20 replies to this topic

[coopertaz]

I also usually run in on cheap oil for the first 300 or so miles then flush and change oil and filter to a quality oil ( as advised by rolling road operator, now sadly retired) before this i used good oil from start up. views on this?

Edited by coopertaz, 26 August 2026 - 10:02 AM.

[Icey]

The price of the oil isn’t the important part for run-in. From Calvers guidance it’s about avoiding friction modifiers which might affect ring bedding-in.

And personally, the idea of using cheap oil during the most sensitive part of an engines life seems counterintuitive.

[pete l]

Are we talking oil with zinc in it ?

[coopertaz]

The price of the oil isn’t the important part for run-in. From Calvers guidance it’s about avoiding friction modifiers which might affect ring bedding-in.

And personally, the idea of using cheap oil during the most sensitive part of an engines life seems counterintuitive.

 it seemed that way to me too but his point was that cheap mineral oil allows the rings to bed in correctly. i usually run millers 20W50 semi synth. once bedded in but i now usually run in on cheap (supermarket) mineral oil, but am considering millers 20W50 mineral instead, most oils appear now to be low in zinc to avoid catalyst damage. But just getting an idea of what other people use

Edited by coopertaz, 27 August 2026 - 03:03 PM.

[Icey]

I get the point, but it sets the wrong precedent. It’s not that it’s cheap you buy it, it’s that cheap oil doesn’t/didn’t have fancy additives. So you need to be buying based on requirements rather than price.

I buy specific run-in oil because at least then I know what it does/doesn’t have in (funnily enough, I get it from Mr Calver).

[sonscar]

I use ultra 20/50 from smith and Allen in bulk.1500 ppm zddp used in the mini,mgbv8 and mgb 1800 for as long as I can remember.This is purely my choice.Steve..