ta420nk

I'm about to install some hooker super comp lt headers, ngktr55's, msd wires, and a oil change and was wondering.. What oil works best in ls1's? I've been using mobil1 5w20 syn with k&n filter for a couple years now.. Is 5w20 to thin?? Sugestions plz.

Thanks

Arc00TA

iTrader: (17)

http://www.bobistheoilguy.com/cms/

Read and learn. I use GC 0w30 personally.

ta420nk

Wow arc00ta that hurt my brain.. Heh .. Looks like I'm right on with my 5w20 thanks!

Higgs Boson

iTrader: (3)

I run Shell Rotella T6 5w40 in my 408 but it's not a stock LS motor at all.

SOMbitch

iTrader: (8)

Your owners manuel says 5w30 or 10w-30...... might wanna try reading it. If you have a built motor with larger than stock clearances or use it in severe conditions some run as thick as 15w50 with success.... I ran 0w-30 GC when I was stock and run 5w-40 or 5w-50 in this motor depending on the season.....

NoGamesLS1

iTrader: (16)

GC 0-30 in a stoker

02_Z28_G

iTrader: (5)

i use 10-w40 in the summer and 10-w30 in the winter. but i live in texas so our summers can be pretty brutal.

where exactly are you located/how many miles are on the motor?

disc0monkey

iTrader: (10)

anything with a hot rating 12-13.5.

I use 0w-40 MB1. thins out to a high 12 quickly.
GC 0w-30 falls in this spec too.

5w-30 MB1 burns away a lot in my car. Pennz ultra 5w-30 doesn't burn at all, and is MUCH quieter than 5w-30MB1 even though its rated the same hot viscosity.

I couldn't imagine running that 5w-20.

BrdOPry

iTrader: (1)

Wow, for getting a 34 on my act this BLEW MY MIND...went sailing over my head! haha
Im still running stock recommended for my V6 but after the cam/heads/intake/header swap in may that will be sure to change!!

Carter01

iTrader: (11)

0w40 Mobil 1 for 3 years now.

HAZ-Matt

iTrader: (8)

Interesting read.

I haven't really deviated from 5W30... 5W20 seems like an interesting choice too. I wonder though if you might as well go 0w20. There hasn't been quite a huge proliferation of 0W-whatever across a lot of brands yet, however 0W20 is speced in a lot of the newer motors from Ford, Toyota, Honda, etc. If the above article is right, practically everyone would benefit from a 0W at startup, unless you lived somewhere where ambient was like 200F.

It definitely is going to depend on the driving style since a commuter is not going to see hot oil temps the same as a pure racecar

sscamaroburn02

iTrader: (14)

I used to run 5w-30 but after H/C/I swap I now run 10w-40 plus I'm in Houston and summers are HOT!! I've seen guys also put a couple quarts of 20-50 in with their 10w-40 for stroker motors.

reeperz28

iTrader: (1)

5w 30 royal purple great stuff

disc0monkey

iTrader: (10)

how does that article give you that insight

its been verified by every reputable member and sponsor on this site that an LS1 built by GM likes a thick 30(close to a 40). why go to a 20 is beyond me.

LS6427

iTrader: (2)

150,000 miles later on my 427ci....and regular cheap non-synthetic Castrol GTX 20w50 is doing perfectly.

.

joecar

0w40.

HAZ-Matt

iTrader: (8)

Fuel economy

But in seriousness if he is doing 99% driving on the street then he might not see oil temps requiring 30 weight.

I am not claiming to be a a GM engineer, but I do not really know why people like going above 30 especially on cars that are mostly driven on the street. From what I have seen, most of the people that switch to the higher weights do so because they get comfort from seeing high oil pressures, or they did so because they wanted to stop a leak. Just like with a whole host of other mods or preferences, there is a lack of scientific testing... I understand that many people have run 40 weight oils, and I can understand some rationale for a mostly track car, but even so it would seem that for the street that is too high (unless it is a thin 40). As far as going serious weight for racing, it seems that a better alternative would be to keep oil temperatures in a reasonable range with better oil cooling and use a lighter weight like 30 or light 40 instead of 50 to promote better flow. There is a lot of conjecture on this subject instead of great data that I know about, but if there is something solid please point me to it because I would honestly like to read it. As far as ambient temps, I live in Houston too and while it is hotter than a lot of places, ambient is still nowhere near coolant temp or oil temp so I don't see how it is really relevant. The article off bobistheoilguy makes that point as well. The most ambient should have to do with oil spec is your cold spec anyway...

Good post above, too, noting to look at the actual ratings since these do vary, although I would like to know where the numbers come from. It has been a very long time since I looked in the owner's manual FWIW Pennz Platinum 5W-30 is more like other brands 0W-30's and AFAIK Ultra is similar with just different additive package and the better flow when cold and at startup may be the difference in noise between it and the MB1. I have mostly used the Pennzoil Platinum in my car and have been happy with it compared to other oils which is why I keep buying it.

edit: I just quoted the one post, but I guess I comment on various posts by several people... hope confusion is avoided.

ta420nk

I live in Michigan .. Car is 02 z28 42373 miles with all your basic bolt ons .. The bobistheoilguy states that "thinner" oil accually flows better providing better heat transfer to the oil.. Because that's part of it's job also.. Sombitch maybe you should read that sites little test. He's suposted to b the oil guru... According to his scale I'm right in the sweet spot.. And according to him you're not. Just sayin

HAZ-Matt

iTrader: (8)

Just curious, is that the weight you have already been running? If so I imagine your oil pressure has been decent at idle and under load... What brand have you been running? Redline 5W-20 as an example is about the same spec as most guy's 5W-30... I think on average 20 and 30 across the board are only like 5% different at and above operating temp, with 20 and 40 only really being 10% different (not double like you would imagine from the numbers). At low temp obviously that is not true.

Ah well, at least for the time being I am still going with 5W-30 Pennzoil Platinum which is more or less like 0W-30 synthetic as far as temp v viscosity goes.

disc0monkey

iTrader: (10)

in all the data I have compiled, 5w-30 ultra/premium has a 10.3 @100*C. this has similar values to the 5w-30 MB1 than has been deemed too thin. Now being a fan of the pennzoil utlra/premium, perhaps this oil does not thin out as quickly as the MB1 5w30. now these values from the manufacturers can be complete BS but it is what it is. GC 0w-30 is in the 12s. this would be comparable to ultra 5W-40 which is the "ferrari" pennzoil. good luck finding that oil though. i dont care much for the difference in oil pressures, but i do like the lack of piston slap and sewing machine sound from thicker 30/thin 40s.

fwiw after spirited summer driving the oil pressure does drop considerably compared to "normal" driving. this tells me this already thin 30 is thinning out to **** water and the lifter clacking relatively gets louder. at what point do you see the lifters start bleeding to show drops in HP?