What oil comes in an 03

[CobraEd]

I want to change the oil at about 500 miles with generic dinosaur oil (Valvoline 10-40) before going to Mobil 1 at about 1,500 miles. I want to use the non-synthetic at the 500 mile mark to make sure the rings seat and I don't glaze the cylinders. But if the car came with synthetic from the factory like the new Corvettes, I will go right to the Mobil 1 at the 500 mile change.

So having said all that, does anyone know what these come with from the factory?

Ed

 

[JoeAsheville]

It's not recommended to use anything thicker than 30 weight, do a search on Cobra'03 and his posts willl come up. He is a well respected petrochemicals engineer that posts some informative stuff on here. :read:

What he is doing, if memory serves (correct me if I'm wrong Cobra'03) but he changed out at 500 miles to regular dino oil like what you are suggesting (I forget the weight he mentioned) for about 1500 miles then he will switch to a synthetic, either 0W30 or 5W30.

I personally prefer Mobil One as it is more commercialy available if I need a quart, and the 0W30 concept sounds perfectly rational to me.

 

[Ron Rubsam]

03 oil from factory

It come with 5-20 semi synthetic ford oil

 

[david smilovic]

Dino for 1500 is good but not necessery.Once you go back to Syn check out Red lines and Amsoils web sites.Amsoil is the finest and I Think???? they have a 5-20,I will continue using stock Ford replacement with Red Line for the gears.Dave S.

 

[Cobra'03]

Please let me makes ure we are very tight about terminology

1) The factory fill is a synthetic Blend, not semi-synthetic, 5w20. To me semi-synthetic would be a hydrotreated high quality mineral oil like Pennzoil's Pure Base multi-vis

2) Amsoil's 5w20 is a relatively cheap Group III not of the same quality as their 5w30 or 0w30 Series 2000 true synoils. It is comparable to Pennzoil's synthetic, Valvoline's, etc. I believe Mobil 1's formulation, with both hydrocracked and PAO, is better. And as Joe Asheville says, easy to source.

3) Red Line makes a 5w20, with polyol ester base (Group V) and excellent additives.

4) I would not use a 5w20 mineral or synblend in my car - see my explanation in the "Why no synoil" thread

5) I like the Amsoil 0w30 Series 2K as it combines the properties of a 5w20 and better protection. It has an outstanding anti-wear, anti-friction package.

All of the oils mentioned are adequate or better for protecting our cars.