I am not a 100% sure but I think the highest spec oil to be used in
classic car engines is SG/SH. 20W60 may interfere with the oil flow as
20w50 is the usual specified oil for classic cars. The higher the
numbers the thicker the oil hence a higher oil pressure but a reduced
flow. Oil flow however is all important in an engine, more than pressure
(within limits of course).
Kees Oudesluijs
Op 11-5-2017 om 1:07 schreef Bob Spidell:
> I was at my favorite local parts house today and noticed, as reported
> by others that VR1 is back on the shelf after mysteriously
> disappearing a year or so ago. Good deal, I think, then I noticed the
> label is slightly different than the stock I bought a year or so ago;
> in particular, 'HIGH ZINC' is shown prominently on the front label (my
> stash doesn't). Also, the 'new' stuff is rated SAE SJ only, whereas
> my bottles say 'EXCEEDS API SERVICE SGCD And All Pending API Gasoline
> Categories Exceeds API Services SN/SM/SL' The cam makers generally
> say that SN and SM are not suitable for flat tappet engines (not
> enough zinc and phosphorous). SN/SM--dunno about SL--are supposedly
> OK for engines with catalytic converters, which implies less zinc.
>
> Anybody know for certain know what gives? My theories are:
>
> 1) Valvoline pulled their stock and simply relabeled their product SJ
> to make it clear it shouldn't be used in cars with cats
>
> 2) The old VR1 WAS acceptable for cars with cats, implying zinc
> content of no more than 800PPM or so, and they have reformulated the
> oil with more ZDDP, which required the relabeling. I hope this isn't
> the case, as I bought a boatload of it because it appeared to be an
> off-the-shelf oil with decent zinc and phosphorous content.
>
> The plot thickens (it's now 20W-60).
>
> Bob
|