5W20 instead of 5W30

[samkblam]

I just changed the oil in my 2002 Legacy. After I had put the oil in, I noticed that the bottle said 5W20, not 5W30 like I thought I had purchased. (Had bought 2 - 5 quart containers). Will this affect the engine, or should I just drain it and start from scratch. Don't really want to if there not any reason to do so.

 

And yes, I should have read the bottle BEFORE putting it in the car, but I didn't this time.

 

Thanks for any input. "and Yes I have done a search"

[NoahDL88]

It should be ok as a winter weight, but if you live in the southern lattitudes, i'd think about changing it.

 

If its colder than a rats rump roast outside right now, you'll be fine.

[cookie]

If you're in Maine in the winter I sure would not worry. Most of the new cars are going to that anyway.

[idosubaru]

no need to worry about it.

[Petersubaru]

I think you will fine in the winter months..the 5/20 oils can by run all year long in any weather for cars that are designed to have tighter bearing clearances together with high pressure oil pumps (not high volume like the subaru has)

[Dr. RX]

I run 20W50 oil in my car year round.

[Setright]

As the others say. Leave it in and consider a change to 5W-30 when summer comes :-)

[Manarius]

I run 20W50 oil in my car year round.

Me too. Keeps the leaks down.

[gbrand]

I would check your owners manual- see at what temp 20W oil can be run and compare to your current/expected temps. My reasoning? the upper number on multi-wieght oil is the number the oil performs at when warm-so whetther is 5W-30 or 10W-30 once your car warms up is like 30W. The 5W-30 gives improved performance in colder weather. Unless it is very cold and you are not going to be using your car for sustained trips the 5W-20W may be too thin for your engine. Again check your owners manual, if 20W oil can be run up to 30 degrees and its 35 or 40 I wouldnt worry too much about it.

 

I was buying oil and filters today and the cases of Castrol 5W-20 have warnings on the boxes to run ONLY in cars designed for 5W-20. I did buy 5 quarts once by mistake, they have black tops like the 10W-40 I was intending to put in my Lagacy-took back and exchanged no problem.

[Dr. RX]

I run 20W50 oil in my car year round.

Me too. Keeps the leaks down.

Not just that but it has better lubricating properties all around, I've learned through the school of hard knocks what using too light weight of an oil can do. I've been building high performance engines for over 35 years, and I won't use anything less.

[Bserk]

Not just that but it has better lubricating properties all around, I've learned through the school of hard knocks what using too light weight of an oil can do. I've been building high performance engines for over 35 years, and I won't use anything less.

 

 

Ok, Im brand new to the board, and brand new to Subarus too, but I am a ASE certified master, with 30 years experiance with Japanese vehicles (99% Nissan) heavy weight oil WILL, in a modern low clearance engine, in cold temps, cause severe damage. Ive seen it. Ive repaired it. Putting 20w50 in a car designed for 5w30 is asking for camshaft seizure in cold weather, Ive seen it first hand. Stick with what is recommended for the car. They didnt pull those recomendations outta the air. Lighter weight in cold weather would likely be ok, better than the opposite

[Manarius]

My ASE certified mechanic with 30+ years experience actually recommended to put 20-50w in so that my car wouldn't leak so much. The weather around here doesn't really get that bad so I figure 20w at cold isn't going to kill the engine.

 

I don't know what you mean by "low clearance" but my car has enough piston-valve clearance that it's not an interference engine - if that has any bearing.

[WoodsWagon]

He means that the oil is thick enough that it doesn't get flowing when the engine is really cold. The bearings have close tolerances, and the camshafts run directly in the head aluminum, so when they don't have oil flowing through them, they eat themselves really quick. With the camshafts running in the aluminum without real bearing material, they can jam and snap the timing belt.

[Petersubaru]

5/20 is recommended for "low clearance" or "smaller clearance" motors...for one example among many , is the crank/bearing space is under .001(.0009) (Honda) ...in the past and many newer hot rod applications along with air-cooled motors like for example VW...the bearing clearance is around .002...also the 5/20 oil pumps are designed to put out more pressure with less volume which is needed for the modern engine..one can easily go on and on with topic, but the main concern here is, (if you are not racing the car) ...is the ability of the oil to get to lubricate the motor as fast as possible apon the "cold" start-up..., even here around the Detroit area, it can at times get very cold...cold enough so that the 20/50 or 15/40 will not come out of the bottle..I do run thicker oil in very hot weather when I visit down south and the temps are 90 or above F...On some of those newer cars you can distinctly here the clatter of the valve train when the weather gets that hot or hotter, AC is on and they are idleing in the mall parking lot...

