Age old oil question

[92_rugby_subie]

I have run Chevron 10W30 in Ned since I got him (before I got him I did an oil change with it too) with no issues. When the head gasket blew and began leaking oil externally I switched to Valvoline 10W40 Synthetic blend and it seemed to slow the amount that I leaked but I did notice my oil pressure was a little higher. However that was summertime and with fall/winter approaching I need to do another oil change and I get a nice discount on oil and filters at my dealership.

 

They have a Mobil1 synthetic blend but it comes in 5W30 only... I have seen people run 5W30 with no issues but in terms of behavior, what might I see? More oil consumption? Better gas mileage? Lower/higher pressure?

Edited September 18, 2013 by 92_rugby_subie

[bratman18]

I have run 10w40 in all my EA cars year round. Always have, and for the exact reason you said, it helps reduce leaks. The EA82's leak oil, pretty much no matter what you do lol. It gets cold here in the winter, and I've never had issues running the thicker stuff, even well below freezing. But that's just my experience.

[Carl B.]

If you have a worn out old motor that leaks oil just run the cheapest stuff in a weight that matches the climate.  Thats what I do.  

[Loyale 2.7 Turbo]

If you have a worn out old motor that leaks oil just run the cheapest stuff in a weight that matches the climate.  Thats what I do.  

 

Sorry to Disagree, but a Cheapo motor Oil will make things to worn even Worse and faster.

 

This is an Excerpt of my Motor Oils' Writeup:

 

 

 

Remember: The viscosity of a fluid describes its resistance to flow. “Thick” fluids such as honey have a high viscosity and flow very slowly. “Thin” fluids such as water have a low viscosity and flow much faster under the same conditions.

 

Viscosity depends strongly on temperature and is a major factor in lubricating oils for engines. The specification “10W~30” (“W” means “winter”) in a motor oil means the viscosity of the oil at 0º C (32º F) is no more than 3.1 poise while the viscosity at 100º C (212º F) is no less than 0.1 poise.

 

in other words: A 10W~30 Oil will be thin as "10" at Ambient Temperatures, and will become thicker as much as "30" when the engine reaches its normal operating temps. So those oils with a "W" on their SAE Grade, are "Multigrade" Oils, (W for Winter times) which means that the Oil will be as Thin as the First Number on their SAE Grade when the Engine is Cool (to aid a Faster and proper oil Flow when you First start the cool Engine); and will become as Thick as the Second Number on their SAE Grade when the engine Reaches its Normal operating Temperatures, (in order to have enough protective oil film between moving metal parts).

 

 

You must choose between the Oil Viscosity and Additive Pack that best fit your Engine's age, your Kind of Driving and the Climate of the World's area where you Live; so the Smart choice is always to choose the better motor oil to Achieve the Balance between flow and usage, because a very thin motor oil will help you to save Gas (Energy Conserving) but will worn faster the engine's internals than a Thicker motor oil, but if you go too thick, the low flow pressure could worn things faster too.

 

You can Reach the Full Writeup, Here:

 

~► http://www.ultimatesubaru.org/forum/topic/126284-how-to-determine-which-is-the-best-motor-oil-for-your-car/

 

Kind Regards.

Edited September 19, 2013 by Loyale 2.7 Turbo

[AdventureSubaru]

Been running Supertech (Walmart) 10W40 in my Subarus for years with no problems. I've seen little difference in oil quality between brands. Only that the expensive stuff can last longer between changes. But Supertech (Or about anything else) every 3000 miles religiously has been flawless. I have never had a subaru engine go bad under my care and currently driving odometers of 332,000 and 275,000 with that care. Keeping them topped off religiously is the other half of the battle, but is also a common part of the Subaru religion.

 

Probably stick with what's working. Subarus don't seem to mind the thick stuff.

[Dee2]

There's not a significant difference between 5w-30 and 10w-30.  I doubt you will notice anything different.

[nobangmycar]

_{I agree.  The API ratings are also important.  A 10w40 will be just fine.  As long as the API rating (SM/CF for example) matches the standard required for your engine, you will be fine.  Low Viscosity doesn't mean more engine wear at all, it depends on the quality of the oil, and the best viscosity for your temperatures and engine.  You normally find that engines with tighter clearances in bearing shells etc run a lower viscosity oil.  I have an EA82 with 281,000kms on the clock and I run a 20w50 with no problem, although a 15w40 or slightly less would be better.  Hope this helps.  I sell oil for a living, and am happy to help with your questions.}

[tweety]

10W-40 synthetic blend.  Blend is good.

[MilesFox]

I always run 10w30, or at least any flavor of 30 wt. Midwest 4 season climate -10 deg-95 deg seasonal temps

[l75eya]

Doesn't oil get thinner the hotter it is? Like the honey analogy, honey had a high cisco viscosity, but only when is cold. Heat honey up and it turns into a low viscosity liquid. Same thing with syrup. So how does oil work any differently?

[naru]

There's not a significant difference between 5w-30 and 10w-30.  I doubt you will notice anything different.

 

My 84 owners manual disagrees.I quote:

 

CAUTION

SAE 5W-30 is not recommended for Turbo vechiles and sustained high speed driving on all vehicles.

 

It goes on to say that 5-30 is OK as long as the temperature does not exceed -25 C or -13 F.

