Fact or Myth: Recent Deleterious Motor Oil Reformulation?


Is there something wrong with the way motor oil manufactureres have recently begun formulating motor oil, and if so, could Eric Peters, as a nationally known automotive columnist, do something to get this issue before the national mainstream news media? Please see links below:




It’s internet bunk IMHO.


Unless you drive an older car with flat valve tappets don’t worry about it. This article will explain very nicely:




This is not something I’m planning to lose sleep over. I plan to continue using the same oils I’ve used for years; whatever is on sale, regardless of brand. As long as it’s 5W30 and has the correct API designation I will use it.


Both of my sons have flat tappet Camaros as daily drivers and own 2 other flat tappet cars.
One Camaro has approx. 215k no-problem miles and the other is approaching 300k no-problem miles.

If oil is a problem with flat tappet cams then somebody better alert them quickly that they have problems, because it’s not going to be me.


Yeah, who’s opinion are YOU going to trust more; the people who design and manufacture engines and their associated parts or the people who fix them? Inevitably, people will come here and say they ran for years and never saw a problem so it can’t be true. If you read some of the articles you can see the facts for yourself or you can trust the opinions of people who fix cars for a living or as a hobby and only see a very limited view of the overall population of vehicles on the road.


Let me ask you a few questions.

  1. Is a flat tappet flat?
  2. It is stated by a well known cam maker that their additive should be used and the cam broken in properly for the first 500 miles. After that, use the oil of your choice.
    So, is the oil all of a sudden fine after that initial 500 miles?


I’m with OK4450 on this one.


Oh, and for REAL oil facts, go to http://www.bobistheoilguy.com/


What about newer cars with flat tappets? Some 2006 Nissan engines have flat tappets as do others.


I think you mis-understand. SM rated oils are pretty new to the market. If what these and other articles I’ve seen recently are true, your son’s Camero would not have made it this far if the older oils had been made with this new formula.


The ONLY thing you need to know about motor oil…



I’m still curious about questions 1 and 2.
:slight_smile: Anybody?


Let me ask you a few questions.

  1. Is a flat tappet flat?

What’s your definition of “flat”??? Of course it has a domed surface that rides on the cam lobe the purpose of which is to promote turning of the lifter to minimize wear.

  1. It is stated by a well known cam maker that their additive should be used and the cam broken in properly for the first 500 miles. After that, use the oil of your choice.

So, based on your interpretation then, old McDonalds fry oil would work??? Oil of your choice does not mean ANY oil. It has to meet certain specifications. Oil designed to work with flat tappet cams needs to have the additive that is no longer being added to modern formulations. What’s the big mystery?

So, is the oil all of a sudden fine after that initial 500 miles?

No, you still must use the appropriate oil for the application.


I stick with my comments on this issue and here’s why. Some of this got started by a company that regrinds cams and had a high number of failures. Their diagnosis was that “if it’s not the oil, what could it be”? That hardly sounds scientific to me.
Another site attributed cam and tappet failure on old Triumph motorcycles to the new oil.
As someone who has actually owned and built a number of these bikes I can say that every Triumph in the world has been in pieces at one time or the other. NEVER are the tappets put back into their original positions. This leads to premature tappet and lobe failure and this was a common occurrence even 35 years ago.
Since I’m a packrat of sorts, I have a small box full of old Triumph cams and tappets tucked away still; and almost all of them not useable in their current form due to wear.

Note these complaints involve cam regrinds or new performance camshafts.
As to the comment “if it’s not the oil, what could it be”? Well, it could be:
Improper break-in.
Inferior metal used in the cam blank.
Inferior hardening process. (See GM about 30 years ago in regards to cam lobe failures due to improper hardening.)
Excessive valve spring pressure caused by any one of a number of things; valve springs, valve height, valve spring coil bind, rocker arm ratio, etc.
Using SYNTHETIC oil during the break-in. No-No.

The market is glutted with performance parts now and many engine builders may not know as much as they think they do. An example could be a friend of my son who put a fortune into a new Ford engine, misadjusted the lifters, and VOILA! Knocked the cam lobes out of it within 500 miles.
Is it his fault? NO, according to him. He got a bad camshaft.

Go to a site like Crane Cams and they specify that due to the lack of zinc that PROPER break-in procedures must be used or the cam may fail. Well gee whiz.

An example from Edelbrock as to valve spring issues; scroll to page 2, step 3.
Ask yourself how many back yard techs know anything about valve spring pressures or even how to test it. It’s throw the cam in and hope for the best in many cases.

If the “zincless oil” was a problem then performance cam makers would be advising that it not be used.

This is logged out again ok4450 anyway.


Maybe they will advise against it when there is even more hard evidence proving it is all or part of the cause. IMO, there are fewer people going to the level of replacing camshafts as a performance mod than in the past yet the number of failures is certainly on the rise. To steadfastly attribute the problem to operator error is shortsighted and premature judgement just as much as those who claim the opposite. My position is to err on the side of caution and use what has worked in the past until the scientific evidence proves otherwise. Clearly, there has been a change in the formulation of the oil and there are a high rate of failures. Those are facts. The rest is speculation at this point.


Same thing. As I recall, several pre-prodution camshafts(with aggressive profiles) tend to bite the rocker arms even if it had same material/surface treatment to the original. Also, valve springs with higher spring rate encourages this kind of issues.

Some of the rocker arms get bitten by the camshaft for some unexplicable reasons and one of them try to confront. After the fight, the one get thrown away caroming off the others that I have seen before, through the CCD cameras put inside the cylinder head.