What Brand/Type Of Synthetic Oil?

[Keaton85]

Just a side note, that the wider the spread between the numbers the quicker the oil will break down. More viscosity modifiers have to be added in order to get the number range. So a 0W-40 would break down faster then a 10W-30. BUT you want the thinest oil you can get for cold starts since this is where most of the wear happens! So when you go buy 10W-30 and there is a 5W-30 right next to it, BUY the 5W!!

I really wish the US stocked more 40 weight like every other country. You go to NZ, Australia, or Europe and you would be hard pressed to find a 30 weight.

[cheesecake]

I run amsoil 5w30 also because i am a dealer

[Crito]

Snipped from a BITOG thread:

Syntec 5w30: 9.7 cSt @ 100°C

EDGE 5w30: 9.8 cSt @ 100°C

Syntec 0w30 (GC): 12.2 cSt @ 100°C

12.5 to 16.29 cSt @ 100°C is a 40 weight, so GC is, in fact, about as thick as a 30 weight gets. The first number (winter grade) actually represent about the same viscosity -- the min needed to crank and pump -- but at different/lower temps.

[Keep Calm Chive On]

thats why i love GC because although it doesnt hit dead nuts on 40 weight it is very close, so it has very good cold viscosity as well as heat protection

[VolvoRine]

So let me ask you this can you swap from mobil 10w-40 high mileage to GC 0w-30 right away without any problems?

Does GC works with any mileage on the car without any adverse effect at a short or long term?

Can that be safe and beneficial to my car at the same time??

[Crito]

So let me ask you this can you swap from mobil 10w-40 high mileage to GC 0w-30 right away without any problems?

Does GC works with any mileage on the car without any adverse effect at a short or long term?

Can that be safe and beneficial to my car at the same time??

If your owner's manual says use a 40 weight I'd use a 40 weight. But for what it's worth, when I switched from dino to Mobile 1 10W-30 High Mileage on my (then) 125,000 mile S80 I sprung a minor RMS leak. At 140,000 miles I switched to Castrol 0W-30 and the leak stopped! I'm also burning virtually zero oil now. I think Mobile 1 cleaned sludge out better -- you could look up VOAs for detergent additives to verify -- but the Castrol 0W really does seem to work best in my S80 for some reason. The motor even sounds a little quieter... I boolshiat you not. ;)

[Keep Calm Chive On]

i didnt use 10w-40. I started with 10w-30 castrol syntec blend the semi syn. I switched to 0w30 fully syn G.C. Never had leak issues before still dont now. I lied my turbo line drips a drop now an then but i have the seal just cant get the thing off. People tend to mask leaks with thicker oils only because they are less viscous so they cant make it through minor cracks or leaks. If you have a large leak regardless of what oil youll know. Minor ones are jsut masked with thicker oils.

i think exact calc was something that G.C. is 0w-37/38 ish or some crap but they measure in 10's. It has like 95% of the properties of a 40 weight oil. The reason i switched was because my car is getitn up in miles (500+ a week) so i wanted to get it the best it can have. I did a ton of reading on BITOG and came to the conclusion that G.C was what i wanted. Nothin against mobile 1 but most of their hype is because of extreme advertising. Money could be spent else where haha but regardless amsoil is overprices heavly modified class III dino oil thats so adjusted its "synthetic" same with most other oils. I wont say that G.C. isnt the same way but from what i heard it was the only legitski out there at the time. Obviously times have changed & people just want more $$$ for less investment sooo for all i know im puttin whale pee & cat poop in my car now. But because ive never had issues & enjoy knowing im happy... I still use it. A LOT

basically find out what works for you & what schedule is best for you. People call me crazy because of how often i change it & price i pay etc etc but it doesnt upset me so im okay with it (i will admit im going to start going 1k more a change & see how i like it.

Rotella Syn 5w40 - my buddys rigged up WRX

M1 0w-40 - my pops benz

crap - my moms jeep

mobile clean 5k - bros Ford F150

G.C. - My T5

Syntec Blend - my T5 (past)

OEM filter only, never FRAM! EVER. they filter so good... they dont flow & it just goes through over flow aka never filters at all...

[ozzimark]

Just a side note, that the wider the spread between the numbers the quicker the oil will break down.

Very true for group IIIs and semi-synth, but not so much for group IV oils.

And it's not the oil itself that is breaking down that is the problem in what you're referring to, it's mostly the viscosity modifiers.

[VTT5]

Just a side note, that the wider the spread between the numbers the quicker the oil will break down. More viscosity modifiers have to be added in order to get the number range. So a 0W-40 would break down faster then a 10W-30. BUT you want the thinest oil you can get for cold starts since this is where most of the wear happens! So when you go buy 10W-30 and there is a 5W-30 right next to it, BUY the 5W!!

I really wish the US stocked more 40 weight like every other country. You go to NZ, Australia, or Europe and you would be hard pressed to find a 30 weight.

I was with you until the second paragraph, which confuses me. Let's see if I get this right:

1) wider cold/hot spread = bad (quicker additive breakdown)

2) lower cold weight = good (less wear at startup)

3) You personally want access to more oils with higher hot viscosity (and thus a greater spread from your low cold viscosity, apparently in contrast to point #1). I must be missing something, like you race your car so you're worried about high temp breakdown, right?

[Keaton85]

I was with you until the second paragraph, which confuses me. Let's see if I get this right:

1) wider cold/hot spread = bad (quicker additive breakdown)

2) lower cold weight = good (less wear at startup)

3) You personally want access to more oils with higher hot viscosity (and thus a greater spread from your low cold viscosity, apparently in contrast to point #1). I must be missing something, like you race your car so you're worried about high temp breakdown, right?

1: Correct

2: Correct

3: I would personally be fine with a true synthetic 5W/10W-40 oil if that was easy to get. Even a group-III hydrocracked would be fine at 10W-40 though in my opinion. The 40 weight for me is yes kinda about protection but mostly about drive train noise. haha Also because I want what I cant easily have!

It's a lot of opinion really, I have done a lot of research and have a handful of car's to maintain so it comes down to many different factors for me.

Sidenote: I just did an oil change on my T5M from a 40weight group-IV to a 30weight group-III hydrocracked and I believe I'm getting slight pinging under WOT over 5K RPMs. I'm hoping it's just something with suspention travel but non the less it's not a sound you want to hear on a different oil :o

[Keep Calm Chive On]

sooooo is me running 0w-30 G.C. good? its close to a 40w on the hot... & lovely cold. but is it legitski Class IV? cause thats what i heard. zie germans fail me? hope not cause my tattoo isnt erasable :ph34r:

[Keaton85]

German castrol? Yes the last time I checked it was a group-IV

Where are you getting it from?

[Hoosier Daddy]

who did you check with? castrol (bp) isn't saying. in fact, their msds and product info sheets give about the least amount of info of any major oil producer out there. it gave me the impression that they aren't exactly forthcoming. just because it says made in germany doesn't make it grp IV. it also says not for sale outside the us, where grp III is considered synthetic. ergo, can't sell this "synthetic" oil anywhere but us because it's only considered synth in the.... us!

[Keep Calm Chive On]

I buy 0w30 & there is "made in germany" and "made in US" I scoop up the made in Germany when available. I have a friend of a local auto store get it for me. He usually doesnt carry it (and its always a bitch to find) but i let him know a week prior to me changing my oil & he gets me a case + 1 (7 total)