our Vintage Cars
In recent years engine oil suppliers have
modified their oils to meet emission standards
and to prevent damage to Catalytic Converters by
removing the additive ZDDP.. "ZINC"
ZDDP is or was a additive used to prevent damage
to sliding surfaces such as solid lifters
dragging on the cam shaft lobs. With the use of
roller lifters on most if not all modern cars
the additive was no longer necessary.
So the question, that's just fine for modern
engines but what about our vintage cars? There
are reams of articles arguing for and against
the effects of using the modern oils in our
engines. A search on Google will give you a full
So in summary it appear if you you have ultra
high compression engine with heavy pressure
valve springs and solid lifters and use the
modern oils that don't have ZDDP you are likely
to experience excessive wear on the cam
resulting in a "Flat Cam".
Does it effect our old vintage auto engines with
moderate to low compression and the valve
springs are of moderate to low pressures.
Probably not unless you do lots of driving, with
the exception of the early Cadillac V8 engines.
But if you are like me and a lot of others I
want that extra protection provide by ZDDP. My
feeling, if it was formulated and used when the
cars were built then it must have been
From what is written it
appears that about 0.11% ADDP is what was in the
oils prior to the change. ZDDP can be purchased
and added to the oil. See on supplier at this
Or here is a list of oil suppliers and the
amounts of ZDDP "Zinc" in there oils..
Chevron Delo 400
Havoline Formula 3
Pennzoil GT Perf.
Pennzoil PLZ Turbo
Quaker State Dlx.
Spectro Golden M.G.none
11% Zinc (Minimum)
Exxon High Performance .11%
Valvoline All Climate .11%
Chevron Supreme .11%
Exxon Superflo Hi Perf 135 .11%
Castrol GTX .12%
Unocal Super .12%
Valvoline Synthetic .12%
Shell Fire and Ice .12%
Exxon Superflo Supreme 133 .13%
Exxon XD3 Extra .13%
Valvoline Turbo .13%
Spectro Golden M.G. .13%
Shell Rotella w/XLA .13%
Shell Super 2000 .13%
Exxon XD3 .14%
Shell Truck Guard .15%
Spectro Golden 4 .15%
Mystic JT8 .15
Valvoline All Fleet .15%
Kendall GT-1 .16%
Valvoline Race .20%