Its almost time for my first oil change in my WRX and i was wondering if I should use synthetic motor oil or just stick with regular motor oil, or go for a synthetic blend?
What do you guys use in your cars?
Thanks,
Zoeb

rumor is that u should keep dino oil for a few thousand miles to break in the engine. ... but seems everyone ditch and we syn at 1000 miles.

all preference, either way u will be ok..

i went syn at 3000 miles. oh... Mobil 1 10 30

I was a bit more conservative and only went synthetic after ~7500 miles...Mobil 1 5W30

The dealerships in my area are promoting synthetic big time...especially for the WRX. I guess they do make more money if people use synthetic oil... :P

I waited till 3000 miles to change mine to synthetic. I ended up using 15w 50 tri syn from mobile one. I had about 15000 mile on the engine when i had to tear it apart. When i opend it up the cylander walls and everything looked brand new. Keep in mind that most of the 15000 miles were spent at auto-x road racing and street racing running nitrous. Just my 2 cents.

suby_speed quote:

I waited till 3000 miles to change mine to synthetic. I ended up using 15w 50 tri syn from mobile one. I had about 15000 mile on the engine when i had to tear it apart. When i opend it up the cylander walls and everything looked brand new. Keep in mind that most of the 15000 miles were spent at auto-x road racing and street racing running nitrous. Just my 2 cents.

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Why 15w50 and not 5w30 or 10w30? That oil is so heavy. And what does the tri mean in try syn of your above quote?

I switched over to full synthetic after 3k. Not much difference from what i can tell. From what i read at the other site though is that synthetic resists coking more than dino oil. hope that helps.

oh yeah, i'm running mobil 1 5W-30. Costco has it for like $26 for 6 qts. Cheapest place i've found.

changed to full synthetic as well @ ~ 3000. running amsoil 5w-30 7500 mile synthetic. i think it's 5 or 6 bucks a quart;)

I switched to Mobil 1 10-30W synthetic at 20,000 miles :)

i use 5-30W Mobil 1 for winter time :)

Andy...

Castrol 5w50 Syntec after 3000miles here... been running fine!

after 10k miles, i switched to Mobil 1: 5-30W.

i just switched to mobil 1 sythetic at around 12500. i didn't feel too much of a dramatic difference though.

peter

Went synth @ 7700 miles. Mobile 1 10W-30. Seems to be working as good as Dino Oil, can't really tell the difference. I'll check back in 50k miles. :p

I changed to mobil one at 1k 10/30 summer and 5/30 winter

Cheers,
Jim

I went to Mobil 1 10w 30 after 6,000 miles.

I have been using Mobil 1 synthetic since day one off the new motor 9000 glitch free miles and 20,000 on the car. No prob.

Originally posted by STI RDY
I was a bit more conservative and only went synthetic after ~7500 miles...Mobil 1 5W30

Same here.

How often are you guys changing your oils with Synth in it? 7500? 3500? I'm not understanding some posts...

I still change my oil at the 3,000 mark.

Some people say you can use an extended interval with synth. With my car whenever I get close to the 3,000 mark the engine tick gets louder until I change the oil.

when i was a frequent visitor to Miata.net (great place!) I heard that most modern engines fully break in after about 30k mi (i'd assume under normal driving). In magazines, you can find Long Term reviews that show better performance numbers after 25k~30k mi. I'm referring mostly to Japanese cars.
So, there's my reason for waiting til i got 30k mi to switch. (Mobil1, of course:) )

i'm using 10-30w (SoCal), 3500-4500 mi. interval

valvoline 10-30. change oil every 2500-3000

I change mine every 3500 or three months, whichever comes first.

Mobil 10w30 at 7500 miles, I change every 5000. I do lots of highway driving

So the people who do use synthetic, what positive changes did you actually NOTICE....did you notice a difference at all?
What kind of difference did you see?
Thanks again...i appreciate all the responses.
-Zoeb

I would defenatly not use synthetic. Especially in the tranny, unless you want it to blow.

The running in period should be on a mineral oil to allow the bore particularly to wear in. I recon on an oil change during the first 1,000mls(after rebuild) and again at 3-4,000 intervals. So aim to be fully synthetic at 4-5k mls.
I cannot comment on the version 7 engines but on my STi 6 I run Motul 15W-50. If it is good enough for WRC cars it might do for my odd track and drag day too.
In Europe 5-30 oils are considered too thin even in Winter.
This car has full instrumentation and monitoring pressure and temperatures of several "recommended" oils has been interesting and has re-enforced my belief that thin oils can lead to problems, particularly if you run on track where very high temps are reached.
Editted to say that no improved running could be detected, no improved fuel consumption but improved an maintained oil pressures are evident right up to oil change time.

Originally posted by 02BlackWRX
So the people who do use synthetic, what positive changes did you actually NOTICE....did you notice a difference at all?
What kind of difference did you see?
Thanks again...i appreciate all the responses.
-Zoeb
before with dino avg 23.0mpg. with mobil1 25mpg. on the way to El Mirage last wkend avg'd 26.8mpg fwy driving.

i would like to think it's due to Mobil1 (at least that'll justify the extra cost of Mobil1...)

Originally posted by John #555
before with dino avg 23.0mpg. with mobil1 25mpg. on the way to El Mirage last wkend avg'd 26.8mpg fwy driving.

i would like to think it's due to Mobil1 (at least that'll justify the extra cost of Mobil1...)

you know...now that i think about it. i think my mileage improved too when i switched to synth.

