Chaps, I understand the oil companies have removed zinc and phosphorus from their additive list and this is causing accelerated top end wear, esp cam wear on older vehicles. - Several classic owners in my area have recently had to do cam changes on their vehicles because of this.

I'm no expert but have been advised that you need to either start using diesel engine oil that is high in zinc and phosphorus (check the spec) or you need to add something like this: http://www.compcams.com/Produc...Lubricants%27-0.aspx

I understand the older engines need something that has a high ZDDP content.

Steve,

Can you post the analysis of some engine oils please?

While what your claim is possible somehow I doubt that anti wear additives have been taken out of our usual motor oils.

no mate, as I said in my original post, I'm no expert and certainly I'm afraid I'm not a chemist but if you do a Google search of your own, you'll find there appears to be a fair amount of evidence that it's true.

I've found various theories of why it's been removed. Some say to assist the catalyctic converters, some say it's to appease the greenies and others say it's simply a matter of cost.

FWIW,

Here's one explanation I've just been given:

"The oil companies removed zinc and molebdenum from the oils to protect the catylitic converter on engines that burn oil. These two metals destroy the catylist. Zinc forms a barrier between two pieces of metal so if you break through the layer of oil (which happens often), you still have protection against damage"

Here is a good write up on the subject:

http://porsche356registry.org/...r-cooled-engine.html

If you think this crap is bad enough, Illinois just banned all lead wheel weights to be active jan 1, 2012. EPA will fine you $5000 (reportedly is the number I heard from a reputable source) if you balance tires and they even find lead weights on your premises.

FWIW, I've been talking to several fundis on the subject and the concensus of opinion is that for my engine at least (AMC V8 5.7 litre), I'm best off using Valvoline Off-road VR-1 oil OR adding something like Comp Cams Engine Break In Oil Additive or other additive that's high in ZDDP.

All the "good stuff" has been taken out of diesel oils due to the concern over plugging particulate filters in exhaust systems. The API rating of diesel oils used to be CI4 or CI4+. +being the better. Now they are CJ(the only stuff you'll find on the shelf)rated and SUCK! After several inquiries it has been discovered the major oil companies will continue making CI4+ until 2012......If ya wants it ya gotta buy it in 55gal drums.