes, or use of a better oil. Better meaning one that withstand high temperatures and shear stress. A thicker oil (10w50 or 15w50)will compensate, as will an Ester based synthetic oil which uses more stable and durable basestock, so will stay in it rated vicousity band for longer, negating the need for a thicker oil.
Its not rocket science, but some people think it is
Of course anyone who doesn't understand the viscosity system and how the designation system works will tell you differently. There is far more to oil than viscosity.
The only difference between 10w40 and 5w40 is one will tend be synthetic, and the other usually will be semi-synthetic, and thats what allows the synthetic (hydrocracked usually) to have a lower cold temp viscosity (i.e 5w), which makes it better, not worse.
An exception is if you boil your oil, (so to speak). And put it this way, if you do it with a 5w-40 synthetic...you'll have the same problem, if not worse with a semi-synthetic 10w-40 oil, as the latter will not tolerate sustained high temps and shear as well as a synthetic.
And thus this is why the oil will need changing more regularly if the car is used hard or putting out more BHP (more power=more heat)....Classic imprezas had a 6month/7.5K miles service intevals to start with for a standard car driven NORMALLY (And that means within the legal speed assigned to UK roads), this is based on the use of semi-synthetic oils, and the expected lifespan it can endure before it deteriorates.
To compensate for a car driven that is driven hard, one has a choice; more frequent oil changes, or use of a better oil. Better meaning one that withstand high temperatures and shear stress. A thicker oil (10w50 or 15w50)will compensate, as will an Ester based synthetic oil which uses more stable and durable basestock, so will stay in it rated vicousity band for longer, negating the need for a thicker oil.
Its not rocket science, but some people think it is
14 June 2007, 08:25 AM
#34
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10w 40w is the right oil to use.
10w 60w or 15w 50w oils are to thick you will kill the turbo unit from starvation of oil because inside the turbo unit you have small holes in the bushing. You should prep the engine first before starting the car up otherwise your big ends wont last long ok.
Castrol TXT 10w-30 full syntethic oil, which is 100% percent pure synthetic
Motul 300v, Shell helix 5/10w-40 semi synthetic latest API/SAE spec (e.g. an API 'SL' grade). ENEOS 10w-40 semi synthetic try this oil Japarts 08450664422
Change your oil every 3500 miles would be the best.
Like I do chaps
10w 60w or 15w 50w oils are to thick you will kill the turbo unit from starvation of oil because inside the turbo unit you have small holes in the bushing. You should prep the engine first before starting the car up otherwise your big ends wont last long ok.
Castrol TXT 10w-30 full syntethic oil, which is 100% percent pure synthetic
Motul 300v, Shell helix 5/10w-40 semi synthetic latest API/SAE spec (e.g. an API 'SL' grade). ENEOS 10w-40 semi synthetic try this oil Japarts 08450664422
Change your oil every 3500 miles would be the best.
Like I do chaps
And you can't be serious about 'preping the engine' every time you want to start it?
14 June 2007, 08:35 AM
#35
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It beggars belief why this Oil question comes up again and again.
The answer is in the Subaru Handbook which comes with every car.
If the car is modded or used outside the 'normal' limits then - to be brutally honest - you should know a basic like 'which oil should I use' or you shouldn't be in possession of such a vehicle.
Main Dealers do not **** about pre-filling filters and disconnecting sensors after an oil change ....... you shouldn't worry either (I do, however, pre-fill my Oil Filter ... I know it's not needed and is **** but I do it anyway).
A lot of bollox is spoken on these pages about Oil - a 10W-40 Semi meeting the Subaru Spec is absolutely fine for the normal Subaru!! Whether it costs £15 or £60 your engine will know no difference!
The answer is in the Subaru Handbook which comes with every car.
If the car is modded or used outside the 'normal' limits then - to be brutally honest - you should know a basic like 'which oil should I use' or you shouldn't be in possession of such a vehicle.
Main Dealers do not **** about pre-filling filters and disconnecting sensors after an oil change ....... you shouldn't worry either (I do, however, pre-fill my Oil Filter ... I know it's not needed and is **** but I do it anyway).
A lot of bollox is spoken on these pages about Oil - a 10W-40 Semi meeting the Subaru Spec is absolutely fine for the normal Subaru!! Whether it costs £15 or £60 your engine will know no difference!
16 June 2007, 06:32 PM
#39
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no only prep the engine after changing the engine oil. When you start to run some Series POWER Chrispurvis100 you will find out about oil starvation matey
Last edited by magicseven; 16 June 2007 at 06:37 PM.
16 June 2007, 06:56 PM
#40
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Last edited by magicseven; 17 June 2007 at 09:17 PM.
16 June 2007, 06:57 PM
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