Oil FAQ: Read if you want more information on oil, oil filters, and oil changes!

[Unabomber]

Oil FAQ

What is the best oil? Simply put, there is no best oil. While I stand by my premise that there is no best oil, I will offer recommendations as to what I have found are the "best oils":

Synthetic: Mobil Delvac 1 or Lubrication Engineers 8530 MONOLEC
Regular: Pennzoil or Havoline
Synthetic/Regular Blend: Motorcraft

What type and amount of oil should I use? Refer to and use what your vehicle owner's manual requires for your vehicle and engine type. Special Note to Forester and STi owners: The amount listed in your owner's manual is incorrect. The corrected amount can be found via this link. For turbo model Subarus, there has been an important change, please visit this link for details on the new oil types, as well as important changes to oil change intervals that will trump the advice in owner's manual. For 2011+ turbocharged Subarus + NA Forester, synthetic oil is now REQUIRED to be used (more info).

Does my new Subaru come filled with a special "break in" oil? No. All Subaru engines are factory filled with: Nisseki-Mitsubishi M1K 5w-30 with no special additives. Note: the manufacturer changes from time to time, but they always use 5w-30 mineral based (non synthetic) oil. All new Subaru 2011+ turbo engines and 2011+ Foresters are factory filled with SOA 5w-30 synthetic oil made by Idemitsu Lubricants America Corporation.

How do I check my oil? The oil should be checked warm. This means your engine has been run enough for the coolant temp level to be normal. The best spot for checking is during fill ups as most gas stations have 100% flat surfaces at the pumps. The distance between the holes equals 1 quart. If the oil level is in the middle of the holes, it is properly filled. The bottom hole equates to 1/2 quart low and the top hole equates to 1/2 quart too full. Keep in mind that you should check your oil several times in one session as occasionally, it will give false readings as the dipstick is a crude instrument for measuring.

A note about oil levels though. As long as you are between the two holes, you are 100% fine. If you are at the bottom hole, add 1/2 quart at your earliest convenience. If you are at the top hole, you can run your car as normal without removing any oil. Once you are outside the lower and upper oil limits, you should become concerned about an immediate removal or addition of oil.

Since I live in Alaska, should my oil weight be different than someone who lives in Phoenix? This is a hotly debated topic since motor oil weights are "designed" for different temperature ratings. There are many oil weight charts that show which weights are "best" for which temperature extremes. The American Petroleum Institute, Society of Automotive Engineers, and nearly every oil manufacturer state plainly that you should use what your owner's manual recommends. API Motor Oil Guide (.pdf document). If your vehicle is used in desert areas with very high temperatures or for other heavy duty applications, the following viscosity oils may be used: API classification: SL or SJ. ILSAC classification: GF-3. SAE Viscosity No.: 30, 40, 10W-50, 20W-40, 20W-50.

How often should I change my oil? Refer to and use the maintenance schedule in your owner's manual. For turbo model Subarus, there has been an important change, please visit this link for details on the new change frequencies that will trump the advice in the subaru.com instructions linked above.

Should I do my first oil change early on my brand new car? Not recommended and not needed. Many users will "violate" their oil change schedule by doing their first change early. The theory is to remove any break in contaminates during the first few hundred or up to 1000 miles. In practice though, contaminates are collected in the oil filter. While not necessary, this is one oil change that many feel much better about doing than not.

Why do some companies or even my dealer always recommend an oil change every 3000 miles? The more often you change it, the more money they make.

What do independent companies say with regard to oil changes and frequency? Consumer Reports tested 20 motor oils over 22 months on New York City Taxicabs. Their results basically stated to use the oil recommend and the change frequency schedule stated in your owner's manual. The full article may be read via this link.

Is it bad to change my oil more often than the owner's manual states? Changing your oil more frequently than required has no negative aspects other than increased maintenance costs.

My car has a turbo, isn't synthetic the best bet for turbos? Subaru turbos are cooled by oil and coolant using a convection system, with coolant handling the cooling needs once the engine is turned off. Older turbo cooling technology relied solely upon oil cooling and synthetics are probably a better bet for those systems.

If I want to use synthetic, when should I switch? This is a hotly debated topic and you will find many convincing arguments for waiting a certain amount of miles or oil change cycles. There is no evidence that one particular time is best, so switch to synthetic when you feel is best, be it at 10,000 miles or 10 miles.

My car has XX,000 miles on it, can I switch over to synthetic? Yes. Some recommend an engine oil flush prior to the synthetic conversion. An engine flush is usually a very thin oil designed to remove old oil deposits. There are many convincing arguments as to whether this step is required or not. Arguably the best engine flush treatment is Auto-RX.

