coolcat

This is the best oil for your LS3 engine.

Gearhead Jim

If the OP's question was about viscosity, there are several answers:

To comply with the Owner Manual for warranty coverage, only 5W-30

Best "all around" viscosity, also 5W-30

Warranty coverage for some countries in Europe, 0W-40

Temps well below 0'F and you don't care about warranty, 0W-30

Oil temps above ~250 and don't care about warranty, 0W-40

Generally, 0W-30 gives better protection during startup and short drives

Generally, -30W oil is about right for oil temps ~200 to ~230

Generally, thicker oils gibve better protection only at higher temps.

BTW, Mobil1 0W-40 is thicker than 5W-30 at all temps above something like -20'
The "0W- part is measured at really low temps, something like -35'

fnbrowning

This is your best "Cliff Notes" on Which Oil To Use for the C6 LS3


If you still have questions, YES, go to www.bobistheoilguy.com

BSSN

...and most 0-30 is thicker than 5-30 when both cold and hot. I wish they did away with the X-XX crap on the bottle. Too many people think it means something important. This is why a corvette forum is not an oil forum. You might as well ask the guy at Wal-Mart what he thinks. Go to BITOG. It sure helped me with my oil issues in my LS1. FOllowed their recommendation and cut my oil usage from about 1qt every 2-2500 miles to 1qt ever 4500-5500, depending on how I drove it.

Gearhead Jim

Can you give some links for that?

Certainly, there are some 0W-30 oils that are thicker than some 5W-30.
But within a given brand and "model", I have not seen any specs that indicate what you are saying.

CyberGS

pick whatever brand oil you want and stay 100% synthetic, but a more relevant statistic might be this... I drove my new GS around today in 94-95 deg temps getting lunch, etc and the highest my oil temps got, after running errands 20 minutes at a time, was 185 degrees. If I drive to work, my commute is short enough my oil maybe hits 130 deg on a 95 deg day, starting around that 95 temp.

Read thru that BITOG site and it is a bit interesting, tho' if you read his chapters they actually will not always agree with each other, so that is a bit whacky*, but nonetheless I agree that 0W/20 is the best oil choice for anybody who just daily drives with short commutes, etc.

I am waiting 'til spring to swap the oil after winter cold (will maybe have 2K on the first oil by then, just over 1500 right now, not a DD and will get no winter driving other than clear, warm days) and will have it tested to know what's up with it, but switch to the 0/20 except when racing, which will be a rare event with the Vette since I have a race car to beat on instead.

BTW the 10psi/1000 rpm has been a standard in auto racing since the 60s, I think it was Smokey Yunick that first professed that ratio, but don't quote me on that. *Nonetheless, Bob goes on to say he needs 75psi at 6K for instance, not sure where that math came from, but 75psi at 7500 rpm is a good value. I have set an 80 psi bypass setting on my race car's dry sump setup as I spin to 7500 max, typically shift around 7300 rpm for example. Just a tidbit-o-info.

AirBusPilot

Buy your favorite oil.

Get an oil analysis done at about 3500 miles.

Decide.

BSSN

Sure, we can use Castrol.

http://www.castrol.com/liveassets/bp...syntec_usa.pdf

Please observe that the 0-30 is thicker than the 5-30 and the 10-30.
(look at cSt. This is the number that is relevant, precise, and shows you how thick an oil really is at a given temperature. That big stupid number on the bottle has people running around this forum telling others that oil thickens up as it gets hot because "the little number is the cold number and the big number is the hot number". Again, this is a corvette forum. Go to BITOG if you want to talk to people who know a thing or two about oil.)

Here is a GREAT explanation of what I mean about cSt and "X-XX" ratings. The X-XX ratings have such huge parameters that they are pointless. It would be like if GM sold a 505bhp car and considered 400-600 horsepower "acceptable" parameters. You wouldn't buy without a dyno-test first, lol.
http://www.upmpg.com/tech_articles/motoroil_viscosity/

Most people don't care/aren't capable of understanding cSt numbers and so they just stick with the tried and true. I think anyone who can post on this forum and communicate can understand cSt, personally, but you have to understand that things are written at an 8th grade level in the professional world, and even lower when being presented to large cross-sections of consumers.