My ASE certified mechanic with 30+ years experience actually recommended to put 20-50w in so that my car wouldn't leak so much. The weather around here doesn't really get that bad so I figure 20w at cold isn't going to kill the engine.

 

I don't know what you mean by "low clearance" but my car has enough piston-valve clearance that it's not an interference engine - if that has any bearing.

[Dr. RX]

Ok, Im brand new to the board, and brand new to Subarus too, but I am a ASE certified master, with 30 years experiance with Japanese vehicles (99% Nissan) heavy weight oil WILL, in a modern low clearance engine, in cold temps, cause severe damage. Ive seen it. Ive repaired it. Putting 20w50 in a car designed for 5w30 is asking for camshaft seizure in cold weather, Ive seen it first hand. Stick with what is recommended for the car. They didnt pull those recomendations outta the air. Lighter weight in cold weather would likely be ok, better than the opposite

Gee, I have over 120K on my engine (JDM EJ20G) with no ill effects. Yesterday it never got above 26 degrees F, unusually cold for this area. The car started just like it does in 100 degree F weather in the summer. I never got a certificate, but if there were a grand master catagory, I'm sure I would qualify. I've talked to a lot of ASE certified mechanics in my life, and have never been real impressed, so if you were trying to impress me, you didn't. I have proven certified mechanic wrong in the past, and will probably continue in the future. I really doubt that my engine was designed for a 5W30 oil, but if you want to risk engine failure due to oil failure, be my guest.

[WoodsWagon]

As for the ASE system, it really needs improvement. All the books that give test prep are just question and answer, no theory. If the ASE people had a better way of testing whether mech's knew the theory instead of just the correct answer, it would be better. Not dissing you for being a master tech, that's a lot of tests you have to take and keep current with.

 

I was running the competition circuit, and ASE tests are all over the place there.

 

Dr. RX, I would think especially with the turbo that you would want a thinner oil so that it would reach it fast?

[Petersubaru]

26F is still warm enough to move the 20/50 oil, however slowly...Ej20 is still somewhat of an older design and you can still get away with what you are useing...why not ease up on our new member ...I don't think he was trying to impress anyone by stateing that he is an ASE certified mechanic any more then perhaps, and I say only perhaps, and that is, you, trying to impress us by your quote of "35 yrs of building high performance Motors" or "that you are not impressed by many of them"...we could say this about anyone or any group of people, and where does this gets us?...we all end up living in our own ignorance of what we think is the correct way to do things...their are a lot more variables at play here then one may assume..

Gee, I have over 120K on my engine (JDM EJ20G) with no ill effects. Yesterday it never got above 26 degrees F, unusually cold for this area. The car started just like it does in 100 degree F weather in the summer. I never got a certificate, but if there were a grand master catagory, I'm sure I would qualify. I've talked to a lot of ASE certified mechanics in my life, and have never been real impressed, so if you were trying to impress me, you didn't. I have proven certified mechanic wrong in the past, and will probably continue in the future. I really doubt that my engine was designed for a 5W30 oil, but if you want to risk engine failure due to oil failure, be my guest.

[Petersubaru]

We are talking about oil here, aren't we?? Not somebodies creditials... Instead of knocking the ASE certificate, aren't you going to give our new member any credit for his 30yrs of service, working mostly around Japannes cars.. Don't misunderstand me, I am not "dissing" you for being negative about the ASE program...but why equate your ASE views to what our new member has said...after all.. was he wrong in any way to introduce himself that way???

As for the ASE system, it really needs improvement. All the books that give test prep are just question and answer, no theory. If the ASE people had a better way of testing whether mech's knew the theory instead of just the correct answer, it would be better. Not dissing you for being a master tech, that's a lot of tests you have to take and keep current with.

 

I was running the competition circuit, and ASE tests are all over the place there.

 

Dr. RX, I would think especially with the turbo that you would want a thinner oil so that it would reach it fast?

[Bserk]

I wasnt trying to 'impress' anyone, nor was I trying to start a battle of 'knowledge' with any of you. I would also agree that, like any other certification, there are some ASE certified techs that have 'skated' through and aren't worth their salt, so to speak. (But if any of you think the ASE exams are a breeze, I suggest you go take a couple)

I guess I mentioned being ASE certified as a way of introducing myself as someone who has been a tech for many years and has stayed on top of newer technology and takes pride in that fact.

 

Im not going any further with the oil discussion. I have seen OHC Nissan engines sieze cams until the cam has actually snapped in half, destroying the head in the process. Not once, but several times. And its always in extreme cold weather, and always with a thicker grade oil than was specified. This isnt my theory, Ive seen it happen, folks! You live where it doesnt get cold, I guess it wouldnt be an issue. Around here (upstate NY) it is. And thats just a fact. Sorry for being a newbie and apparantly stepping on someones toes, I'll get out of this thread and back to getting some great advice on my Outback!

