ZDDP as an additive

[jameshoward]

In this thread there has been some brief (tangential) discussion about using ZDDP additive to oil: http://www.sl113.org/forums/index.php?topic=22823.0

I wanted to start a new thread rather than interfere with Brad's genuine issue, which is an oil leak.

Having just changed my oil at the weekend - I use a classic car oil from Halfords (it's a UK autoparts store like any of the big US chains) - that allegedly has things like seal conditioners and 'additives' to prevent wear in older engines. I've used this for about 4 years and have been extremely happy with the oil. I have no leaks, and my car uses no oil. I change it every 2000-3000 miles or every year. (Incidentally, I may try Miller's, as in all the stuff I read last night, they got a good writeup, although it's twice the price...).

I spent some time on the internet last night reading about ZDDP. You can buy the additive in the UK for £16 (delivered) from Frost or £15 from Amazon. My oil is £19 for 5L at standard price; often cheaper when on special. I can't seem to justify the additional £15 from what I've read. There's debate all over classic forums on this subject, but as ever, nothing conclusive. I'd also tend to subscribe to the view of many that oil manufacturers have a pretty good idea what needs to go into oil. Then there's the bit about getting the right 'dose' of ZDDP. I have no idea what that is, because in the UK at least, oil manufacturers aren't required to disclose what's in their oil. So, my oil could be ZDDP steroids, or devoid of the stuff. I have no way of knowing. Then there's the fact that the car has run perfectly well without ZDDP for as long as I've had it, and presumably beforehand.

I'm all about looking after my car and spend more time doing that than driving it, it seems, but I can't seem to find anything that suggests ZDDP is worth the expense. That's not to say I think people who add ZDDP are taking crazy pills; it's just that I'd love to see something objective and conclusive one way or another that could help with my decision making.

Separately, I have used BG 44K to good effect, but that goes in the fuel tank. I think it makes a discernable difference and would recommend it once in a while. It is pricey, however.

Any thoughts?

[gnj588d]

There is a very good article in the June issue of the Gazette {British Mercedes club Magazine} about oils for classic cars
I read somewhere never use any addatives as the oil companies spend tens of millions on research for the best possible performance
and longevity for our engines it says adding extra addatives to the oils is a waste of money and could upset the whole chemical ballance of the oil and could render the oil useless in the worse case scenario, you need an oil with a high zinc content ie 900-1.100ppm for flat tappet valves, I have been using Valvoline VR1 20-50 racing oil to great affect, Buying good quality oil is the best route. I buy it from Europarts about £25-£30 for 5 Ltrs think you can get it on ebay cheaper with free postage.Hope this helps Cheers.Mike.

[Paul & Dolly]

I also use Valvoline VR 1 Racing 20/50, and change oil  each year regardless of mileage.

I believe the UK/Europe supply was reformulated to comply with various Euro Specs a couple of years ago, and despite my repeated requests to Valvoline in UK and the Netherlands they refuse to state the "Zinc" of other component values in this new spec.
The USA site gives the USA spec which is fine.

I keep using it though.

Paul

[Raymond]

When zinc was first removed from motor oil, there was a lot of comment by English car owners in the US that their cams were wearing out at alarmingly rapid rates.  The German car owners didn't report such problems.  The common wisdom was that the chromium or molybdenum used in the German wear surfaces was more resistant to wear and didn't need the zinc as much.  I'm not a metallurgist so I don't really know. 

I can by a ZDDP additive at the local auto parts store for about $9.  I don't.  I've been running Mobil 1 15w50 at 3,000 or 1/year intervals since I rebuilt the engine in 2005. 

[Jonny B]

A topic fraught with disaster (to the poster that is!). The view I subscribe to is, that if you want the higher ZDDP find an oil that contains it (the racing oils, some of the diesel engine oils,etc). I am fully on board with the comment that using an additive is just not the way to go. Oil manufacturers do indeed spend a lot of money getting the combinations right, testing them and blending them. I have a very difficult time with just putting an additive into the engine and hoping that it is going to mix in properly etc. Richard Simmonds put together an excellent article for the MBCA - published in the Star magazine a few years back typing to this very issue. Am traveling this week and am not able to provide the reference issue. I know that a reference was posted on this site.

[hauser]

My Metric rebuild package states to use only Castrol GTX 10-40.

[Richard116e]

Hi

I can add that I have used Castrol Classic XL 20/50 in my Dads 1965 230sl for the last 4 years with no detected problems.  I am biased as I only stock Castrol.  The 20w/50 range does exceed 1000ppm ZDDP and is the correct formulation produced from Castrol in 1962-1980 (GTX20w/50).  Happy to supply fellow owners.........

Classic Car Oil London

[Paul & Dolly]

That is good to know, Richard,
I used to use Castrol XL30 and XXL 40 when I had the Alvis,

Paul

[jameshoward]

Hi

I can add that I have used Castrol Classic XL 20/50 in my Dads 1965 230sl for the last 4 years with no detected problems.  I am biased as I only stock Castrol.  The 20w/50 range does exceed 1000ppm ZDDP and is the correct formulation produced from Castrol in 1962-1980 (GTX20w/50).  Happy to supply fellow owners.........

Classic Car Oil London

Spill the beans, Richard! Name your price (and postage!!)

Or what's your website. If your right about Castrol, I'll gladly give it a go.

JH

[Raymond]

Better yet Richard, let me suggest you become a full member and post all your wares on the vendor forum.   

The debate whether the additive or the "special" oil is worth the extra money will never be solved.  Will the engine run 130,000 miles instead of 120,000?  Will some future overheating issue shorten the life of the rings?  Does one oil precipitate moisture better than another?  There are too many variables. The best answer seems still to be use a good oil and change it and the filter regularly.

[rwmastel]

I'd love to see something objective and conclusive one way or another that could help with my decision making.

James,
That would help everyone with their decision making, thereby putting the loser of that objective analysis out of business.  The consumers might not mind that, but the companies mind!  Not only do companies spend money to put their best product out there, but I assume they do their best to counter-argue any findings that make their products look inferior.

[Richard116e]

Hi

Just joined the group as a full member now.

The price for a gallon/4.54L of Castrol Classic XL 20w/50 is £26.50 and the postage with in the UK is around £10 or less and I can supply in Europe at a extra cost.  If there is enough interest we could set up some members pricing.

And James I might be able to offer free delivery to London owners as I am based in London.

My website is http://www.classiccaroillondon.co.uk/ but its not up to date and its not fully functional.

Thanks Richard

[Autobob]

In the US it is best to err on the side of caution with old cars and modern oils. To have a modern API approved rating the oils ZDDP has been lowered. This has been required as a step to reduce emissions. I run a speed shop in the US and we have seen camshaft wear issues that industry has determined to be from the reduction in ZDDP. We have also seen lobe wear in Porsches. Many Porsche cars came with Mobile 1 from the factory so owners think continuing is proper. Problem is the current oil formulas differ just as our current fuel is no longer the same. Any car prior to 1990 or any car that is exercised hard would be best to use higher ZDDP oils or use an additive like BG MOA or Redline break in additive in your API approved oil. The cans tell you what quantity to use. Worse case you will throwing a little money away instead of a lot of money later. European oils I know nothing of.

Bob

[Benz Dr.]

My Metric rebuild package states to use only Castrol GTX 10-40.

Is that during or after engine break in? You want certain parts to wear or break in to each other but you don't want it to be uncontrolled wear. There is likely no other time during the service life of your engine where engine wear will be as high.