so if you read my Previous thread yeah i blew my LS3 within 4 months. so trying to not repeat my mistakes ive stepped up to a better build. but so many have weighed in on my choice in oil(s) that im honestly curious because there seems to be so many different opinions all with some merit. 5w30 is the standard for the LS3 it seems and its what factory spec is.. i called dart and even they said 5w30. but if you look at like the ZL1 1LE they recommend a 15w50 for track days and it makes sense. so what are people using and why? ive upgraded my oil cooler and placement to hopefully keep the temps down so i got that going for me.

5w30
10w30
15w50

what are you using and why?

 

5w30, been using it for 10+ years in many different fbody's and a few ybody's because that's what it says to use...never had an issue.

 

Go with what the engine builder recommends

 

I Use 20-50 VR1 in all my fbodys.

 

For your appliation, assuming you have a good functioning cooler, use a quality 30 weight synthetic. A heavier weight oil isn't necessary unless it is breaking down from extreme temps. Additionally, running a heavier oil than necessary will create higher oil temps because it is harder to pump.

I've worked on LS engines that have raced in Grand Am, SCCA world challenge, SCCA trans am, and NASCAR K&N. All of those engines run with 30 weight oil and a proper oil cooler. My personal track car has always run 30 weight with a cooler, and that LS1 has seen 70k miles of abuse at autocross and the road course.

 

As the tech to push more power better mileage etc has moved up, so has the complexity of oils, my KTM street bike uses 0w60 (Made from unicorn blood based on the price...) ,, Assuming the engine was built with stock main and rod clearances, I'd stick with the 5w30 as recommended possibly running 10w30 if the weather was really hot.. and I second the "good cooler" recommendations..

 

I run 5w30 in the winter months and 10w30 in the summer and haven't had any issues. My oil pressure runs in the 60s and idles in the 50s. I'm running an LSX block with Morel lifters, a high volume oil pump, the Moroso 21150 pan and the Milodon oil filter relocation kit. I feel if you have to run a thicker oil to get your oil pressure where you want it than you have other issues such as worn bearings.

 

Here's some of that unicorn blood you had mentioned earlier.

 

see thank you. this is good info.

 

15-50 or 20-50 on a road course. period.

30 weight will turn into water under that much stress and prolonged heat. The grand-am/scca challenge and nascar cars are POOR candidates to evaluate oil weight on - those engines last a season at best, and 30wt is a power consideration, NOT a wear one. If you want the thing to last, use thicker oil. The 15-50 M1 also has high ZDDP levels, it's the last of the M1 that does. Great oil.

 

anyone else wanna chime in on this???? i see your point very well. what about a 5w50?

 

@71_t/a

 

You should run the oil that is the correct viscosity for your engine at the oil temps you typically run at. Which means it depends.

For a completely stock LS, it's usually 5W30, the "30" weight being rated at 100C (212F). If your oil temps at the track are 270F, for example, you should run a thicker oil so that the viscosity isn't too thin at those temps. You can tell if this is an issue because your oil pressure will be too low. If oil pressure is too low, you can lose the "hydrodynamic wedge" that the bearings are floating on, and will result in increased bearing wear. But that thicker oil will be too thick at lower temps on the street.

Long story short, unless there is something weird about your engine or you're running in extreme temperatures, run the factory recommended 5W30. If it's a built engine run what the builder recommends. At the track, if your oil temps are high and your pressure is too low, run a thicker oil just for track use.

Also, look at the actual viscosity rating specifications for the oil, not just the xWxx numbers. The actual viscosity of two 5W30 oils can actually be quite different.

 

i was just typing you out an email to ask this question..

also to everyone else, improved racing are amazing people and their tech service has been the best.

 

so for CA would a straight 30 be fine as well?

 

I just started running Rotella T6 5w-40 in my cammed LS2 with a Melling high pressure pump. No issues so far +/-1k miles

 

If the new engine has a warranty, and the warranty could be voided by not using the engine builders recommended fluids, I'd definitely stick with their recommendations at least until the end of the warranty period. After that, change at your own risk.

Based on prior research on the BITOG forum, for street driving on stock bearing clearances any 5W30 should be fine. If you have higher than stock valve spring pressures, an oil with extra ZDDP wouldn't hurt. As IR pointed out, look at the actual specs on the oil, such as cST, and not just the "xx W YY" generic label.

But personally for street use I'd go with one of these:

M1 0/40
M1 5/30
Redline 0/40
Redline 5/20
Pennzoil Ultra 0/40
Joe Gibbs LS30

For track use, get an oil cooler such as a Setrab TOC-300 oil/water heat exchanger. Also look into Mobil1 Race 0W30 or 0W50 oils ($15/qt).

 

No, never run a straight oil, it will be far too viscous when cold. That's why the multi-viscosity oils exist for automotive use.

 

 

That's it in a nutshell....