06 Forester-What type of oil, how often to change?

I should add that I will be getting a 06 Premium or LL Bean, not the XT.

Your question is a good argument starter! You may enjoy some of the info and forum discussions at

. Officially, you should use what the manual suggests - likely 5-30 SM or whatever.

I use synthetic in my '03 OBW and my '06 WRX. 5w-40 and do chnages at

5-6K or twice year, whichever comes first!

Carl

That's pretty much my philosophy. I switched all our cars, even the ones with over 200K miles, to synthetic a few years ago. I worried about seal leaks on the old ones at first, but none showed up.

What impressed me was our 2002 Toyota. I changed it from dino juice to synthetic at 15K miles, by which time I noticed traces of varnish on the upper part of the dipstick where it wasn't bathed in oil. I was doing the oil change at 60K the other day and noticed the varnish was gone, even though that part of the dipstick only gets random spray.

Mike

Hi,

Oil type, change interval, viscosity, are all hottly debated topics and you will find many different opinions.

My opinion is as below:

Basically, when the engine is new and tight you want to use lowest viscosity oil recommended for your particular application/climate, be it regular or synthetic oil. Then, as the engine wears, you want to gradually, and very slightly, increase the oil viscosity to compensate for reduced tightness. When the engine is old and blow-by is significant you want to use thicker oil and change it more frequently.

At this point in time, usually around (80k-150k- depending on engine type, make, displacement) I switch from synthetic to diesel regular oil and change it very frequently (2000-2500 miles, or so). It makes little sense to keep synthetic for 7500 miles in an engine that will contaminate it badly after only 1500 miles or so. Use of good quality filters makes a big difference in slowing down engine wear, so don't overlook this aspect.

As you see, mine is a flexible and functional approach to getting the most out of an engine, both in terms of longevity and fuel economy.

I think 5w-30 synthetic is a great oil viscosity to start with on a new Forester in Colorado.

MN

Here is a schedule illustrating my approach that you may want to try on your Colorado Forester.

1). At 1,000 miles switch to synthetic 5w-30- to be changed at 5,000-7,500 mile intervals 2). At 30,000 or 50,000 miles, switch to a slightly thicker 5w-40 synthetic, to be changed at same 5,000-7,500 mile interval 3). At 100,000 miles increase oil change frequency to every 3000- 5000 miles 4). At 150,000, or so miles, switch to 15w-40 diesel type oil and increase change interval to 3000 miles, then 2500 miles.

I've had very good results with a similar approach (though I switched to synthetic at 50k and never went more than 5000 mile intervals, and used heavier viscosities). My old GM 2,8L v6 has more than

185k miles on it (first 100k miles were made in extremely hot dusty Southwest climate, then 85k of mostly mountainous Sierra driving with very frequent climbs from 100 to 7300 feet

- Donners Pass). Despite its venerable age it uses virtually no oil (!) and still runs very very strong. These engines driven under far less taxing conditions would have an average lifespan of

130k-150k. I attribute my very good experience with this American engine to the oil regimen. With a Subaru engine, and good oil regimen probably hundreds of thousands of more miles are possible.

MN

superb post.

Carl

Yep. Folks who THINK their car's oil is burnt or dirtier after switching to synthetic are actually seeing varnish suspended in the oil instead of being left behing on internal parts. Whether varnish film would really be a problem is a diffent debate but that IS why the synth. may look darker even at the same change interval as 'dino' oil.

Carl

Thanks for all of that information. I already printed it out to use as a guide for oil changes. Now I just need the Forester :) I'm going by a dealership next week to see what I can work out.

Hi,

As has already been noted, "what type of oil" questions generally spark much debate!

Having said that, let's look at the oil change interval. When you get your new car, read the manual, and do what it says! Whether dino or synthetic, you're gonna need to change at the manufacturer's recommended interval in order to preserve warranty coverage.

Once the warranty's up, you're on your own. Many suggest longer intervals w/ synthetics. Some suggest oil analysis to determine the intervals. My VERY limited experience w/ oil analysis is I can do an oil change for not much more money, and KNOW I've got clean oil for x more miles. But that's a matter of opinion.

Much has been said about when to switch to synthetics, when not to. Several cars come from the factory w/ Mobil 1 already installed. Mobil claims there's no need to go thru the "break-in" regimens often suggested. While I don't agree with all this guy has to say, you'll find an interesting read at

which you may ormay not find to be in agreement with what others have said over theyears.