Can I switch from regular oil to synthetic and back and forth willy nilly? Yes. No real reason to, but you can do so if you wish.

What types of motor oil are available? There are three main types:
1. Plain oil AKA mineral based oil or dino oil
2. Synthetic
3. Blends which are a combination of synthetic and dino oil

Are there different types of synthetic? Yes.
1. Group III is a highly processed dino oil.
2. Group IV is PAO (polyalphaolefin) based oil.
3. Group V is an ester, polyolester, or everything else not classified in the other groups.

Which companies make quality synthetic motor oils? Some of the more popular manufacturers are:

Red Line
Mobil 1
Motul
Neo
Royal Purple
Amsoil
Lubrication Engineers

How do I know what my synthetic or dino oil actually contains? Most motor oil manufacturers have .pdf or html documents listed on their website that contain physical property data and/or MSDS sheets that go over which basestock group it is, additives, and other information about their oils.

Are synthetic blends a good compromise? Yes and no. With commercially available synthetic blends, you have no idea of what the synthetic to dino oil ratio is. One would assume it would be 50/50, but it could just as easily be 10/90. A better and more economical compromise would be to mix your own using a quality dino oil with a quality synthetic. This is an undertaking for more advanced users and should be performed only after careful research.

What about extended oil changes when using synthetics? Extended drain intervals are possible with synthetic oil and some regular oils. To find out at what interval your oil needs to be changed, you need to institute a system of oil analysis. Blackstone Labs provides analysis services to help you determine your oil change interval. Keep in mind that even with synthetics, the oil change interval still should be the same according to the owner's manual. Use of extended oil changes through oil analysis should only be attempted by advanced users, and only after careful research.

What is the best oil filter? Simply put, there is no best oil filter. Popular opinion says the "top filters" are the OEM filter, Mobile 1 filter, and Purolator One filter. For further oil filter information, examine these oil filter studies:

a. Russ Knize oil filter study
b. Oil filter study
c. NTPOG Oil Filter Review
d. Engine Oil Filter Study
e. Armand's Subaru Oil Filter Study
f. LesabreT.com's Oil filter write up
g. Paranoid Fabrication's oil filter expose

These studies, though not all Subaru specific, outline the general characteristics of oil filters for comparison purposes. Visit your dealer or favorite online retailer for the current Subaru OEM filter. Subaru likes to change part numbers every other week, so rest assured your dealer will have the latest version. If you are using an "older" filter, you car is fine and you can continue to use up your old supply until your dealer gets the latest version.

How do I change my own oil? All the necessary tools, tips, tricks, and other oil change related advice can be found by visiting these links:

Scoobymods.com instructions for the Forester.
Scoobymods.com instructions for the Impreza
Scoobymods.com instructions for the Fumoto Oil Drain Valve
A complete n00b's guide to changing the oil in your WRX

Even if your car model is not listed above, these links provide excellent applicable advice for your particular model.

What about engine oil additives such as Slick 50, Duralube, STP, Prolong, etc.? You would be hard pressed to find an engine oil additive manufacturer that hasn't been successfully sued by the Federal Trade Commission. There are also several motorsports and consumer magazines that speak against adding anything to your oil. Here are some articles about engine oil additives:

Article by Chris Longhurst
Consumer Reports article
Snake Oil!
SOA's position on additives

What about magnetic drain plugs or magnets for your oil filter? An oil filter has the ability to filter objects smaller than the human eye can see. If you use a magnetic drain plug, magnets on the bottom of your oil pan, or magnetic devices on your oil filter, they do work, however, they are only holding particles that would normally end up in your oil filter anyway. There is no harm in these devices, however they provide no additional protection. Don't believe this? Read this link for evidence.

Any other good articles on oil? These articles may provide additional helpful information:

Engine Oil Bible
The Oil FAQ
Motor Oil Myths
Motor Oil Bible (zipped .pdf file)
Motor Oil by AE Haas

Where can I find more information about oil, oil filters, and other oil related information? bobistheoilguy.com's forum is the best source for this type of information. The folks on that forum eat, drink, and sleep oil information. Obviously there is good advice meeted out on NASIOC, but the folks on BITOG back their advice up with hard data and facts rather than personal impressions.

Editors Note

This post was created because I wasn't able to find a good oil FAQ. I came up with the text based on LOTS of searching here and the internet. Upon reading this you should have an idea of what type of oil best suits your needs. The manufacturer is up to you.

