Which oil do you use

[Crusin]

Having a ZR-1 I am aware the engine requires more zinc content and was informed Amsoil Z Rod 10/30 was the best oil for the LT 1.
Thanks for the replies.

[mlipmd]

And how about Mobil 1 0W-40 European Car Formula with the high levels of ZDDP recommended by the gurus? Works great.

[spork2367]

Originally Posted by mlipmd

And how about Mobil 1 0W-40 European Car Formula with the high levels of ZDDP recommended by the gurus? Works great.

WAY outside of recommended viscosity range. Made for modern cars with very different requirements.

https://www.mobil.com/lubricants/-/m...ide-rev-31.pdf

[mlipmd]

Don't necessarily agree with that, many of the gurus recommend 10W-40 or 15W-50, the 0W has little effect, just makes it easier to start or use at lower temps.
And it's good enough for a Porsche or Audi A4 but not a 'Vette?

[spork2367]

Originally Posted by mlipmd

Don't necessarily agree with that, many of the gurus recommend 10W-40 or 15W-50, the 0W has little effect, just makes it easier to start or use at lower temps.
And it's good enough for a Porsche or Audi A4 but not a 'Vette?

You don't have to agree with me but any internal combustion engine design engineer worth having would disagree with you. I know, I work in a company that designs and builds piston engines.

Considering startup protection is critically important to engines, this plays a big part in viscosity selection. It also plays a big part in combination with internal clearances of the engine.

While the designation 10W-30 means that the engine oil will flow like a straight 10 weight oil at low temperatures (hence the "w" for winter), the second number doesn't mean the viscosity increases as the temperature increases. It essentially means it offers the same protection as a straight 30 weight at 212 degrees F plus.

The lower overall viscosity can lead to low oil pressure, often between bearing surfaces, not necessarily on your relatively inaccurate dash gauge. In an engine with a complex oil pressure driven chain tensioner, flat tappet cam and machined aluminum cam journals, that's not a risk I would take. Especially considering most aren't driving their car in the winter where extremely low startup temps would be a problem.

The LT-5 engine clearances were not built around 0W-40 engine oil. Your comparison to a Porsche is irrelevant. Porsche what? Run 0W-40 in an air cooled 911 or 914 and see how long your engine lasts...

[mlipmd]

Read through this thread:
https://www.corvetteforum.com/forums...0-vs-0w40.html
And the higher levels of Zinc and Phosphorus are what are reccomended by MH and others for the LT5 and that's what this oil contains, same as the beloved Amsoil but way less expensive. You pay your money and make your choice, and it in reality it probably makes very little difference in the end.
And for what it's worth, I have no problem with low oil pressure, on startup or at any other time.

[spork2367]

Originally Posted by mlipmd

Read through this thread:
https://www.corvetteforum.com/forums...0-vs-0w40.html
And the higher levels of Zinc and Phosphorus are what are reccomended by MH and others for the LT5 and that's what this oil contains, same as the beloved Amsoil but way less expensive. You pay your money and make your choice, and it in reality it probably makes very little difference in the end.
And for what it's worth, I have no problem with low oil pressure, on startup or at any other time.

The zinc content alone is not the be all end all. On top of that, there are plenty of options that have the ZDDP and meet the correct viscosity requirements. If saving 30-50 bucks a year on oil is making or breaking your budget, high performance cars may not be for you.

Like I said in my earlier post, your oil pressure gauge isn't going to tell you if you have insufficient oil pressure at your cam journals or main bearings. It's a measure of overall system pressure, and a crude measure at that.

There are lots of options that aren't much more than the Mobil 1 FS that are the correct viscosity for the engine. Unless you're looking at the Kinematic Viscosities and VI, the viscosity designator on the bottle can be very misleading.

If you're in Crawfordville Florida, per your info, you are never going to have a cold enough starting condition to require a 0W oil. Your winter average low is 50 degrees. But it's your engine, run what you want.

[viper107]

so what is it, 10w40 or 10w30, i run a penn green oil in mine at 10w40- what weight do you suggest

[CamP]

Viscosity really depends on a particular engine's bearing tolerances. Some are tighter than others, and produce higher pressure at hot idle. Those engines can sometimes use 0w and 5w weight oils. If you see over 40psi at hot idle, you can lighten the viscosity a bit.

Loose engines with lower hot idle pressure can use heavier oils.

[george1945]

New engines have extremely tight tolerances. The LT-5 engines are sloppy by comparison. They also did not have to contend with fuel economy standards the newer engines are required to meet. Thinner oils were a means to that end.