[MatthewAMEL]

Originally Posted by Evansa22

Before the factory fill was switched to 0w40, standard was 5w30 so shouldn't be an issue running 5w40

So...you don't think they switched for a reason?

[getchapull]

The reason for the switch was for track usage. GM says you can use the 0w-40 for daily and track usage.

That's why I use 5w-30

[Gunkk]

Originally Posted by Evansa22

Before the factory fill was switched to 0w40, standard was 5w30 so shouldn't be an issue running 5w40

5w40 is roughly 30ish% more viscous than 5w30 at 40C (80 vs 64 cst aka mm2/s). More than twice the difference of 0w40 (71) over 5w30.

Why not just throw some diff oil in there... it's a higher number so it's gotta be better, right? .... <insert starwars meme> RIGHT?!

Originally Posted by getchapull

The reason for the switch was for track usage. GM says you can use the 0w-40 for daily and track usage.

That's why I use 5w-30

0w40 is OK on the track in a ZL1, not a ZLE due to higher lateral G forces capable of starving the sump.

And no this is still not an oil thread.

[Evansa22]

I'm sure they switched for a reason, what is the reason though? For all anyone may know it may have been cheaper so GM said go with it. I personally have never seen anything on the reasoning but I've also never researched the subject.

My reasoning was they said it was OK to use 5w30, then they decided to make 0w40 the standard. If it's ok to use both weights, then why not 5w40? It's not outside of they're spec on either side of the spectrum. You're very right gunkk, heavier weight isn't going to be better because it's heavier, the quality and make up of the oil will determine it's wear properties. At least from what I've read on the forums.

[SFV1LE]

FWIW, I used Valvoline Dexos 2 5w40 MST a couple of times because it was Dexos 2 and so much cheaper and easier to find than M1 ESP 0w40. I'm not worried about 0w vs 5w here in CA, it's usually warm.

After 1 year of trying 5w40 MST for street I stopped putting in anything but M1 15w50, I track so often it doesn't make sense to use anything else. I change it after every 4 track days.

After 17k miles my 100% stock 2018 ZLE runs strong, still dynos at or over GM rated HP, and never burns a drop of oil during 4 track day intervals (+ some So Cal canyon driving).

[Drnick]

Another oil thread Off the rails again,my god!
PS at least SFV partially answered my question
Thanks SFV

[Camaro1973]

Originally Posted by Drnick

Another oil thread Off the rails again,my god!
PS at least SFV partially answered my question
Thanks SFV

Well I mean you did ask the same repetitive oil question that’s been answered on here about 100 times.

[Drnick]

I was asking specifically if anyone was using a 5
Weight oil instead of a 0 weight oil, not about
What brand of oil, or any other oil weights!

[ZX-10R]

Here's the truth: "zero" weight oil is a marketing gimmick, and manufacturers recommending ultra thin oils is a strictly concession to the hyper fuel economy agenda, rather than longevity of your engine

On the flip side, 40+ weight is too heavy for any street engine (and questionable benefit for a race engine). GM's call for 40+ in the Camaro is strictly to mitigate oil starvation during high G loads when cornering with a wet sump. It again has nothing to do with engine longevity and those thick oils are have terrible cold flow properties. Who knows, may be a contributor to oil pump failures

Run 5W-30 or 10W-30 in any engine and you will be fine. Turn off the noise. My brother worked for GM Advanced Vehicle Engineering over 30 years

Dexos is bs, don't worry about it. Amsoil Signature exceeds any standard out there

[george]

@ZX-10R:
Could the oil pump have anything to do with the change?

[ZX-10R]

No...it's a flawed design. My only point is higher cold pressures (with high viscosity oil) *may* be a contributor. Plus heavy throttle before oil reaches temp, which probably takes a good 15 minutes on cold days and how many people wait that long?

[Rock-It Man]

Originally Posted by Evansa22

Before the factory fill was switched to 0w40, standard was 5w30 so shouldn't be an issue running 5w40

0w40 as standard is superior tp 5w30 at both the cold and hot ends of the operating range.

So, other than following the GM recommendation for track use, what would be the point of not using 0w40?

[ZX-10R]

Originally Posted by Rock-It Man

0w40 as standard is superior tp 5w30 at both the cold and hot ends of the operating range.

Based on what? Look up cold viscosity for both

Higher viscosity at high temp isn't necessarily "better", it actually robs power and doesn't flow quite as well

So, other than following the GM recommendation for track use, what would be the point of not using 0w40?

See my post above. 5W-30 or 10W-30 is all you need unless you track the car and are worried about oil starvation during aggressive cornering. The vette dry sump set up is superior

[Rock-It Man]

Originally Posted by ZX-10R

Based on what? Look up cold viscosity for both

Higher viscosity at high temp isn't necessarily "better", it actually robs power and doesn't flow quite as well



See my post above. 5W-30 or 10W-30 is all you need unless you track the car and are worried about oil starvation during aggressive cornering. The vette dry sump set up is superior

And so you know something the GM engineers don't?