Synthetic or regular oil?

[TeamPanic]

That is the question. Also what brand of oil would you reccomend to put in a 99 Outback? While we're at it, is there a special kind of coolant that you should use? Thanks guys!

[forester2002s]

Oh boy, Oh boy! Here we go again.

 

This question comes up with monotonous regularity. Just check down the page, and you'll see the most recent one. Or else do a search for 'synthetic oil', and you'll find more info than you can digest.

[Commuter]

I posted this almost exactly 2 years ago when a similar question was asked. (A search didn't turn it up. Probably dropped off ezboard back when.)

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I'm surprised that this topic didn't garner more comments. On some boards, this would have ignited a lot of discussion!

 

It's virtually impossible to define a "best" lubricant since the real world throws so many variables at us. Hence, this topic usually ends up as a bunch of people's opinions, experiences, hear say, a bit of (usually suspect) test data thrown in, etc.

 

I've been delving into engine oils to some extent over the past couple of years, ever since I decided to try one of those oils with "special additives". Let's see if I can summarize my findings. In other words, here is my opinion.

 

The quality of the lubricant it important, but probably the more important thing is to "change" the lubricant periodically. If one wants to just stick with low cost dino oil, that's fine. Personally, I'd avoid the "no-name" brands, but other than that, you are probably fine to choose whatever you like. For the engine, change the oil and filter according to the manual and you should be good to go. Make sure you keep within the manufacturer's recommendations for grade and weight as indicated above.

 

People are aware that their engine oil needs regular changing, but many tend to forget about all the other fluids in their car. Many of these "other" fluids only need to be changed every couple of years. It's easy to forget or lose track (unless one is relying on the dealer and their servicing schedule.) Other fluids include transmissions, differentials, brake system, power steering, radiator, perhaps hydraulic clutch, etc. I shake my head when I hear of automatic transmission problems on (say) 8 yo cars. The ATF probably got changed once around the 2 or 3 year mark while still under warranty, then got forgotten about. Owners don't have a clue when the last fluid change was done and blame their car for being a piece of junk because they now have a $1000+ bill for transmission work. (Note - there could be many reasons for transmission problems. I'm just making a point.)

 

If you want to consider synthetic fluids, you are now into another realm. There is much debate regarding synthetics. I'm not going to get into it (much) here except to say that one is probably best to do a little studying, if so inclined. In general, I'd say that they are superior. Can you extend change intervals? Lots of debate here. I'm going to stay out of it for the moment. What brand to chose? I'll leave that up to you. One of the more commonly selected brands is Mobil 1. It is generally regarded as a quality product AND it is readily available. You can find it a Walmart.

 

The ONE place to be wary about the use of synthetic oil is in a manual transmission. A manual transmission has two conflicting needs from the oil. First, it requires lubrication for the bearings and gears (which synthetic provides very well). Second, it needs SOME friction for proper synchromesh unit operation. Synthetic oils can be "too good" and not provide sufficient friction, thus the synchos take longer to do their thing and grinding can result. One oil that supposedly addresses this is the "NS" products from Redline.

 

I consider the oils like Redline, Amsoil and Royal Purple to be in a different class from the "big boys" synthetics. These are smaller companies usually concocting special blends for higher performance. Just keep in mind that "higher performance" may or may not be what you need or want for your daily driver. Some of these oils don't even have the usual industry certifications. (I've seen a lot of discussion about this regarding Amsoil.) Availability is another issue. If you are going to go this route, you have a choice. Become familiar with the products and make an educated decision, or alternately, place your trust in "someone" and accept the outcome.

 

There can be many valid reasons for considering an upgrade of your car’s fluids. Climate, towing, offroading, auto-cross, etc. Each person will have to decide for themselves the “value” that comes with the associated cost.

 

 

One point I would like to make concerns the engine oil filter. A quality filter can go a long way towards reducing wear on an engine. All indications are that the Subaru Purolator filter is actually a darn good filter. If you want to move a step up, I'd suggest the Purolator PureONE filter. (If you buy a case of 12, you should be able to negotiate anywhere from 25% to 50% off list.) I'm also a fan of the use of oil filter magnets. A one time purchase item. The magnet will capture "any" size of magnetic particle, even those that would flow right through the filter.

 

You can get even more esoteric with lubricants if you want. I've come come across a few people using Motul products. Personally, I'm using SynLube. (Talk about a product that is "out there"! )

 

The prior point about longevity of the drivetrain vs the rest of the car is a good one. One can go nuts making their drivetrain last virtually forever if they want to, however, the springs will probably be poking out of the seat and the seat will be probably be sinking through the floorboards. A certain "balance" needs to be struck.

 

So chose your lubricants and fluids wisely. Right now, after typing all this, I think my "fluid" of choice is a beer!

 

 

Commtuer

[Setright]

Filter magnets...hmmm..aluminium engine block, head, and pistons. Both non-ferrous. The only ferrous metals are the backing plates of the plain bearings in crank and cam, and the piston rings. The "white metal" outer coating, and copper "primer" are hardly going to stick to a magnet.

 

Okay, the cast-in cylinder liners are steel, so the magnet may well catch a few particles, if your bores are being worn.

[Commuter]

There are enough "magnetic metalic" surfaces that wear to matter. Rings, cylinder sleeve, camshaft, crankshaft, tappets, wrist pin, etc. The bearing itself might be non-magnetic, but the part turning against them usually isn't.

 

Trust me, I've cut open enough filters over the past few years now to see what the magnets collect.

 

Commuter

[Setright]

Okay, so does it collect bits, or is just a fine layer?

[slo5oh]

on magnets:

I put one on my '98 when I bought it with about 60k. The first 2 oil changes coated the magnet enough that the roughly 2mm diameter magnetic shaft was about 4mm. On my last 2 oil changes I have had almost nothing stuck to the magnet. I am now at about 110k and the last oil change was last weekend.

 

For oils I have used, here's what I have found:

petrol based - garbage

Redline 5-30 wt. - too thin when cold, would get some valvetrain noise at 2k or more until engine warmed up.

Mobile 1 5-30 wt. - works great, no problems

Mobile 1 10-30 wt. - works great, no problems

 

I run synthetic oil because I drive a lot. I probably put 3k on my car a month, so with full synthetic I feel safe running it about 3 months (roughly 10k) between oil changes. As it is I'm spending less for an oil change then you pay at jiffy screwb, or pingsoil. It's $20.02 for 5 qts of Mobile 1 at Walmart and I can pick up a good filter for about $1.50. Their generic (supertech, I think) is a good filter.

[slo5oh]

Okay, so does it collect bits, or is just a fine layer?

Mine had sludge stuck to it. You wouldn't even know it was metal. It's only the stuff fine enough to slip through your oil filter.

[Setright]

If I can find one, I might give it a try.