As has also been reported, synthetics have a very good reputation for cleaning. This is one of the reasons it's sometimes suggested a high mileage engine not be switched over: oil leaks can occur where old crud is cleaned out, old crud that was actually doing the sealing! A gentleman who posted here for some years referred to this as "the laxative effect." As good a term as any!

Some claims have been made of great increases in fuel economy when switching to synthetics. I won't argue that some cars MAY get better mileage, but my experience, carefully documented, indicates no more than a tiny increase (like around 1% or less over 10s of 1000s of miles) in economy. Claims have also been made that the engine runs 10s of degrees cooler. In street use, with a properly functioning cooling system, the t-stat will regulate the temp far more tightly than that, so while I'm not saying it can't happen, I'm just skeptical.

There are also many claims that wear is greatly decreased using synthetics. I haven't seen a side by side test yet to prove that beyond doubt. But the big 3 US diesel oils, Delo 400 (Chevron), Delvac (Mobil) and Rotella (Shell) have all passed MILLION mile tests on big diesel engines (keep in mind the warranty on many of them is 600k miles or so!), and they're dino-based. So a dino oil isn't going to "wear out" your engine if you follow regular change intervals w/ good filters! My gut level feeling is synthetics probably DO cut wear IF you use extended change intervals, but with 3-4k mile change intervals, I doubt the average person will see any significant difference. I could be wrong.

As for my personal experience turned into opinion, Wal-Mart's cheapest dino oil, with a good filter, changed at 3000 mile intervals, will probably keep your engine going as long and with as little wear as an expensive synthetic run out to 7500 miles or so. I don't know how long you plan on keeping your car, but my '90 Loyale, which was terribly cared for by its first owner, lived its life on dino oil. It died at

360k miles of a non-oil related "disease" (serious pinging finally took its toll.) There's also a Camry in the driveway that has 234k miles and runs "like new." Changed religiously at 3500-3750 mile intervals using that oft-maligned Pennzoil. No oil related problems or excess consumption, etc. One of these days maybe I'll start a thread to compare high mileage engines as to dino or synthetic and change intervals...

So you pays your money and you takes your choice, as they say!

Hope you like your new car when it gets here!

Rick

Superb post! ;^)

Yeah, synthetic likely has only a few percent advantage over 'dino' oil if both are used in a reasonable manner. I guess I feel like ,with synthetic, if I'm a few hundred miles over, or if I need to urgently jump in my car and make a long trip and have no time for a needed oil change, the synthetic gives me an 'edge'. I think Consumer's Union tested some taxi cabs and pretty could find no wear if they just had oil in them! Of course, I think those cabs were kept in heated garages and likely do a lot more idling and fewer 'starts' than our cars - still an interesting test.

Can't argue with your experience!

Carl

Just my view and experience

Synthetic and dino oil both get dirty just as fast as the other! It's not the wearing out of the oil that causes the problems (Oil can last 20K miles of "wear" very easily), it's the corrosive combustion by products and carbon that "dirty" your oil that cause problems.

I tend to run semi synthetics as a compromise. Change every 10K kms (6200Miles) to keep it clean, but has that synthetic element if something did goes wrong (overheat etc.)

I have a Suzuki Cappuccino in my garage with 87K miles. Its a 660cc 3 cylinder turbo which revs to 8800Rpm (67 Hp at 6500). The manufacturers reccomend a standard dino oil, but changed every 3000 miles. I run a semi synthetic, just to cope with some of the heat stresses of that tiny little turbo (it's smaller than a hair dryer!). It's managed with synth all this time, and it's probably one of the more demanding standard factory road going engines ever made!

My last Subaru managed to get 280000 kms on a donaldson filter and fuchs oil pack form a local store - it cost about US$10 evey 10000kms (6200 miles) never had any engine work done, even after it lost all its coolant on a road trip when the radiator burst.

I tend to look at synths for demanding applications, and more regular oil changes for heavy traffic, or short runs.

The most important thing is to stop the micro-corrosion of internal components due to corrosive acids in the oil.

I also have a car with 72000 miles on, which has never had an oil change... kind of - I just keep toppping it up! It helps that it is 2-stroke :-) so it has a reservoir and the oil is fed through the BALL-bearing and is then consumed by the engine :-) This one is a 357cc 2 cylinder putting out 34Hp and 6000 rpm!

No wonder I like the quirky-ness of Subaru!

Allan Williams Whangarei, New Zealand