Oil for 70,000km 3B Engine (1 Viewer)

[roscoFJ73]

No it won't.

Obviouslessly Dougal it doesnt go exactly like water, because its not water. But believe me coming down the Goldfields hwy in the middle of summer certainly thins it out. Which is why i use 20/50

 

[Dougal]

Obviouslessly Dougal it doesnt go exactly like water, because its not water. But believe me coming down the Goldfields hwy in the middle of summer certainly thins it out. Which is why i use 20/50

Yes it thins it out, but it doesn't thin it out beyond what is expected or required for the oil to work.
Heavier oil just costs fuel economy.

 

[roscoFJ73]

In 13 years of watching fuel 1HZ economy I havent seen it change between 10/40 20/50 or 20/60. While it may have a difference, you are not going to notice it.

 

[Darkwing58]

I have heard that zinc additives are fairly worthless as the chemist would need to have the particular oil you are using when designing the additive to ensure it properly "mixes", for lack of a scientific word, with the brand, type or weight of oil you are using.

I learned today that few oils, and Rotella specifically, no longer contain any zinc due to the advent of "clean diesels."

So again, that begs the question, what is really the best oil for these flat tappet B engines?

Castrol markets a "Classic XL" line of retro oils. Recommended for pre-1980 cars, their multi-grade 20W-50 is formulated with high-quality mineral oils plus selected additives for older technology and classic car engines. Also in the "Classic XL" line is a 30W oil for pre-1950 vintage and classic cars. This mono-grade oil can also be used in most types of manually-operated gearboxes.

Lucas "Hot Rod and Classic Car" motor oil is designed for use in all classic cars, sports cars, and muscle cars without catalytic converters. It is also suitable for racing applications. It is not recommended for late-model passenger car use.

use Lucas in my 1978 MGB.

AMSOIL Break-In Oil, for example, contains 2,200 ppm zinc and 2,000 ppm phosphorus. They also make a high sink oil for after the breakin

jusy my 2 cents worth.