Which oil for Subaru Legacy?

[bfg9k]

Howdy everyone. I have a 98 Subaru Legacy (2.2L EJ22 engine, AT), 106k miles. I do ~6500 miles a year, 95% highway driving in the Boston area. While chasing higher gas mileage a few months ago, I switched the differentials and engine oils to synthetic, with Royal Purple 75w90 in the diff and, on a whim, Redline 5w30 in the engine. The redline is pricey, and I think the engine ran quieter and smoother on the conventional oil beforehand. The usual startup ticking noise is much louder with the Redline.

I'd like to switch it to something better for this engine, and do one oil change per year. Any suggestions? The manual recommends a 5w30 or 10w30. I'll be using the OEM filter as well.

 

[Doug Hillary]

Hi,
I tried three Mobil oils in my E25 Outback as follows;

Mobil 1 0w-40 (first 50k kms) - excellent with very little consumption

Mobil 1 10w30 (next 20k kms) - noisy at startup and consumed a little

Delvac 1 5w-40 (next 50k kms) - excellent with very little consumption and extended drains (20k kms)

I use Castrol's Transmax 75w-90 in gearbox and axle. It has been there for 122k kms and the shift quality is "as new"

My car is driven quickly over very long distances - a lot at around 30-40C ambient

Regards
Doug

 

[bigpaulo]

Don't know about the 2.2, but I have a 2.5 Impreza TS, and here's my experience

Mobil 1 5W30 OK, felt a big sluggish, some startup noise
Mobil 1 0W30 best engine response, noticeably more startup noise
GC 0W30 somewhat sluggish, least engine startup noise

All of these oils gave me decently quiet engine noise when warmed up. Mobil 1 0W30 gave best gas mileage by far (1-2 mpg more than GC).

My next test-experience, targeted for this spring... Mobil 1 0W30 cut with 2 quarts of Mobil 1 0W40 (should bring it close to hot GC viscosity).

And I have a 37 mile commute (each way) from Boston to the burbs and back, so I'm seeing your same climate! I hope this rain melts some of those huge piles of snow already!

Oh yeah... and if you're looking for a Redline killer, try the new Mobil 1 5W30 Extended Performance (has anyone around Boston seen this oil in stores yet? WalMart? AutoZone? P**pboys?) Sounds like that oil would be *perfect* for a yearly OCI, and yes, the OEM Subaru filter is renowned in Subie circles as the best quality filter (it's what I use, too).

IIRC, yearly OCIs are best made in the spring (warmer weather is easy on the oil, you'll have tons of reserves going into the bad winter months, and dumping it in the spring gets rid of all the water, sodium and other nasties accumulated through typical winter idling and driving).

[ February 03, 2005, 06:14 PM: Message edited by: bigpaulo ]

 

[bfg9k]

I was just in a store in Billerica buying Mobil 1 0w-40 for our Saab 9-5, and didn't spot the ext. performance version. I haven't noticed the extended performance stuff at any stores like Autozone or Lappen's for that matter.

I work in Burlington, for some reason there's a TON of auto stores on 3A in Billerica.

I am considering the Royal Purple 5w30 since it's about the same price as Mobil 1, again at yet another Billerica store. A 5w40 might be a good solution too for those times when I'm stuck on 95 in gridlock in August

 

[vvk]

Castrol GTX 10w30 so far is my favorite in Subarus. Engine really seems to run smoother and quieter. Also check UOA section -- I posted my results with Mobil 1, GTX and Motorcraft. Mobil 1 produced highest wear.

I am still debating if it's OK to use Castrol GTX in winter. My 1994 Impreza with EJ18 engine does not seem to mind the GTX HM 10w30 I has in there now, even down to 0'F. On the other hand, my 1998 Impreza with EJ25 engine does seem to run a little louder at start-up on very cold mornings, down to 0'F.

GC 0w30 produced OK wear but EJ25 did sound rougher with it vs. Castrol GTX 10w30.

Subaru of America has always warned against using synthetic oils. Recently they relaxed their position a little, saying that synthetic oils are permitted, as long as OCIs are kept as recommended.

 

[bfg9k]

VVK, do you think a synthetic blend would be a good choice for an annual change and 6500 miles? Not that the annual schedule is necessary, just convenient

 

[vvk]

quote:

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Originally posted by bfg9k:
VVK, do you think a synthetic blend would be a good choice for an annual change and 6500 miles? Not that the annual schedule is necessary, just convenient

---

If you only drive 6500 miles per year, you should be on "severe" schedule. Meaning oil change every 3-4 months. Oil type does not matter.

 

[rjundi]

Given your limited mileage = short trips and Boston highway = really city driving (lots of stop & go) you are likely in the severe range. That being said use any decent dino and change every 3750 miles or 3-4 months whichever comes first per Subaru.

 

[bfg9k]

You know, that's an excellent point wrt to qualifying for severe driving conditions. I was thinking the highway mileage made up for the lower miles...

Ok then, I'll ditch the synthetic stuff when it's warmer out (and I feel like I've gotten my big bucks worth out of it!) and replace with the Castrol GTX or one of the other conventional oils that people seem to like around here.

I was thinking of a transmission cooler as well to protect my newly rebuilt transmission...I think that'll get done this spring too.

 

[Norm Olt]

I have over 120,000 miles on my ' 92 SVX and I use & recommend $1 Chevron Supreme 10w30 @ 3K OCI's.

You might consider trying an Auto-Rx treatment on your oil if you have not done so: Subaru builds a fine engine and it can last a really long time with a little extra care.

Cheers!

Norm

 

[Garandman]

I used Castrol GTX on our 97 OB Wagons. We still have one. Now I use Castrol high Mileage as it is MUCH quiter on cold start. 156K miles.

 

[Garandman]

Did you install a trans cooler?

When we had our OBW engine apaprt at 140K for new head gaskets (a BIG problem with 2.5l Subarus) you could still see the hone marks in the cylinder bores and the heads were good.

So if you catch the head gaskets before they burn up they'll last as long as the 2.2l Subaru engines, over 200K miles. I have 158K now.

[ July 28, 2005, 07:07 AM: Message edited by: Garandman ]