Oil grade and type...?

What brand (Motul, Castrol, Mobile1, Amsoil,etc... ) and what type of oil (0w-30, 5w30, etc... ) are you guys using?

I'm in Canada and I'm unsure which type I should run. I get the same climate as you guys in Detroit and New York...

BTW... is there anything special I need to do with the flat 4? I've changed oil on several cars and bikes... but no subi's.

The answer will always be: depends. It depends on your driving habits, how long you warm the car up and mechanical condition of the motor.

My motor is good to go, so I know a quality synthetic will probably go 10k miles or so. I wouldn't go over 5k miles with out a used oil analysis to back it up, though. I use Rotella T6 5W-40, but will be switching to M1 0W-40, since that's what was on sale last. I feel comfortable doing extended drains on these oils. Many others out there are capable of the same with out having to spend as much as you would on Motul 300V, Amsoil SSO, etc.

A good group III synth is the best bang for my buck.

Good info.

How much oil does the 2.5 take btw?

Hey bud,

I'm in Ontario as well and here's a brief explanation on oil.

Regular oil (referred to as dino oil as well) is fine for our cars. I've been using 5w30 on my first motor before the head gaskets went twice on it (first time was preventative maintenance but mechanic screwed it up and only lasted 40,000km, second time I wasn't paying attention to coolant levels so I put in a JDM engine)

With the JDM engine, it was super clean so I started using 5w30 Valvoline full synthetic because its cheap at Walmart.

Dino oil, is dino oil.. regardless of make.. Synthetic is where it gets complicated because different makers add different additives. Oil filters are more important.. stay away from Fram filters as they use a cardboard cartridge filter inside-- horrible!

Read the link that rmb2485 posted.. good info. I stick with PowerFlo (Purolator sister brand) that I get for $3.

Now the difference between Synthetic and Regular oil. Imagine a gymnasium floor and all different size balls, like soccer balls, golf balls, volley balls, scattered all over.. these balls represent the molecules that make up the oil.. all different sizes and volumes right? Doesn't work as well in heat dissipation if they were all the same size.

Synthetic oil is engineered so that all the molecules are the size of golf balls.. a more uniform surface which results in better heat dissipation and since the molecules are smaller, the oil can lubricate better and there's a lot of rumours that people say switching to Synthetic oil causes seals to leak-- this is untrue. Because the molecules are smaller, it reveals leaks SOONER. The leak was always there.. you're just more aware of it now.

If there's a lot of km on your car.. I wouldn't switch to Synthetic.. stick to regular, just monitor your oil changes and use a good filter and your engine will love you

Some good info, but you're over-simplying it. All mineral oils are not the same, and vary in base stocks and add packs just the same as synthetics do. There are Group II and Group II+ mineral oils, Group III "synthetics", and true Group IV/V synthetic base stocks. An oil company may choose to blend a mostly Group II/II+ base stock for it's cheaper, value-based formula, a mixture of Group II+/III for it's synth blends and a mixture of Group III (maybe with some Group IV PAO added in to achieve certain characteristics) for it's "full" synthetic formula. The only true fully synthetic oils are those that are Group IV/V oilssuch as Amsoil SSO, Motul 300V, Redline, Royal Purple, etc.

As far as the molecular size analology - not quite. It's more like molecular chains of differing lengths and characterisics. A synthetic will require fewer viscosity index improvers - the add that allows for a lighter weight oil to maintain a higher viscosity at operating temps - to maintain the same cold flow properties and high operating viscosity because the chain lengths and properties are designed to suit. This also helps with thermal break down and degradation in the form of oxidation, etc.

In all, an oil's quality is based on how stout it's base stock is, how many adds are used to make up for any base stock deficiencies, and the quality of the additives. The add pack only makes up ~20% of the oil, so if a higher percentage goes toward viscosity index improvers, less will be for cleaning (and dispersancy), anti-wear, etc.

