angel71rs

Actually, the one reason I would hesitate to buy wally oil is that I might end up buying stock supplied by Mobil.

From what I've read on the boards/UOAs about M1 30 weight oil possibly being too thin for LS1 motors, I'll stick to the M1 T&SUV 5w 40 I've been using or GC/European Formula if I can get hold of it.

bene

iTrader: (16)

I second to this question. And where can I get this GC stuff you all talk about. I just made a mistake of putting synthetic blend Quacker State. I'm having that sewing machine noise.

Also, where can I get this Amsoil?

Mike02Z

iTrader: (13)

GC stands for German made Castrol 0W-30. In independent tests it has shown to be one of the best engine oils for the LS1. It is a fully synthetic oil and it is only available at some Autozones. It must say "Made in Germany" on the back and the only Castrol that says that is the 0W-30 grade. So, it must be 0W-30 AND say "Made in Germany" on the back. Anything else is not the stuff that we are talking about. Most autozones have stopped carrying it in their smaller stores as it did not sell very well. You might still be able to find it in some smaller stores that have not sold out yet. The larger Autozones with more shelf space will be keeping it. Autozone is the only place to find this as far as I know.

Amsoil can be found online at a number of LARGE autopart outlets. None of which are sponsors here so I cannot mention the names. Some sponsors may carry it but I do not know which ones. Redline is another good oil for the LS1 as is the Royal Purple Racing 41 formula. The 5W-30 Royal Purple is too thin for the LS1 from the tests I've seen. The resident oil expert here is Patman and he and some buddies conducted a good many independant oil tests. bobistheoilguy.com is where you can read the tests.

Couchman86

iTrader: (5)

+1

tirefryer

I have used both GC and the Amsoil 5W40. The Amsoil 5W40 quieted the piston slap considerably over the GC 0W30, and my oil pressure is slightly higher across all temp ranges with the Amsoil 5W40. I do not have any analysis to compare wear between the two, but the Amsoil definitly quieted the motor down.

WhiteStripes

iTrader: (1)

Although I've bought out my local Autozones, anyone else know of chains that carry the German formy?

bad6as

iTrader: (17)

ive used them all
m1 5 30
castrol syntech 5 30
amsoil 5 40
amsoil 5 30
penzoil platimum 5 40
penzoil dino 5 30

the castrol syntech 5 30 sucked i drained that after 600mi
m1 530 i used a couple times, when the car was at 210* the oil psi was below 40psi
the penzoil dino was only because i was trying to get rocker arm needel bearing out of the pan oil psi was lower then 40 at 210*
i have that platimum 5 40 in it now less then 300mi its ok better in the psi then the others and a lil quieter then the m1 530 at 210* its at 40 psi
the amsoil 530 was quieter then teh others and about teh same psi as teh platimum
the ams oil 5 40 imo was the best ive used oil psi all ways over 40psi no matter what the temp was and it was dead quiet.

i got the the m1 5w30, castrol 5w30, platinum 5w40 all for free (working at jiffylube)

i bought the others
and ill try the gc next go around
and i stocked up on some m1 0w40 ill try that too

my vote is for the amsoil 5w40 due to less noise, and a higher oil psi

Joey7489

iTrader: (21)

what about good old 5w30 royal purple?

bad6as

iTrader: (17)

imo the way rp frees up hp is because its so thin. and thats no good

G&HRacing

Straight 30W Valvoline Racing Oil for me.

98hardtopZ

iTrader: (7)

gc ow30

FL01SS

I went with the Amsoil 5-40 and couldn't be happier! There's pretty much NO lifter noise anymore and I've got 10 to 15 more lbs of pressure at idle.

chevygirl

iTrader: (69)

Is the higher pressure a good thing? I know you don't want low pressure but is 10-15 too much? I am thinking about 10-40 castrol syntec. They also make a 5-40 european formula now.

00454sscamaro

i run rp 10w 30 works great for me i switched to royal purple for the exact reasons you mentioned , i also like the gc and amsiol.


mobil 1 just shears too easy(even extended performance -wich i tried out before the rp but drained due to it loosing oil pressure at less then 2 k miles on the oil), looses oil pressure and needs to be added to too often. the rp $ was worth it to me. no noise anymore, havent lost any oil or oil pressure like i did with the m1. next change i might go to amsoil or gc just to see wich of the three i like best , amsoil is the only one i havent tried in my car yet though(hafto order it online to get any). i havent used gc in a long time (harder to find then m1) but the rp is a vast improvement in noise over the m1 +availible at local speed shop (and i didnt switch for the claimed 8 hp)

LittleSlow1

I just switched from Penzoil 10-30 to GC 0w-30. I am also using the K+N 2006 deep oil filter. The "sewing machine" noise is a lot quiter, or not even there. Before on cold start ups you could definatley hear the LS1 disease (piston slap), but now you really have to listen for it, and know what your listening for. The engine seems to run smoother. Once the engine is up to temp I have about 35 psi of oil press in gear @ idle.

I'm not sure but the car may have picked up .5 mph on my ET slips, but that was a combination of the oil change and using UnLeaded Race gas compare to V-Power and the Penzoil.

The only thing that bothered me a little bit is when the midwest had its heat wave up here; my oil pressure went down to about 20 psi in gear @ idle, but as soon as i would crack the throttle it would go up. This happened after about a hour of driving.

Now that the weather is somewhat normal now my oil pressure is back to normal. I'm glad I made the switch, but excessively hot weather makes me a little nervous with the 0W-30.

wolfy

iTrader: (1)

thats why i havent tried the GC yet. down here in tx it gets really hot and my car is a daily that sits outside all day. ive yet to have a problem with the m1 10-30 so ive been kinda lazy about switching. but i havent had the "sewing machine noise" or had any consumption problems. and actually, it seems like my oil press is a good bit higher than any other ls1 ive seen. i think when i switch im going to amsoil 5-40...my $.02

dre2013

iTrader: (7)

i run amsoil...ive heard very good things about it, and it also helps that my roommates dad is a dealer, so i get player prices lol