Best Synthetic Oil to use?

livestrong14 · Post by **livestrong14** » Fri Mar 02, 2007 12:50 am

I am getting ready to do an oil change on my 91' Legacy SS with an Ej20G swap. What synthetic oil should I use? What is the best 'bang for the buck'? Royal Purple? Mobil 1? WHAT?

-Devan

Post by **DLC** » Fri Mar 02, 2007 1:44 am

Best is yet to be proven. Get something you can find easily and you'll probably always be good.

I use Mobil 1.

evolutionmovement · Post by **evolutionmovement** » Fri Mar 02, 2007 3:40 am

Yeah, Royal Purple's hard to find. I don't think you can go wrong with Mobil 1 even if it's a lousy corporation. I've never used anything less after driving my old GL several hundred miles at near redline with less than a quart when I got home and the car went on to run fine for a year before it when it went to the junk yard (tree fell on it).

Innovative Tuning · Post by **Innovative Tuning** » Fri Mar 02, 2007 3:35 pm

Oil testing has shown me that in real world use Mobil 1 doesn't hold up compared to Amsoil, so I use Amsoil. For most cars the extra resistance to breakdown doesn't really matter though. I'm harder on my cars than the average joe.

shemoves · Post by **shemoves** » Fri Mar 02, 2007 6:11 pm

I used M1 full synth in my old WRX, and had noticable shearing after 2k miles. It felt great when new...so is prolly a good oil for 1.5k to 2k OCIs.

Although it is not within the rec. spec range in numbers, German Castrol is known to be a very thick 30 weight, and just an outstanding oil...I would consider this to be the best bang for the buck oil out there. It can be hard to find, though.

Whatever oil you pick, keep doing UOAs until you find the one that works (will take some time obviously). In the meantime...search here: http://theoildrop.server101.com/forums/ ... .php?Cat=0

dzx · Post by **dzx** » Sat Mar 03, 2007 5:12 am

I'm not a big fan of royal purple since the time i used it and found it all in my intercooler.

entirelyturbo · Post by **entirelyturbo** » Sat Mar 03, 2007 6:15 am

Do you know what oil is in your engine now?

BAC5.2 · Post by **BAC5.2** » Sat Mar 03, 2007 11:56 am

Motul.

entirelyturbo · Post by **entirelyturbo** » Sat Mar 03, 2007 4:12 pm

Then he should keep using the Motul IMO.

Changing oil brands = bad.

gto7419 · Post by **gto7419** » Sat Mar 03, 2007 6:14 pm

Motul is very good stuff - its just super expensive. Its the only oil I run in my shifter karts.... I also going to start using their brake fluid in the karts - its supp to be EXCELLENT.

Danny

BAC5.2 · Post by **BAC5.2** » Sun Mar 04, 2007 2:13 pm

It IS excellent. RBF600 is far superior to any fluid I've ever used. Even ATE SuperBlue!

I wasn't saying he was using Motul. I was answering the question about which is the best synthetic oil.

boro · Post by **boro** » Sun Mar 04, 2007 7:52 pm

BAC5.2 wrote:It IS excellent. RBF600 is far superior to any fluid I've ever used. Even ATE SuperBlue!

I wasn't saying he was using Motul. I was answering the question about which is the best synthetic oil.

is it safe with ABS? I am looking for a harder fluid.

gto7419 · Post by **gto7419** » Sun Mar 04, 2007 8:25 pm

boro wrote:
BAC5.2 wrote:It IS excellent. RBF600 is far superior to any fluid I've ever used. Even ATE SuperBlue!

I wasn't saying he was using Motul. I was answering the question about which is the best synthetic oil.
is it safe with ABS? I am looking for a harder fluid.

I believe the correct question, is, "is it safe with my rubber seals?"

I also believe it is DOT 4 rated, so it *should* be safe with your seals and your abs....

DOT 5 will destroy normal seals in brake systems and should be avoided...

Danny

shemoves · Post by **shemoves** » Mon Mar 05, 2007 12:28 am

I dunno about seals, but I use RBF600 in my STi and it seems to work great. ABS seems to function the same as stock...but I've only seen light ABS on a couple occasions.

Post by **Legacy777** » Mon Mar 05, 2007 6:39 pm

This should really go in the brakes forum.....but the main issue you run into with the Motul brake fluid, besides cost is the fact is absorbs moisture much more quickly then some of the other fluids. So if you just want to stick brake fluic in and not worry about it, then this stuff may not be the stuff you want.

It also depends too on your climate. Humid/moist climates....you should really change your fluid more frequently.

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Best Synthetic Oil to use?

Best Synthetic Oil to use?