Some good info, but you're over-simplying it. All mineral oils are not the same, and vary in base stocks and add packs just the same as synthetics do. There are Group II and Group II+ mineral oils, Group III "synthetics", and true Group IV/V synthetic base stocks. An oil company may choose to blend a mostly Group II/II+ base stock for it's cheaper, value-based formula, a mixture of Group II+/III for it's synth blends and a mixture of Group III (maybe with some Group IV PAO added in to achieve certain characteristics) for it's "full" synthetic formula.

 

As far as the molecular size analology - not quite. It's more like molecular chains of differing lengths and characterisics. A synthetic will require fewer viscosity index improvers - the add that allows for a lighter weight oil to maintain a higher viscosity at operating temps - to maintain the same cold flow properties and high operating viscosity because the chain lengths and properties are designed to suit. This also helps with thermal break down and degradation in the form of oxidation, etc.

 

In all, an oil's quality is based on how stout it's base stock is, how many adds are used to make up for any base stock deficiencies, and the quality of the additives. The add pack only makes up ~20% of the oil, so if a higher percentage goes toward viscosity index improvers, less will be for cleaning (and dispersancy), anti-wear, etc.

Oh jeez.. and I thought I knew what I was talking about.. lol.

We can continue going deeper and I could take some chemistry courses and dissect oil to the very foundation of it but its' irrelevant in everyday use. I appreciate your further analysis, but simplifying is something that everyone can relate to and understand.

I love photography and I can go on about how camera's mimic the eye because it totally fascinates me but for the everyday person to understand (and not a lot of people know what the difference between Synthetic oil and regular oil is), the analogy is accurate and simple. It may not be 100% fact, but it helps people to understand the basic difference between the two properties.

What you said.. even has me scratching my head and doing this

I still love you though.. not trying to disregard your post but most people.. won't get it.

Well, my previous boss said something I'll always remember: "Unless you can explain the most complicated thing you know to some Idaho farm boy and have him understand every word, you don't know what you're talking about." I'm glad you still love me even if I don't know what I'm talking about, apparently haha!

To qualify my last post, I'll say that all oils are not created equal, especially if you're mentally or physically unable to utilize a better oil to its fullest potential. For the same car, if you take a cheap ($2/qt) mineral oil capable of lasting 4,000 miles and an expensive ($10/qt) synthetic oil capable of lasting 20,000 miles, but refuse to run either oil for greater than 3,000 miles, either because you mentally can't see going long or have mechanical issues like coolant leaking into the oil that preclude going longer, there will be no difference except a lighter wallet with the latter oil. Granted, the synthetic may hold up better and keep damage caused by a contamination issue at bay more efficiently, but that's beside the point.

If you would like to extend your oil change intervals, clean up a neglected engine or have a case where a stouter oil is required, then a better oil (not necessarily synthetic) may be for you. If you want to go all out and extend your oil changes WAY out, and are ok doing so with the backing of used oil analyses, then synthetics may be for you. If you putter along on the highway, have a perfectly working motor and refuse to go past 3,000 miles, then the cheapest API SM-rated oil may be for you.

With all that being said, peace of mind is worth something, and the cost difference for a much more expensive oil, while still changing every 3,000 miles, pays that difference and then some (for some people.)

I'm glad you still love me even if I don't know what I'm talking about, apparently haha!

My bad, I wasn't trying to say you don't know what you're talking about-- I'm sure you know a lot more about oil than I do, but what I meant to say was that most people won't understand the depth of your post because most people just don't care to know that much.

And yes, I still love you.. sorta.

And thanks for the simplified version.. makes much more sense

And I'm pointing over here: http://legacygt.com/forums/showthread.php?p=1664482#post1664482

And now we just wait for rao to tune in!

Subaru filter

Usually Wal-mart brand full synthetic 5w30.

I don't care who actually makes it or what is put in it...cheap clean oil is better then dirty "good" oil.

how do you determine clean vs dirty oil?

Well, my oil at 3000-4000 miles will be cleaner then it will be at 6000-7500 miles which is what some people like to stretch their changes to because they have "good" oil. I know Subaru says 7500 mile intervals under normal driving conditions for an NA engine but, whatever.

The only reason I use synthetic in my 97 GT is because in the winter when I leave for work early in the morning when the temp is single digits, to me, the car doesn't sound so angry when it turns over as it does with dino oil.

