trinituner.com

My oil changing times is near and need to know what to go with. So need some reviews, advice and corrections on what im typing here.

So i heard some talks about some oils that come in barrels or so designed for certain countries and oils that are from american shops which were made for that climate. Then saw a oil test between Royal Purple, Amsoil and Schaeffer's on a load bearing test. From what was seen, Amsoil was the first to fail, while Royal Purple did not even fail for the entire testing. Another test was done some other time by the place but was not there.

So im thinking to go with Royal Purple engine oil and as for many years of the garage that highly recommends it, have not heard of any engine failures on STi's and WRX's. Currently the car has Schaeffer's and its quiet and works smooth but thinking to just go with Royal Purple and done.


Now the gearbox has Royal Purple as well, but i've been told to use the Subaru Extra-S oil.....i do have the 5th gear grind when going at high rpms but this does not happen all the time, especially when cruising and changing gears like a slowmo...

I've noticed my clutch cylinder fluid is black, so its possible the rubbers are going or could be the fluid is dirty and never was changed as the car used to be used on weekends mostly.

QUESTION - Do you think i should drain all the fluid and flush it out and try new fluid and see what happens? Or change clutch master & slave cylinders? The fluid change wont be costly, but time is what i don't got


The diff oil, well im sure most of you guys with STi's can recommend the best to use as i wanna change that also so i know when i did a full oil change up.



Thanks in Advanced!

Also, the block is fully built up, doing close to 10,000kms

Get a clutch kit for both master and slave. I think the STI is 11/16 size rubber of the master and 3/4 for the slave... you can verify with your mech. The ones made by SEIKEN are cheap and good to use as compared to OEM.

As for oil it's your choice but I use Amsoil 20w50 in the engine and Amsoil Severe Gear with Amsoil slip lock in my wrx and it works well.

I use Amsoil 20w50 in d engine & Amsoil Severe Gear in d box.
Works fine for me.

I also use Amsoil 20W50 with no problems

np ftw

Gonna head down by Bird and do the changes. Think i might run the Subaru Extra-S in the gearbox tho.

747 TECHNOLOGIES wrote:Gonna head down by Bird and do the changes. Think i might run the Subaru Extra-S in the gearbox tho.

wise choice

Amzoil engine oil .... talk done

OK so went by Bird today to get my oils changed. Got some extra services done for no extra costs really. Excellent people!

Changed engine oil and filter, i used Amsoil 20W50 and K&N Oil filter.....So far, oil pressure is excellent, right through, engine runs smooth and nice.

Diff oil, used the OEM Subaru LSD Oil. Working nice as it should.

Gearbox oil, now i was thinking maybe my syncros really bad in 4th and 5th and instead of going at 130$ a quart for Extra-S, lets try the Redline mixture. Bird also recommended it since we dont know how long ago oil was changed or if its really just wear and tear and syncros going. I asked a few people who are making good power on their STi's what they use, most of which i asked use the redline mixture bcuz of its smoothness and some use amsoil with the sliplock.

Got 3 quarts of 75W90 Redline Gear oil and 1 quart of Heavy Shockproof redline oil. Was hesitant on expecting it to be smooth but i was amazed. All gears going in smoothly, no grating or grinding nothing. On the highway, i said it will be the ultimate test as its mostly when the car drives a bit after morning startup it grates, and 100% ALWAYS it did on downshift from 6th to 5th. SO i tried it all, no grating nothing, just perfect smooth upshifting and downshifting!

Very happy with the Redline oil. I believed the previous owner said it had Royal Purple. Was also told to go back with Royal Purple but upon asking what oil a few men used, i stayed off it and went with whats proven here.

Bird and Josh are good People.


What's the Oil Pressure like?

I have the Cosworth oil pump so i see higher pressures but i see 80-90psi on cold startup, and idle at 42-44psi when warm. Under acceleration its anywhere around 60-100psi and hard driving as i did today was at 110-115psi.

Thought it was my Defi gauge faulty but online reading i see most cosworth pump users get this pressure. For some reason, very few get lower.

Very happy with the car VERY HAPPY! lol

engine oil - amsoil 20w50
oil filter-oem
transmission- motul 75w-90 > OEM extra S > Amsoil transmission gear lube >>>>> red line anything IMO
Clutch - Super blue racing
Diff -OEM STI diff Fluid

Just kinda my set up lol but this is what i came up with after religious fluid changes for the last 2+ years

I've heard the motul is the best in the gearbox, will try that next gear oil change, which would be in 6 months. I prefer to change engine oil every 3-4 months max, and gearbox oil 6 months and diff oil every year as i use the car EVERYDAY.

Amsoil all the way.

Mechanic charge too much for the oil so just by it form a parts place.Use the K&N oil filter "better filtration"

How much oil does an STi burn for about a 2500-3000kms of driving?

Subaru says that up to a quart per 1000Miles is acceptable on an engine with some miles on it...

I hardly see any burn-off but I think it would depend on your type of oil as well.

i did 3000kms and burnt nearly a quart. Been doing alot of beach driving and traffic driving as well.

747, that engine may need rings boi !!! That's way to much burnt oil for 1800 miles. Lance may be correct,its seem more practical.

Got scared there, the dipstick fooled me....the engine was fully rebuilt when i got with forged internals etc and had about 10,000k on it....for some reason the dipstick read low and i put the quart and it read normal....this morning, im reading this and just decided to check it and realized i probably needed less than 1/4 of a quart for top up, now im over filled :'(

Subaru dipsticks can be misleading.....

I normally have to check 2-3 times to make sure the reading is accurate.

yea, im gonna have to start doing that from now one

So wa bout shaeffers

Heard its a good oil as well.

Checked dipstick this morning and its overfull still.....lol, apparently u gotta read dipstick like 3-4 times to get accurate reading

Okay, so after reading this I can conclude that

Engine Oil -- Amsoil is the clear winning (20w-50)

Gearbox oil -- > Redline and Subaru Extra-S

Diff Oil- OEM Subaru


What about coolant> although I know this is a "oils" thread, but on d same topic of maintenance.... and even power steering fluid?

I recently bought a subaru..so may want to do a few things on it by wednesday. Engine oil seems fine, but I am unaware as to which oil is being used in the diff and gearbox.. (WRX setup) So may drain and fill fresh.

change everything so you know what is what etc.

i use redline water wetter

^^ I am not a fan of water wetter..i used that on my previous car... and my temperature reading were around the same... I rather just use OEM coolant... right now it has some green coolant, so im doubting that OEM...but i'd change it out anyway soon.

Honda oem coolant works fine as well

A bit late, but anyway, when I had Subbies I used the Royal Purple oil, Subaru stock fluids for diff etc, and AMSoil coolant. Everything worked fine. Tried the AMSoil for a short while, didn't really see the point, but a lot of Subaru people swear by it.

I also saw that demo the Schaffer's people did and the RP was the only one to last with the Schaffers.
Also asked the guy what he used in his own car, including his race car, and his answer was RP until he started selling the Schaffer's.
But anyway, I use the AMSoil now, and it works fine also. Interestingly it made the engine a little quieter compared to the Castrol. Other than that, no diff thus far.