> Wasn't the original factory recommendation straight 30wt, summer,
> straight 20wt winter? ( although I'm presently using Brad-Penn 20W50 in
> the TR3).
The owner's handbook in 'The Bentley' (which was 2nd edition IIRC) has:
Over 70F/20C : 40 weight
40 to 70F/0 to 20C : 30 weight
10 to 40F/-10 to 0C: 20 weight
-10 to 10F/-25 to -10C : 10 weight
Below -10F/-25C : 5 weight
(Were those guys optimists or what?!)
The owner's handbook was later renamed to "Practical Hints for the Maintenance
of the Triumph T.R.3", and the 6th edition (which I believe was published
around 1960) had a similar chart except that 20W40 was allowed for the highest
temperature range, and 10W30 was allowed for all others. (and the 5 weight
line was deleted)
I also use 20W50 (Valvoline full synthetic), but I haven't actually done a
full engine rebuild since around 1975 and so my oil pressure never goes too
high.
-- Randall
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