Recommendations on oil and fluids for 93 Legacy SS

[BoneIslandScooby]

If you don't like reading, skip it and just give me your recommendations on oil, fluids, and maintenance on a 93 Legacy SS I just bought. If you want a little background, read on. Thank you.

I just bought my first Subaru, though have been a member of several Subaru sites for years now. I finally found the right deal and actually was able to buy it before somebody else got to it. In my day, I have missed out on several unbelievable deals, and I wasn't going to let this one slip through my fingers. In any case, as some of you know from other posts I've made, I've purchased a 1993 Subaru Legacy Sport Sedan in fairly good condition. Of course, after such a long search, I now want to protect my investment.

I was thinking of doing an oil flush and change. If possible, I want to make sure to clear out any coking from oil in turbo. I also wanted to change the transmission fluid and any lubricants for the rear differential, as I assume that front and center diff lube is taken care of by changing transmission fluid. Correct me if I'm wrong. When possible, I will add a transmission cooler. I will also pressure test cooling system and possibly flush then change coolant. What fluids, especially oil, do you recommend for this vehicle? Any other recommendations for maintenance before I put any significant miles on it? Don't know if timing belt has been changed, but will ask mechanic.

Let me give you all some background. This car had 119, 419 miles when I bought it, the last 4,000 of which have been put on the car in the last 7 years. This is according to the previous owner, though I tend to believe it, because that is typical use here, as long as you don't drive out of town. Many people use their bikes to get around here. Add to this the fact that I would always see it parked in the same spot, the 7 years I've lived here, and have never seen it around town except once. I keep tabs on every Subaru in town, and I always notice them. Anyway, during its last 4,000 miles (or last 7 years) the car was used mostly for short trips in town. We have a hot and humid climate here, and there's plenty of salt in the air from the sea, which is never farther than 1 - 2 miles away from any part of our beautiful island. The previous owner was a real estate agent and certainly not a racer, nor a Subaru enthusiast, nor a gearhead, and certainly not an experienced owner of a turbocharged vehicle. Basically, he happened to know that the car had a turbo, but that was it. Translation: there was probably no cool down period before he shut off car, then again he may never have heated up turbo enough to cause coking of oil. The shop that worked on and maintained this car is a simple no-nonsense shop. It is not a shop specialized in Subarus nor in turbocharged vehicles. I don't know if there are any in town. All that said, it SEEMS that this car was well maintained for the most part. I will speak to the owner of the shop where it was maintained and one of the mechanics who used to work there to try to get some more background on the car.

[Legacy777]

Congrats on the new car.

I personally wouldn't get too worked up about "oil coking" and that jazz because the turbocharger has a passive cooling mechanism with the convective heat transfer through the cooling system. Plus, most modern oils are sufficient to withstand temp related breakdown during normal driving, which it sounds like this guy did.

I have used flushes in the past, however unless you have a specific problem you're trying to fix, I would just recommend draining the fluids and going back with new fluids.

Is this an auto or manual trans? If manual trans, I'd suggest Subaru Xtra-S trans fluid. If it's an auto, just run a good quality Dextron IV or higher compatible transmission fluid. It wouldn't hurt to use synthetic as it resists temperature breakdown better, and the auto transmissions are known to build up heat.

I'd see if you can get any past maintenance records for it and then decide from there on what you want to go and replace.

[BoneIslandScooby]

Anything? Want to shop and see if I can get what I need locally, or if I have to shop online. Florida Keys, hot and humid, car climate. What's the best oil I should use? I've searched, but the threads I've found are all over the place as to brand and viscosity. Maybe somebody in Florida has some advice as to what worked best for them?

[Legacy777]

For parts, I prefer buying Subaru parts vs. auto parts store brands, so depending on what you need to replace decide then on where you're going to get it. If you need to replace the timing belt, water pump, or oil seals, I'd suggest getting them from one of the online subaru dealers, www.subarugenuineparts.com www.subaruparts.com www.1stsubaruparts.com

There really isn't a "best" oil. Oil preference is really down to personal preference. I use mobil (non-synthetic) 10w30 in both my subarus here in Houston and it's fine. It's plenty hot & humid here. I will probably switch to synthetic once the new legacy motor is broken in. If you're planning to drive your car hard, then going to synthetic probably isn't a bad idea since it resists thermal breakdown better. If not, non-synthetic is ok.

[BoneIslandScooby]

Josh, thank you. High heat here in Key West, but I doubt this guy really pushed the car much. It was originally from Colorado. Anyway, he's probably never changed the auto transmission fluid, so it's probably due. I'll go full synthetic, and I'll probably add a transmission cooler to boot. Just wondering if any particular brand is recommended. Similarly, how about the oil? Are any, in particular, known to work better in these engines? Any to avoid? Being in high heat should I go with anything other than 10W-30? On the Saab 92x site many people shy away totally from Mobil 1 for example. I'm thinking maybe Castrol Syntec? I'll take your suggestion though and pick among the major brands. I'll try to find the best balance between cost and quality. I was writing this already when you posted.

[Legacy777]

As for trans fluid, Redline D4 synthetic is what I had run when I was still auto.

Engine oil....I've tried all the major brands, and regular mobil oil was the one that I didn't seem to burn any or much oil, so that's what I've stuck with over the years. So yeah....try what you want out. As long as you change the oil regularly it should be fine. The big thing is try to stick with one brand since the additive packages are different.

BTW, the average temps here in Houston are hotter than Key West, so you'll be fine with 10w30.

[James614]

For what it's worth, I run 10W-30 in my Touring Wagon year-round in NC (hot, humid summers, mild winters that may touch freezing once or twice). Before I started auto-Xing, I ran whatever synthetic/blend was cheapest when I went to change it. Since I started auto-Xing, I stick with 10W-30 and just run high-end full-synthetic, and she's perfectly happy.

Only time I ever saw a need to switch to a different weight was when I lived in PA, in the winter 10W-30 ran pretty rough in the mornings, so I would use 5W-20 November-March. But anywhere south of Virginia shouldn't need to worry about that.