[Bserk]

ok, I said I was done with this thread but I forgot one thing I was going to add to my last post. The car Im replacing with the Outback is a 94 Sentra...and Im giving up on the poor old girl because the salt has taken a heavy toll on the body/frame, mechanically it runs strong and clean yet. Bought it from the original owner 7 years ago, and have records from day one. 223,000 miles. Engine never touched, valve cover has never been removed! 5W30 ALWAYS, summer and winter. Not a Subie, but similar aluminum heads and clearances, I would bet. Ok, I promise, done with this thread. LOL

[Olnick]

Bserk, I hope you have a good experience with your Outback and will stick with us. Informed input is always appreciated.

 

Aloha.

[Dr. RX]

The weight is the viscousity of the oil, lower number freer flowing. The molecular structure is the same, regardless of weight, it will flow through the same clearance, it just might take a few micro seconds longer for a heavier weight. The engines that I work on and play with are turbo charged, they by nature create more heat then a normal engine, therefore I am more concerned about thermal breakdown in an oil. For the region where I live, the 20W50 give me the best protection. So, a turbo engine would be better off running an oil with a higher weight, avoiding the themal breakdown of a lower weight oil, which would lead to coking (burnt oil buildup) on the turbo bearing surfaces. I'm always reminded of the Bardall commercial were the applied friction to ball bearings spinning in various weights of oil. The bearing in the lighter oil would seize up long before the bearing in the heavier weights and way earlier the Bardall. That to me always showed that lighter weight oils provided less protection, I guess I'll always think that until someone can prove different to me.

[Petersubaru]

I can agree that in your situation the 20/50 oil could be the best...but to give a "blanket statement" that this grade should be used goes against alot of info available..these newer cars that recommend 5/20 or 5/30 or even 0/40 are designed by engineers, in fact a "team" of them, ..I know you are not saying that you are smarter then them??...A few micro seconds longer to lubricate will not make much difference in the beginning for many older designed cars , but will make over time a huge difference for many newer cars that have the TOP piston ring pushed further up the piston ...thus a "low" weight oil coupled with a "high" flash point is needed here......also the "bearing test" you mentioned is akin to checking the quality of your motor oil by "rubbing the oil between your fingers"..it means nothing..it does not apply to high pressure systems..I know you can do the research to find the real truth...

The weight is the viscousity of the oil, lower number freer flowing. The molecular structure is the same, regardless of weight, it will flow through the same clearance, it just might take a few micro seconds longer for a heavier weight. The engines that I work on and play with are turbo charged, they by nature create more heat then a normal engine, therefore I am more concerned about thermal breakdown in an oil. For the region where I live, the 20W50 give me the best protection. So, a turbo engine would be better off running an oil with a higher weight, avoiding the themal breakdown of a lower weight oil, which would lead to coking (burnt oil buildup) on the turbo bearing surfaces. I'm always reminded of the Bardall commercial were the applied friction to ball bearings spinning in various weights of oil. The bearing in the lighter oil would seize up long before the bearing in the heavier weights and way earlier the Bardall. That to me always showed that lighter weight oils provided less protection, I guess I'll always think that until someone can prove different to me.

[Petersubaru]

With all due respect I don't think you meant to hurt anyone

As for the ASE system, it really needs improvement. All the books that give test prep are just question and answer, no theory. If the ASE people had a better way of testing whether mech's knew the theory instead of just the correct answer, it would be better. Not dissing you for being a master tech, that's a lot of tests you have to take and keep current with.

 

I was running the competition circuit, and ASE tests are all over the place there.

 

Dr. RX, I would think especially with the turbo that you would want a thinner oil so that it would reach it fast?

[Dr. RX]

..these newer cars that recommend 5/20 or 5/30 or even 0/40 are designed by engineers, in fact a "team" of them, ..I know you are not saying that you are smarter then them.

Engineers?? I know what those are, I have been one for the past 26 years here at Boeing, I'm a card carriying member of SAE, mostly because the "A" stands for both, automotive and areonautical. Maybe I'll have to delve into the SAE library to see what they have to say. Has anyone here every seen what only 10 psi of pressure can do, it can be very explosive if suddenly released, most engine oil systems operate at 30 psi. Unless an engine is left standing for a long period of time, there is residual oil on the bearing surfaces (the heavier the weight, the more likely to have a residual). At 30 psi the oil system is quickly supplied with fresh oil. What damages an engine most is revving it when it is still cold, this could cause starvation, even at 30 psi. What would a 0W40 oil flow like, water??? I didn't even know that they made such a thing.