[92_rugby_subie]

Well snaps... thanks for the responses guys!

 

I guess we will see what the 10W40 does to the car in the winter time... I have access to it just not at a discount... always penny pinching when you have an old scoob that's for sure!

[nobangmycar]

When oil is heated and put under pressure the viscosity increases.  I know this sounds mad, but it's true.  That's why the multigrade engine oil viscosity ratings are higher on the second number.  There is very little difference between 5w30 and 10w30 oils of the same API rating, Dee2 is right.  Normally more modern cars with hydraulic lifters (not the old OHV stuff I muck with) need an oil with a lower viscosity when cold so a 5w## or 10w## is good.  Semi synthetic blend also a good idea as the quality of the oil additives are much better.  Remember 'synthetic' is a broad term, all oil comes out of the ground.  Synthetic oil is just chemically stuffed with to take out bad stuff and add in good stuff, instead of just refining and adding additives.

[92_rugby_subie]

So what youre saying is that going from a 10W40 to a 5W30 isn't a big difference as long as they are of the same quality?

[Loyale 2.7 Turbo]

There should be a Difference: 5W~30 should be Easier on Cold Starting and acceleration (Energy Conserving Oil) but it will develop more engine internal's wear on the Long Run, than using the Thicker 10W~40 for sure.

 

Kind Regards.

Edited September 21, 2013 by Loyale 2.7 Turbo

[Flowmastered87GL]

I will throw in what I used on my 87 GL... I ran 20W50 under advice from my former mechanic (before Richie) to combat the tick of death.  It worked but I am not sure if It contributed to the death of my engine or not.  I bought the car with around 217K, swapped the engine shortly after that (JDM import engine) and got about 100K out of it before it blew up (when cold)  It kept my oil pressure up for sure.... but I doubt it flowed very well when cold.  Not sure if I would recommend it or not.  Maybe the oil killed it, maybe the years of rallycrossing and pizza delivery killed it.  It died at around 321K though.

Edited September 22, 2013 by Flowmastered87GL

[Loyale 2.7 Turbo]

Well...

 

20W~50 is Good for Hot Climates,

 

but not good at Cold Starting on Cold Climates

 

on which you shall switch to 10W~30.

 

Kind Regards.

[nobangmycar]

The 5W30 is 'thinner' or has a lower viscosity than the 10W40.  Neither will cause more wear, one is just a little thinner.  I would run a 15W40 or a 10W40 and you'll be fine.  If you go too thin, you'll burn a bit and get a bit tappy when hot, if it's too thick it'll start with a tack, tack, tack, tack, tack, tick, tick, t, t, t, brrrrrrrrr that we are all familiar with.

[Loyale 2.7 Turbo]

There's a Reason Why Subaru shows Different Oil Viscosities to be Used on EA engines, (As you can see on the Owner's Manual) depending on Climates as I Wrote above; other car makers has stated the same. 

 

 

These are Scans of my 1983 Subaru Owner's Manual:

 

 

 

 

Very Kindly I suggest you to See the Engine Oils' Writeup I posted, following the Link found on Post Nº 4 of this thread, then scroll down there; you'll reach a Downloadable .pdf document file that shows an Australian Test done to explain how a thin or thick film of oil behaves on engine's internals. Worth Downloading (is a small file with Photos) and Reading. (Has Few Pages)

 

Kind Regards.

Edited September 22, 2013 by Loyale 2.7 Turbo

[nobangmycar]

Time to give up I feel.

[idosubaru]

oil discussions are pointless.  follow the owners manual, there's no need to go beyond that. brand and type don't matter, just follow the owners manual.  for every person that makes one claim there's someone else doing the opposite and getting 300,000 miles - it's obviously pointless.  subaru's (2000+ turbo's notwithstanding) easily make 300,000 miles regardless of conventional, synthetic, etc.

 

people like to talk about oil because everyone is right and no one can resist not being right about something.  whatever you do is right because everything works fine...follow the owners manual. conventional, synthetic...just don't be dumb and you're golden.

[Loyale 2.7 Turbo]

I Completely Agree with grossgary.

 

Kind Regards.

[nobangmycar]

Me too. Fair call Gary!

[idosubaru]

it's good to ask - there are instances where it's a dire necessity like newer Subaru EJ turbo engines that are problematic regarding oil supply.  and if you're towing huge loads often, racing, living in sub-saharan africa, or the arctic circle, or you want to make 1,000,000 miles - good to rethink that/ask about oil.

 

but for average daily driver Subarus at least the discussion about ends there - follow the owners manual.

 

as much as i'd like to herald myself as the subaru-shiznit-of oil changing engine longevity and the miles i get out of them, it's got nothing to do with my random selection of on-sale oil and filters, i simply know how to read...the owners manual.

 

for the person that touts a brand or method that gets them 300,000 miles and a clean engine - there's 100 guys buying whatever is on sale and getting the same results....they just don't talk about it.  luckily - this forum has more of the "100" guys in it....some forums it's the other way 'round.

[MR_Loyale]

I think the biggest point is to religiously change the oil. I do it every 3000 miles or three months and will until the day I die. All the consumer reporting places that tell you to wait longer are full of it. Oil is cheap, engines ar expensive. You can take the oil can from my cold dead fingers.

 

Now about that slick 50...