This is why I get so bent out of shape when people quote the big numbers on the bottle. They don't mean a darn thing. The range for them is huge, and many other grades eclipse others, etcetera.

I found, as did every other person who reported to have changed from M1 5-30 or 10-30 that the 0-30 GC formula burned 100% OR LESS off between fills with the LS1 engine. I remember when I was on LS1tech.com years ago and Patman was doing UOA's that showed the oil was still doing well at 9K miles+ in his LS1, and everyone who tried it (me included) couldn't say enough good about how their car stopped using oil.

GM has changed things, for sure, but it is still an LS based engine and the technology of low-tension oil-rings, short skirt pistons, and PCV systems that are rather aggressive continues.

Unless the LS3/7 is somehow different from the LS1,2,and 6, the best UOA's I have seen come from 0-30GC. That is not to say that other oils won't "do the job", but that the 0-30GC does very well compared to anything else out there I have seen. LSX engines seem to like a cSt of around 12 when at operating temp. It cuts down on oil usage and seems to protect well.

Go to BITOG and pull up some UOA's for LS1's, 3's, 7's, and whatever else and 0-30 GC. They have a MASSIVE! database.

You will note that if you look at Mobil 1, many UOA's show it shearing into the range of a medium to thick 20 weight by 2-3K miles. Mobil 1 likes to shear. It's not full group IV.

*** Please note, 0-30 Castrol Syntec European Formula is the only Castrol that I am aware of that is Group IV, the rest are group III.

BSSN

Good call, but also realize that many wear-metals are not "stabalized" until sometimes 30K miles or more, so the numbers will continue to decrease from UOA to UOA regardless of the oil used most likely.

AirBusPilot

I just had an oil analysis done at 3700 mi. on the oil, 10.7k on the engine (LS7) and it came back better than universal averages, except for "mildly low viscosity" (which wasn't caused by fuel contamination or coolant). BL stated it wasn't hurting anything.

Castrol Edge 5w30. Based on the "mildly low viscosity" I suspect it's a GRP III oil. On another oil analysis that I had done previously on my LS3, the viscosity was perfect, and this was with 8550 miles on that oil - Amsoil SS 0w30 GRP IV. A third oil analysis done on my civic was fantastic, including TBN, with 13,500 miles on that oil (85k on the engine). Again, Amsoil, in 0w20 GRP IV.

BSSN

Castrol uses group III oil in every case I am aware of except the 0-30 European formula. As far as I know, Mobil 1 does the same thing (They say they don't, but the UOA's tell the tale, and they DID lose a lawsuit against castrol for calling their "synthetic" a "full synthetic", hence their sheared down viscosity numbers as well. Amsoil, 0-30GC, and some of the other grpIV oils are the way to go in my experience with the LSX engines. Any sort of thinning of the oil and it goes right past those low-tension oil rings or mists into the PCV system.

corvet786c

I tried reading BTOG site and hard to understand what exactly he is saying? So u are saying then to use 0-30 from now on. Mobil-1 or amsoil 0-30?

GOLD72

cSt is a term of measurement for kinematic viscosity which is of course relevant to choosing an oil. cSt is an abbreviation for centistokes. Also fluids can also be described in terms of absolute or dynamic viscosity and that term is cP or centipoise. cP and cSt are directly related via specific gravity by the equation cSt=cP/sp gr. Oils can also be specified by SSU (Seconds Saybolt Universal) at a reference temperature like 100degF. My high speed compressors I usually buy run on 150SSU@100F light turbine oil which is also known as ISO Grade 32 which is ~32 cSt. Probably more info than most of us wanted to know.

fnbrowning

Wait a minute B4 you pull the trigger.
While there is some great information in the posts above, your choices are not limited to just European Castrol or Amsoil. Especially the multi-level marketing, over-priced, over-hyped Amsoil!