~7k or so, switched to mobil 1 5w30

speed safely

Brian

22K switched to red line 10 40

I switched late; Mobil 1 5w-30 @ ~20K. That is when I decided to go to TurboXS Stage 4. There is no noticable difference, but didn't expect any. Synthetics don't break down like dinos, but still change about every 3K to 4K miles

On the forums "formerly know as i-club" :) some changed to synthetics at 1st oil change & a few as soon as they took delivery. There are enough of these cars running around now that they surely would have complained about problems by now. Ppl complain about everythingelse in the forums at the drop of a hat.

Mobil1 can't go wrong!

I switched to Mobil1 at approx 3,000 miles. I don't think that you would be able to notice a performance benefit. I view it more as a reliability benefit. The oil should degrade less over time. I still change the oil every 3,000 miles.

Originally posted by Lobster Man
I would defenatly not use synthetic. Especially in the tranny, unless you want it to blow.

Lobsterman, care to elaborate on a rather sweeping statement!

Why wouldn't you use Synthetic oils? And why not especially in the tranny?

I've run Castrol Syntrans 75w90 in my S4, and I use Eaton Fuller (Trucking products) 75w90 synthetic gear oil in my STi RA gearbox for over a 1 1/2 year. I've used and abused the gearbox over that period.

I opened it this summer to change the pilot shaft oil seal and looked the gears over and they looked brand new. The synchros showed a little wear, which is normal.

Both oils are API GL4 or 5 certified, so they fit the Subaru application chart...

I'm just curious why you say using synthetic products will blow up trannies.

i stopped using oil. i found the human urine works the best. smells great too when its warm.:)

Ahh yes, urine... Seemed to work for Patrick Swayze's Radiator in Red Dawn...

Originally posted by evilwrx
Mobil 10w30 at 7500 miles, I change every 5000. I do lots of highway driving

me too. about 85-90% of my driving is highway. i can't remember what the user manual says but i thought it said around 7000 miles? anyway i change it ~5000 or 4 months. i run the amsoil 7500 mile oil, figured i should be ok.

what is with mobil-1, why is everybody running it?

Originally posted by scooby5
I'm just curious why you say using synthetic products will blow up trannies.

I've read synthetic in tranny provides too much for the syncros to work - not enough friction for syncros...

John,

That's a good point. Some gear oil have friction modifiers, some don't. I think Redline is one of the brand that does that.

I haven't had a problem with the Syntrans (I think it's not called Syntec gear oil) or Eaton Fuller with my synchros.


I figure though, as long as they meet the API guidelines and the viscosity's there, then it should work. Some people might have different experiences.. anyone else using synthetic gear oil?

Originally posted by scooby5
Some gear oil have friction modifiers, some don't. I think Redline is one of the brand that does that.
Should we apply this to viscous LSD's also? wait, what type of LSD do WRX have? viscous or torsen?

Viscous centrediffs are incased and do not use the tranny gear oil, so that's not really applicable.

The rear LSDs would matter depending on the type. I have a SureTrac one and it seems to work fine.

Originally posted by John #555
I've read synthetic in tranny provides too much for the syncros to work - not enough friction for syncros...

Mine works fine.

Originally posted by Mach5WRX
Mine works fine.
could you let us know which youre using so we'll know what to use?

Originally posted by John #555
could you let us know which youre using so we'll know what to use?

I would also like to know what type of sythetic your using in your tranny Mach5?

A lot of the guys here in hawaii use Moblie 1 full synthetic Trans fluid.

-scu

FWIW ... the cheapest place I have found to buy Mobil 1 is Walmart. A case averages out to about 4.26/qt.

I started using mobil 1 at 20,000mi. I felt that the motor was really starting to break in around 16-18,000mi.

I change my synth oil around 4K mi.

5W-30 mobil 1 synthedic for my first oil change @ 3500 miles. On the second I went to 10W-30 and have oil changes every 3 to 3.5k miles.

You guys aughta try AMSOIL

it is better for the turbo. it lubes the ballbearings beter and handals heat beter.

15W-60 Motul, tropical climate 365 days a year. A bit overkill I think, especially since I haven't done any track event using that oil.

Next service I'm putting 15W-50 Motul.

Interval about every 4,500 - 6,000 miles.

I personally don't like Mobil 1 5W-50. I read that additives are added in order to achieve broader temp range, hence basically you get "less oil per litre" compared to others. In addition I had a not-so-pleasant experience while using that particular Mobil 1 oil.

But I guess you guys have no choice because of the four seasons.

I use mobil-1 10w30. I have been running it since 1000 miles. I buy it at walmart in the 5qt jug for $17.88 other wise it is $4.77 a qt.

I use mobil 5-30 since 2300

mobil 1 5w-30 since ~3,500

Originally posted by TB RACING
You guys aughta try AMSOIL

looks like i'm the minority in this thread!


for you mobil 1 guys, if you have Target department stores around where you live, i saw it there a couple of days ago and they are selling it for like $4.09 a quart

I just started using royal purple 5w30 and it has been a few months and it still looks new. i bought it for 5.49 a qt.

Geez page 4! I think everybody uses Synthetic .. I've been using Mobil1 5w30 for about 25k miles. This thread reminds me; Tomorrow is the day I change my oil. joy
Paul

Mobil one used here as well.

Originally posted by PaulRex
Tomorrow is the day I change my oil. joy
Paul
isnt it? i like the fact that i dont need to raise my car to do oil change :D

Amsoil 5W30 Since 1500 miles......just like my last three cars...never had one problem.....