rjn

What are you LS1/6 guys running for oil at the track?

I'm planning on M1 15w50...How about you?

Rob
2001 Z06

Morpheus

Rob:

Prior to installing an accusump, I used Mobil 1 15w because the thicker oil helps maintain proper oil pressure during hard cornering. After installing all the DRM stuff, I used Mobil 1 10w30 just have some more protection. This season I will be using Royal Purple Racing 21 (5w30).

That's my opinion of what to use.

Gearhead Jim

Rob-
If your car is still under warranty and not modded to the extent it looks like a track car, consider staying with Mobil 1 10W-30. If something breaks and you tow it home, you might well get it fixed free. If the engine gets trashed and you have heavy oil in it, that is a legal excuse for them to deny warranty, and it also screams "TRACK CAR" to anyone who knows the real world. Blackstone labs says that much of their oil analysis work is for car makers who suspect that a damaged engine has not had specified oil and change intervals, so GM just might check what weight oil you were running.
Bragg-Smith uses Mobil 1 5W-30 in their ZO6 cars, keeps the oil 1 qt over full, and was doing great last year.

rjn

Thanks for the feedback

It really riles me to run thinner oil for solely for warranty liability reasons, as I've always used 15-50 at the track (previous car, BMW). Considering the oil temperatures these LS6s generate at the track, seems like it would be even more appropriate for the C5.

Has anyone actually been denied a claim on this basis? I've got 3 seasons of warranty left. Hate to toss the warranty, but am also concerned about long term durability (planning to keep the car beyond the warranty)

Thanks again

Gearhead Jim

It IS annoying to do things based on warranty considerations, but I don't know of any way to avoid it sometimes. The fact that the Bragg-Smith school has been doing OK even with the 5W-30 is encouraging. My suspicion is that most of the oil problems in the LS1/LS6 engines are from uncovering the oil pickup and having NO oil pressure, rather than low pressure due to hot oil. But I can't prove that.
I installed a BeCool radiator which keeps my water temp about 20' cooler than the stock radiator would, and the oil about 10' cooler. You might consider doing that, although it is rather expensive (~$600 plus labor) and is a real mod to the car, not something you can drain and replace like oil. "I put it in because the water temp was running rather high on my trip in Florida."

rbeckham

The main risk is oil starvation from the pickup sucking air on corners. So always overfill.

Your owner's manual tells you what oil you can use. I didn't check it lately, but I'm pretty sure it says that in normal ambient temp. ranges 10w30 or 10w40 is fine. Also, any quality sythetic oil is fine, such as Castrol Syntec. They can't void your warrenty for going by the book.

tjea

Ive played with oil viscosity in my old C4 couple. I tried 20/40 Redline at some track events after running 10/30. I noticed that the oil temp went up with the 20/50. After speaking to Redline confirming, if your eng is reasonably fresh 10/30 should provide the protection you need. The higher viscosity will hold more heat.
In my Z06 I have continued to run the Redline 10/30 with an extra qt on the track.

Gary2KC5

I know how you feel. My previous car (Porsche) comes from the factory with M1 15-50. But GM engineered the LS1 for 5/10-30 with small oil journals.

I had an oil pump/consumption problen that produced burnt oil. Before the dealer rebuilt the engine they ask for proof I had changed the oil. (they actually just ask for filter reciepts). They never ask whay viscosity the oil was just if it was M1 (and stupid questions like if I had put STP in the oil :lol: )

I recommend using only 5/10-30 M1, or a an equivelant.

rbeckham

Use 10-40 Mobil 1, which satisfies the GM requirements per the owners manual, and should satisfy the requirements of any modified engine for track use. I really don't understand what the issue is here. You are much better off worrying about the lubing and cooling of your trans and rear in competition environments.

Gearhead Jim

That's a minor typo (Mobil 1 not available in 10W-40)
The Owner's Manual for my 2001 says 5W-30 is acceptable at any temperature, 10W-30 is OK down to 0'F
As previously mentioned, I run the 5W when outside temps are below freezing, 10W when temps are above freezing.
Have fun on the track this season!

rbeckham

OK - I was finally forced to pull out my owners manual. First of all, GM says engine oil must meet "GM4718M" standards, whatever that is - I assume it means Mobil 1, but doesn't mean that Mobil 1 is better than other premium synthetic oils. Secondly, it says if ambient temps are below 0 degrees F, use 5w-30. Over 0 degrees F, 10w-30 is OK. The manual specifically cautions against using SAE 20w-50.

Logic may not be the prevailing thing here, but my own logic tells me that since my Corvette has never seen 0 degrees F in its life in the February of its coldest year, 10w-30 is the LIGHTEST oil I would use under even the mildest of uses.

Since 10w-30 and 10w-40 at least theoretically have the same low temp flow and viscosity characteristics, my logic further tells me that 10w-40 would probably be better than 10w-30 for heavy duty use at a hundred or more degrees higher temps than light use at the 0 degrees OKd for 10w-30 (mind you, this is just logic, no more than that - I am not saying that GM would agree).

My BMW owners manual (sorry about that) says that up to minus 10 degrees F one should use 5w-30, over minus 10, 15w-40 is preferred. It further speciifies only API "SG" rating for the oil. But I happen to know that what my BMW dealer uses is 10w-40 Castrol Syntec for dealer changes. This is what BMW euphemistically refers to as "special engine oil."