If you find an error in this FAQ, please PM me with factual details and I will update this post. If you feel this post is missing an important or common oil information item, let me know and I will research it and update this post.

* Registered users of the site do not see these ads.

[vile]

u sure have lots of time to put these faq together

good job on them though

they sticky in any of the forum? never really looked

[Unabomber]

When you are in the military and pull 24 hour duty stuck in a room with Internet access, you get my FAQ pages! 6 of my FAQ pages are stickied in the Newbies & FAQs Forum, but this is my first attempt in the Service & Maintenance Forum. I am quickly running out of mods to "FAQ", so I decided to branch out a little and a rash of oil questions in various forums were the catalyst for this post. This one only took 5 hours to do. Thanks for noticing!

[armand1]

ub: a while back I did a cutup study of the Subaru OEM vs PureOne filters. It's in this thread, which also got some good comment by others on the filtering efficiency of different filter materials, etc: http://forums.nasioc.com/forums/show...hreadid=310181

[Unabomber]

Thanks for pointing out your filter test, I added it to my post. The bobistheoilguy people are providing some great advice that is boosting up this post as well.

[Mike Wevrick]

Great FAQ!

Originally posted by Unabomber

What about extended oil changes when using synthetics? Extended drain intervals are possible with synthetic oils. To find out at what interval your oil needs to be changed, you need to institute a system of oil analysis. Blackstone Labs provides analysis services to help you determine your oil change interval.

I would quibble with this a bit. Subaru manuals say synthetics are OK to use, but should still be changed at the regular intervals. Given that statement, I decided to stick with dino. (and the fact that I do not drive my car that hard--most of its miles are highway cruising)

"dino" for those like me that took a while to figure it out is short for "dinosaur" ie fossil fuel. (sometime misspelled "dyno")

[Unabomber]

I can't really argue with your quibble. I ain't saying it's right, but people do it. At $35 for a complete analysis, it really isn't saving you money either. I did one just for fun and found out the Mobil 1 Delvac I was using was just about worn out at around 8000 miles. Mind you this is the oil that long haul truckers use for around 50,000 miles. A case of 4 gallons cost me around $120 too! Needless to say, I have had a change of heart once the Delvac runs out. I will update my post with a "warning".

[Mike Wevrick]

Only 8000 on synthetic? What kind of driving were you doing?

(I have been doing the full 7500 on dino because I do almost entirely highway cruising; we have another car we use for city trips.)

[Unabomber]

I had 3000 pure highway miles due to two long trips. The other 5000 is a mix of highway/city. No drag racing, launches, auto-x, or other racing. My oil analysis results if you are interested. The only "problem" I had was a little fuel in the oil due to extended idling and my short trip to work.

[SteveS]

Not to go off onto a different tangent, but Mobil Delvac is designed for commercial diesel engines, not gasoline engines. Diesel and gasoline engines have different needs when it comes to an oils chemistry, etc. So while it won't necessarily harm your engine, it won't provide all you are probably expecting.

Steve

[Unabomber]

Good point, but to further elaborate, it was specifically designed for extended oil changes on commercial diesel engines. I assumed that since it was "fortified" for extended oil changes, it would allow me to do so on my WRX. Analysis proves otherwise. I also didn't take into account that those diesel boys have an oil pan with a greater capacity than our gas tanks either! They also generally use dual filters with HEPA filtering capabilities or better. To be honest, Delvac was an expensive mistake. I ordered my WRX, and in the 3 week waiting interim, ordered many "accessories" for the new car to satiate my Subaru lust until it came in.

[neuspeed]

Another friend of mine, well when he goes to the oil change the dealer resets his ECU for some reason why is that? Also how do you reset the ECU in the WRX without losing the radio stations.

[Mike Wevrick]

There is no reason to reset the ECU when doing an oil change. I doubt you can do it without losing the radio stations.

[neuspeed]

EFI fuse?

[vile]

Originally posted by Unabomber
When you are in the military and pull 24 hour duty stuck in a room with Internet access, you get my FAQ pages! 6 of my FAQ pages are stickied in the Newbies & FAQs Forum, but this is my first attempt in the Service & Maintenance Forum. I am quickly running out of mods to "FAQ", so I decided to branch out a little and a rash of oil questions in various forums were the catalyst for this post. This one only took 5 hours to do. Thanks for noticing!

good to see our tax money going to good use, hehe

here's a suggetion for two more of your FAQ

1. sparkplugs
2. a maintance schedule table, seems like people don't read the manuel, but prefer to read here

ok, intermission over, get back to talking bout oil now

[Unabomber]

Thank you for the suggestions! Oddly enough, I mentally decided on a spark plug faq and a coolant faq as my next tasks! I even considered the maintenance schedule, but dismissed it. I passed on this idea because I try to make my faqs fairly Subaru generic and don't want to copy and post 900 different maintenance schedules. After the other two faqs are out of the way, I just may do it anyway though. The only reason for this is if I see one more "What do I do at 30k?" post, I may put a gun to my head.