A good oil is just as "clean" at 6k as it is at 3k. Going by your logic why not change every 1k? Oil at 1k should be "cleaner" than at 3k, right? You seem skeptical about NA Subies going 7500 miles on an oil change, but that's just about what I do in my STI. I plan to go to 10k in the LGT if UOA says I can. We gotta stop being scurred when it comes to modern oils...

All joking aside, an oil will have detergents and dispersants to maintain a clean engine or clean up a neglected one, and an alkylinity reserve for neutralizing any acids formed due to moisture and blowby.

the oil is "clean" as long as you don't overwhelm the oil with too-long OCI's or have the filter in bypass due to it reaching it's capacity.

Expensive oil or cheap oil, no matter what I usually change my oils at around 5000-6000 kilometres, so 3000-4000 miles. As for oil filters, I usually buy whats on sale, haha I guess I'll stop cheaping out on it.

I changed my oil last week, I used Mobile1 Synthetic 5w30 oil because it was very cheap and on sale and a Fram oil filter. Since my car is my DD, I'll be changing oil quick! On my next oil change I'll pop in a more expensive filter and 10w30 oil because my car burns oil fast and 10w30 is thicker than 5w30 (i think) so its better for hot summer weather...

My theory can be totally wrong, but its what I've been doing for all my subie life and my cars at almost 190k kilometres and 0 HG problems.

Well, I'll add my $.02 here. We have a 99 Legacy 30th Anniversary L Sedan, 2.2l 5spd. Purchased new in the Poconos w/ 79 miles on it & I've used Mobil1 Synthetic since the second oil change after break-in. (Ran the same oil in my 93 Ranger 3.0L 4x4 pickup from 74K thru 217K miles.) Since the Legacy wasn't garaged much, in cold of winter I ran 1.5Q 0W-30 & 3Q 5-W-30. (REALLY cut down on valve rattle at cold startup!) Spring thru Fall ran 5W-30. Once I hit 150K miles, I ran the same as above in Fall & Spring, mixed 1.5Q 10W-30 with 3Q 5W-30 in Summer, especially for trips south to the Carolinas & Virginia. Did 3000 mile intervals UNTIL Mobil1 developed their 15K mile Extended Mileage oil. I now run Only the 15K extended mileage oils, 4.5Q 5W-30 winter, spring & fall, & mix 1.5Q 10w-30 3Q 5W-30 for Summer. Changed to a 5000 mile filter interval and a 10000 mile oil interval. Just drive too many miles (35-50K per year combined) to justify having to change oil SO often on 3 cars and stay on top of the correct intervals. Now it hits on the 5K & 10K. We now have 223K miles on it and still love the way it works (got 36 mpg Hwy with General Altimax snows back in January.) I can't complain about it, and will stick with it. (Recently switched new Highlander to the same cycle.)

My dad uses AMSOIL on his diesel & hemi Ram, but I see no need to switch now.

Filters: WIX, Purolator or Mobil1 (K&N in a pinch), depending on if I can get them in stock when I need them.

Kinda rambled, but hope my experience may help.

TRIED to run Mobil1 10w-30 in my 81 Buick 3.8L @ 110K miles- THAT car did NOT like the synthetic switch-too much leak by on the valve guides- switched to any 10W-30 semi-synthetic & much happier.

Expensive oil or cheap oil, no matter what I usually change my oils at around 5000-6000 kilometres, so 3000-4000 miles. As for oil filters, I usually buy whats on sale, haha I guess I'll stop cheaping out on it.

 

I changed my oil last week, I used Mobile1 Synthetic 5w30 oil because it was very cheap and on sale and a Fram oil filter. Since my car is my DD, I'll be changing oil quick! On my next oil change I'll pop in a more expensive filter and 10w30 oil because my car burns oil fast and 10w30 is thicker than 5w30 (i think) so its better for hot summer weather...

 

My theory can be totally wrong, but its what I've been doing for all my subie life and my cars at almost 190k kilometres and 0 HG problems.

Same viscosity at operating temp.