Mobil 1 at least used to be available in 10w-40, which I had always used in my 1993 C4 coupe. However, it may no longer be, as I had to buy the Syntec last time I went looking for this grade for my C5. I don't know whether Syntec has a "GM4718M" rating or not, but if it is good enough for my BMW it is good enough for my Corvette, and preferable as far as I am concerned at high ambient and operating temperatures under heavy duty use.

I don't know if this adds anything to the collective wisdom on this matter, but you might want to factor it into your considerations in deciding which grade oil to use. I can't imagine in my wildest dreams GM denying a warranty claim because it takes the time and trouble to to analyze the oil in the sump and declare that it was 10w-40 instead of 10w-30. It would make more sense to remove your cage, race tires, class numbers and nitrous bottle before making your warrantly claim than to change your oil. Just my 2 cents.

Jim 47

rbeckham:

GM 4718M is a performance specification similar to " SAE SG" but more stringent. The API viscosity grades of 5W-30 and 10W-30 of both Mobil I and Castrol Syntec meet the GM 4718M specification. All you hjave to do is pick up the can and read the specs that the oil meets. The higher viscosity grades (15W-50) do not meet the GM4718M spec., I guess because of the higher viscosity.

On the track I usually mix Mobil I or Syntec 5W-30 and 15W-50 in equal amounts, which gives me a very wide viscosity range in the crankcase. I feel that this will provide both low and hight temp protection, and a little overfill assures no oil starvation in the corners. I'm not sure that this is the best way to do it, but it works for me. I think that if your oil pressure is above 35-40 psi during very hot oil conditions and 2000+ RPM, you'll be OK. Just keep a close eye on those pressures and temperatures. :D

mnasrallah

After asking lots of questions aroung the SCCA guys, most recommend 10W40 or Redline SAE 30 or 40 Racing Oil for track, then change out for street. http://www.redlineoil.com/products.htm

Also, here is a good test on redline from c5-corvette http://www.c5-corvette.com/redline.htm

blackshark

We Mobil 1 5W30 all season with no issues. Good tp 305F at least (adding a cooler this season). Always ran 1 QT. over.

Gearhead Jim

I have a copy of the temperature-viscosity graphs for all weights of Mobil1. The graphs are fax copies, a little hard to read, but these numbers should be pretty accureate:

When you are running hard: 15W-50 has the same viscosity at 280', as 10W-30 at 220'. That should be great.

When you are just getting onto the track: 15W-50 has the same viscosity at 180', as 10W-30 at 140'. Just a little thick, I'd say

When you first crank the engine on that chilly morning: 15W-50 has the same viscosity at 40', as 10W-30 at 20'

At 300', 0w-30, 5W-30, and 10W-30 are virtually identical. For hard use, the 10W-30 is preferred only because it should be more resistant to some types of chemical breakdown (especially if the temps get even higher).

For us wintertime daily drivers, 0W-30 is virtually identical to 5W-30, all the way down to -40', which is the lowest temp on the graph. Mobil tells me that the 0W-30 starts to show an advantage when the temp gets below -45', but I plan to stay away from that part of the world.

Hope this helps.

John Shiels

10w30 has served me well to 310*

Rick93Z07

5W-30 and 10W-30 served me well too. My Ford has 120+ track days on it with 5W-30 and 240K+ miles on untouched motor. 120+events x 200 mi/day = 24K track miles. Beat that.

gcrouse

Just something to keep in mind- The oil used in the multiweights is the lightest viscosity; i.e. 0w-30 is made with 0 weight oil; 10w40 is made with 10 weight oil. What gives the highend viscosity are added polymers which ball up at low temps, but unwind into strands as temp increases. This acts like the heavier oil as far as flow rate, but shear strength of the polymers is never as good as actual heavier oil.

In recent years lots of manufacturers have switched to really light oils to reduce friction- notice the markings: "SG Energy Conserving." Not necessarily the best stuff when you're running hard. If it doesn't get too cold where you live, nothing wrong with running a straight 15-30 weight oil and making sure you're fully warmed up. I use Valvoline VR30 racing stuff myself.

Here's a really good article explaining everything, plus data from many oil brands:
http://www.repairfaq.org/filipg/AUTO/F_oil_facts.html


[Modified by gcrouse, 2:15 PM 2/20/2002]

Rick93Z07

If you want maximum RWHP, run the thinnest stuff that provides adequate pressure at high temps and meets spec. Many NASCAR and CART teams are now running 10W-30 as opposed to the heavier straight weights. With proper clearances, cooling and oiling precautions this allows you to put the power down and win. The only shortcoming to thin synthetic oil in a modern V8 car is excessive windage and slosh. Shear due to excessive temps is almost unheard of. Certain pan and pickup designs are more vulnerable (C5) and this can result in momentary oil starvation under high G situations. Thicker oil tends to remain in the bottom of the pan instead of sloshing around. The situation is magnified with race rubber.

Mike Schriber

Ah, someone kind of pointed it out...

5W-30 and 10W-30 are both 30 weight oil once you get to operating temperature.

I've run 5W-30 on the street and the track with no known issues. I've had oil temps in excess of 290 with no evidence of burnt or broken down oil. I change my oil after every track event (and before too if I've put a lot of miles on the car between events). Not running old oil can make a big difference.

Mike :flag