ZDDP

[Cedar]

I've been browsing the net for as much engine oil info I can find, and it strikes me that on this forum almost nothing has been said (I recall a single post by ukkid35)about ZDDP (Zinc dithiophosphate) as an anti-scuffing agent in oil. It's regarded as an essential anti-wear additive for "older" flat tappet engines like we have especially with those agressive cam profiles. Zinc and phosporus levels (the main components of zddp) have gradually been lowered in SL and even more in current SM and SN oils to aid the longevity of catalysts (which a lot of us don't even have). A few calls to tvr garages didn't reveal much more than "we use brand x or Y in viscosity x or y because we always have" but it seems the make up of oils is changing in recent times without most of us noticing. Seems to me this isn't an issue for 99% of motorists, but could be for us..

[K4TRV]

Have a look here at Frost's Web page:
http://www.frost.co.uk/automotive-oils-additives-f...

Think that's what you're looking for!!

I was browsing for POR 15!!

Trev

[ukkid35]

My understanding is that the complex detergent packages in modern oils need to be formulated in conjunction with the ZDDP, therefore simply using an additive may not have the desired results.

[K4TRV]

ukkid35 said:

My understanding is that the complex detergent packages in modern oils need to be formulated in conjunction with the ZDDP, therefore simply using an additive may not have the desired results.

Possibly..........!

The "blurb" from Frost states, if you didn't read it:

"Historically, the anti wear additive used in the majority of oils was a compound known as ZDD (ZincDialkylDithiophosphate). The phosphorous content of ZDDP and its ash, has a detrimental effect on catalytic emission systems. This has led to new oils being developed to meet modern regulations, which have reduced levels of ZDDP. These new oils may cause serious problems in a classic engine. Add one bottle of ZDDP at each oil change to protect the gears, cam and followers and add life to your engine.

My money is on protection of the Catalyist for the demise of ZDDP?

But, you pays your money.....!!