[Max Umbarger]

There is always controversey about brands distributing their brands under other names. Is there any info introduced to your knowledge? I have a family member who worked in an oil refinery back in the 50's, and he says the same oil went into quite a few different oil cans. And back then there were probably only 5 different brands of oil. Of course there were those 'gas station' brands!

I have searched on and off for a few years and never come up with anything really

Max

[SteveS]

I won't go into specifics, but yes, this happens, and probably more often than most people realize. Do you really think that GoMart (fictional) has a lubricants plant? Ironically, or more likely surprisingly, it's not limited to off-the-wall brands, either. The formulations may be exactly the same, or they may be different if the 'customer' has some specific formula.

Steve

[Unabomber]

My Walmart nicotine patches are helping me quit smoking right now (so far so good ), and I am 99% sure they don't make them. They are like 40% cheaper than the Nicotrol ones though for the SAME THING. If memory serves, Consumer Reports did a small expose on battery manufacturers once. They stated that there were only like 3 companies in the world that made small consumer batteries (C, AA, etc.) and they managed to track down who made Walgreens Drug Store and a few other rebranded batteries. Very interesting. Though not entirely applicable to this thread, rebranding DOES occur. Sadly, we don't know who makes what in the motor oil world. Unless we have any oil industry types lurking here willing to spill the beans!

[STiMULi]

pulled from the Impreza (.pdf) manual...

(This information has probably been mentioned on the site 1 million times. Itallics are my edit. Because I live in the desert, I feel it can not be stressed enough)

The proper viscosity helps vehicle get good cold and hot starting by reducing viscous friction and thus increasing cranking speed.

NOTE:

• When replenishing oil, it does not matter if the oil to be added is a different brand from that in the engine; however, use oil having the API classification and SAE viscosity No. designated by SUBARU.

• If vehicle is used in desert areas with very high temperatures or for other heavy duty applications, the following viscosity oils may be used: API classification: SL or SJ. ILSAC classification: GF-3. SAE Viscosity No.: 30, 40, 10W-50, 20W-40, 20W- 50

[santofontana]

Originally posted by SteveS
Not to go off onto a different tangent, but Mobil Delvac is designed for commercial diesel engines, not gasoline engines. Diesel and gasoline engines have different needs when it comes to an oils chemistry, etc. So while it won't necessarily harm your engine, it won't provide all you are probably expecting.

Steve

Mobil is now repackaging their Delvac 1 as M1 Truck and SUV formula 5w40, so they seem to think it works in gas engines.

The Delvac 1 will last longer each interval it is used. I would suggest going 3 intervals of 6,000 before doing a UOA and determining OCI.

http://theoildrop.server101.com/ubb/...;f=11;t=000192

[STiMULi]

I got my 2005 Alpine White today and I had a chance to meet the Subaru Rep for the Phoenix Arizona area today. I quickly started a conversation about oil changes and oil type.

This is not to say what is right or wrong but this is what he said is right and I guess it will make him happy and presumably me as well:

Change the oil every 3000 miles no matter who says what.

Use Dino-based 10w-40 oil at the first oil change until 10000+ miles. He stated that Synthetic Oil is not as good as Dino-based oil in helping the seals "set".

He says that Synthetic could be used after 10000+ miles. He recommended 10w-40 or better

He also stated use only Subaru Filters. If it keeps him happy, I'll do it

[santofontana]

The prob with dino 10w40 is it tends to have a lot of shear instable viscosity index improvers. But his adive doesnt seem bad considering you are in AZ and wont be leaving the oil in for long.

As far as not going over 3k miles, thats crap. Synthetic oil are used in alot of HIGH end cars in europe (germany) and they have OCIs of over 10k regularly.

You can actually save money with syns. UOAs cost some too, but theyre good entertainment at the same time.

[Maicca]

Since ScoobyMods has now gone "pay-per-view," those links no longer work.

Quick Q, tho.......... Scooby mods stated that the transmission takes 3.75qts........is it 2.75 qts or 3.75?? Your FAQ doesnt address the quantity of the transmission, diff, or transmission.


And no, I don't have an owner's manual to check

[STiMULi]

What, if any, is the additive that is added to the original fill form the factory?