Everyone's Favorite Subject (Oil)

[efficient]

Regular Castrol synthetic 20-50.

[gath]

Shell Rotella T 15W-40 HD diesel oil with Lucas Oil Stabilizer which, seems to work well for me.

[estoguy]

I've been using the Castrol Edge 5w50 for about a year and half. Seems to do the job and it goes on sale often up here at Canadian Tire, so I get it for a little bit more than I'd pay for dino oil.

[dnguyen1963]

15W-40 Diesel oil year round. When I lived in Wisconsin, I tried lower viscosity oil for January and February for better start-up, but once the engine warmed up, it was way too thin.

[3vilE30]

15w-40 diesel oil year around
Mobil Delvac or bust.

20w-50 is recommended but isn't as sheer stable as diesel oil.

Royal Purp is already over doing it, 10w-60 is over kill unless your doing like 10k oil change intervals which you shouldn't be doing on a m20.

Diesel oil + 5k oci + whatever filter = squeaky clean valvetrain on a rebuilt motor.
The additive package in diesel oil is bolstered. When compared to regular oils, you won't find anything nearly as good without spending $$$ on top tier oils I'm talking about redline and amsoil.

[MR 325]

Valvoline VR1 20w50. 8)

[indecline]

Just curious to what everyone uses in terms of oil. I'm currently using Royal Purple 20W50. It's been working fine for 1K miles. I'm thinking of switching over to 10W60 next oil change.