Which oil?

[Justins91ss]

Just seeing what you guys are running oil wise? Just bought my 91 with 318k kms just put in castrol edge 10-30 and when i get back to vegas ill use castrol syntec 10-40. Just was seeing if theres any preference as a community or more of a case by case thing, thanks

[93forestpearl]

Rotella-T 15w-40


zinc is good

[Subaru Psycho]

Royal Purple 5w 30 unless you are WOT for extended periods of time, then you might want to go thicker.

[kimokalihi]

The factory service manual recommends 10w30 or 10w40.

[Justins91ss]

Yeah i was reading the manual the other day and 10-30&10-40 dident make much sense for a new car imo.. Mine has alot of miles so i was going to go with a thicker oil as the previous owner just used a cheap 5-30 synthetic. Subaru dealership reccomended 5-30 syntec blend which is what they put in when i got the car bcuz it had a stripped drainplug. Ill put in 10-40 when i get back to vegas due to the heat and the amount of miles.

[SLODRIVE]

Don't believe the hype about thicker oil, all it'll do is waste power and give you a longer "dry start" period upon startup. (as in, increased engine wear) I've been running 5w-30 in all 6 Legacies around me, most of which have well over 200k on the odo, and include N/A and turbo cars. The turbos and the N/As that hold oil get Mobil 1; the leaker gets Castrol GTX.

[kimokalihi]

I put 10w30 or 10w40 (can't remember now) in my legacy but I was going by that chard and not a hype. I didn't even know there was a hype on thicker oil lol.

[Justins91ss]

So you woudent run a 40or50weight oil in 115-120degree weather? Hmm ive always thought you would wabt to run a higher # due to the heat and it being a turbo car?

[ericem]

5w-40 rotella here. Royal purple sucks, way to thin for some reason randomly my HLA's would start clattering with the engine hot, and it did burn. No issues with rotella.

[Justins91ss]

Thats the shell brand correct? Havent seen too many places carry out here in the pac nw

[SLODRIVE]

So you woudent run a 40or50weight oil in 115-120degree weather? Hmm ive always thought you would wabt to run a higher # due to the heat and it being a turbo car?

Nope. I run 5w-30 in 100+ degree heat in the turbo Legacies, Rob's built STi, and my GTO, none of which are babied. In fact, the white SS has over 80 lbs. of oil pressure when hot. For the most part, any modern 5w-30 shouldn't have an issue, unless your bearings were so wasted that you couldn't maintain oil pressure, I suppose. I have run 0w-40 myself before and had no known issues, but in the end couldn't justify it. 5w-40 Rotella's some good oil IMO, but I'm wary of any zinc from that diesel oil fouling stuff up.

[jefferson]

Amsoil 10 w 30. I have thought about the 5w and 0w oils, then my last oil change I found one of the squirters in the bottom of the pan and figure I need whatever extra pressure it gives me.

[evolutionmovement]

I use Mobil 1 5/30. Changed a minimum of every 7500 miles and beat the hell out of the car with daily redlines through 3rd, weather ranges from 20 below to 100+F, bad traffic, 130mph+ indicated speed, J-turns, high speed runs down gravel roads. Tore the engine down at 247k miles (melted valve) and found the top end like new, crosshatching in the cylinders, bottom end I would bet could have done another 100k. It's all I use and I have no reason to change.

I tried the 0w back on the GL, but that stuff pissed right through and found any leak it could. It seriously pours like water.

[Justins91ss]

Hmm i see, well i think ill stick with the castrol edge 5-30 for now since thr first two oil changes at 3k miles it came out as clean/clear as it did going in. Then maybe will try a lil thicker oil and see how that worksout, thanks for your thoughts/opinions.

[Subaru Psycho]

Mineral based oil breaks down at 300 degrees. So keep an eye on that oil temp gauge if you are using synthetics.
Heating oil over 225 degrees cuts the oil life in half and every 10 degrees over 225 cuts the life in half again for each 10 degrees. Running oil at at the temperature of 170 to 200 is ideal.

[kimokalihi]

It's a stock car so I don't think he's got an oil temp gauge.

[Justins91ss]

Yea its just a commuter i dont need a "racecar" id choose a different car to start with if i was..

[Subaru Psycho]

If he doesn't have an oil gauge he can watch the temperature of the engine. If its stock it has an engine coolant gauge. If the oil gets too hot it will thin out and not hold the same lubricity factors it once had. Which will cause the engine to overheat.

[SLODRIVE]

If he doesn't have an oil gauge he can watch the temperature of the engine. If its stock it has an engine coolant gauge. If the oil gets too hot it will thin out and not hold the same lubricity factors it once had. Which will cause the engine to overheat.

No offense, but where are you getting your info from? If you truly got an engine hot enough to cook motor oil in the way you're trying to describe, you would have long ago melted your Subie motor. There's honestly no oil made that won't survive any halfway sane oil change interval. I'm not sure of your background, but in over 20 years in automotive I have NEVER seen an engine overheat due to oil breakdown.

[Legacy777]

Just an FYI for those running or wanting to run Rotella or any other oils with zinc......zinc is not good for catalytic converters. Prolonged use with cats could contaminate the cats.

[Justins91ss]

Which oil would u suggest? I have to keep my cat since california is super strict on that..

[SLODRIVE]

Which oil would u suggest? I have to keep my cat since california is super strict on that..

Mobil 1 is great motor oil, regardless of what the crackheads on NASIOC say!

[Legacy777]

I just run the standard mobil dyno oil. Have been running it for years without any issues.

[tturnpaw]

Thats the shell brand correct? Havent seen too many places carry out here in the pac nw

Autozone has it. Buy it for my powerstroke.

I've always been a fan of castrol gtx when I don't have the cash for synthetic. But when I do I usually live by mobil 1. Royal purple and amsoil have not proven one bit of lubrication or anti breakdown advantage over mobil 1 so thus why spend the money when every engine I've ever assembled takes it kindly?

In my 1jz that I was drifting it was 80* out and I never saw the oil temp go above 195* during any of the runs. Stock twins hated life though haha.

[Justins91ss]

Dident care much for the 10-40 bitog had great reviews on castrol german 0-30 syntec so ive been running that with good results thus far.