There are other oils out there that perform better than Mobil1 and provide great wear numbers. Pennzoil Platinum for just one example.

If you read the link on tech_articles/motoroil_viscosity, that has some great info in it to be sure. But notice, Amsoil disingenuously leaves the unwary reader with the idea there are no Group IV (4) PAO based synthetics to compare with Amsoil. Can anyone say "REDLINE?" And Redline is not sold through multi-level marketing, just direct to you at your local speed shop or even Amazon.com


Look, this is not the best place to choose your favorite lubricating oil. BITOG is the place to visit.
Yes, you are going to spend some time sorting through various threads, and, there are no easy answers.
(okay, 1 easy answer. Pour the Mobil1 5w-30 in the sump an fuggetaboutit )
But choosing the superior product for your engine is going to take research. And then do this:

Good Luck!

Gearhead Jim

BSSN-

Thanks for the link, interesting numbers.

The temp/vis chart I have for Mobil1, does not run that way. Mobil1 0W-30 is thinner than Mobil1 5W-30 at all temps below 40'C. That's what people would expect, and is better for low temp starts which are the reason most folks buy a 0W instead of a 5W.

Picking an oil is, as you said, not as simple as looking at the bottle on the shelf. But i think we worry too much about this, the LS- series engines seem to last a very long time on any oil that meets the specs.

BSE1956

whatever you use, change it often and get a magnetic drain plug.

BSSN

But not more than most of us NEED to know. SAE viscosity tell you how fast an oil flows through a little hole and groups them accordingly. Cramming a broad-range of viscosities into one "category". cSt and similar measurements tell you how thick oil is.

It is similar to saying "My car is a 12 second car". You could be talking about a C5 Z06, or a 1998 stock Z28 Camaro. They are both technically "12 second cars" according to some test numbers, but take a guess which one is faster...

cSt is like saying "My car runs 12.2." and "Your car runs 12.9".

World of difference, now!

That is how SAE viscosity compares to cSt, in gradeschool level analogy.

BSSN

I saw Mobil 1's chart. However, 0-30 is thicker than their 10-30 at operating temp, according to their chart. This is why you need to abandon SAE viscosity and go with cSt if you care enough to ask a question like the OP, instead of just "throwing something that meets GM spec" in the crank case.

For most people, throwing something that meets spec in there will work just fine. For the OP--well, they wanted to dig deeper. Digging deeper solved almost all the oil-consumption issues with LS1's back in the day. People began using oils in the 12 cSt @100*C range and the oil stayed in the crank-case.

BSSN

Pennzoil Plainum is a GREAT oil, but is a bit thinner than the "european" formulas. It will provide great engine protection, but the engine may/may not burn it. I know my Infiniti drank a quart of it last oil-change. I switched to 0-30GC to see if it would matter. However, my Infiniti actually pressurizes the valve-cover. I am betting most of the oil made it out through the PCV. I am curious to see if the 0-30GC slows this, any. (No, rings are fine. Compression was 185,185,182.5,185 on dry cylinders. Nissan/Infiniti spec is 179. These 4-cylinder import engines are just wierd like that, I have been told.).

My aversion to "redline" oil is simply because people hear the name alone and get a bad taste in their mouth, from the connotation of racing and whatnot. If your car is under warranty, "Amsoil" or "Pennzoil" or "Castrol" sound a lot better to your service manager. I know that detail is stupid and petty and you can simply lie about it, but I think we can all admit we would rather honestly say "I was running Amsoil/Castrol/Pennzoil/Mobil 1" than "I was running redline" when the valve snapped, as quick as auto manufacturers are to look for a way out of a warranty. Yes, you can take them to court and get it covered, but it will take a minute. Most large companies invest their money, so the longer they retain capital, the more it makes for them, so even if they just stall in paying, they are bettering their position. It's not "I finally won", its "we held out and made an extra $XXX off of the money we spent finally fixing your stuff".

Danno5069

I know what the filler cap says, I want to know if their is a better oil out there ie Castrol and can I change the viscosity. Im in Canada so the car sits in the garage 80% of the year