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 days reading.
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 important.
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 web address www.MotorHeadOil.com
Or here is a list of oil suppliers and the amounts of ZDDP “Zinc” in there oils..
0% Zinc
- AMSOIL
- Chevron Delo 400
- Havoline Formula 3
- Mobil 1
- Pennzoil GT Perf.
- Pennzoil PLZ Turbo
- Quaker State Dlx.
- Quaker State
- Red Line
- Spectro Golden M.G.
11% Zinc (Minimum)
- Exxon High Performance
- Valvoline All Climate
- Chevron Supreme
- Exxon Superflo Hi Perf 135
12% Zinc
- Castrol GTX
- Unocal
- Unocal Super
- Valvoline Synthetic
- Shell Fire and Ice
13% Zinc
- Exxon Superflo Supreme 133
- Exxon XD3 Extra
- Valvoline Turbo
- Spectro Golden M.G.
- Shell Rotella w/XLA
- Shell Super 2000
14% Zinc
- Castrol
- Exxon XD3
15% Zinc
- Shell Truck Guard
- Spectro Golden 4
- Mystic JT8
- Valvoline All Fleet
16% Zinc
- Kendall GT-1
20% Zinc
- Valvoline Race