[The Champ]

Article in Motor Trend on the benefits (or lack there of) on running high ZDDP diesel motor oil in your car:

"Is Diesel Motor Oil the Right Choice for a Gasoline Engine?"

https://www.motortrend.com/how-to/di...765D12CFD72326

I never thought it was a good idea, but after reading this, I understand it's really a bad idea.

Zinc And Engine Speed

Why does this matter? Because the type of ZDDP in a diesel engine oil is not the same as the ZDDP in a gasoline engine oil. This is an important difference; diesel engines run at lower rpm than gasoline engines, so that difference in engine speed changes the way the ZDDP needs to activate to provide anti-wear protection. To get a little technical, diesel engine oils typically contain primary ZDDP and gasoline engine oils contain a blend of secondary and primary ZDDP. Just as a side note, racing oils just contain secondary ZDDP. Both types of ZDDP offer anti-wear protection, but the gasoline type of ZDDP provides more protection for higher-speed engines (think bigger valvesprings).

And it's not just the difference in the kind and amount of ZDDP, it's also the amount of anti-foaming agents. The needs are different between gas and diesel.

And beyond that, there is a difference in the amount of detergent and dispersants between gas and diesel.

It's a quick easy read with a lot of good info.

[Tom Vaught]

Always smile at these Hot Rod car type Magazine experts opinions.

15 years isn't chit in doing the job in oil research.

I was told 20 years ago by the BP Oil company (Oil EXPERT) who supported us at
Ford Research that the 15/40 oils would be just fine with my GTO when running a flat tappet camshaft. I haven't had one issue in 20 years of using the oil. 1350 PPM of Zinc.

So do I believe a Magazine Writer who writes for a car magazine or a expert with 30+
years of oil knowledge at the times whose company actually make oil products.

I will stick with what I have for the last 20 years. I bought the oil from a third party supplier Farm Fleet. Diesel engines love the stuff and the engines see very high crank loading.

Tom V.

We will not talk today about the fuels and lubricants classes I have taken in the past.

[ZeGermanHam]

Thanks for posting. Being a thread on the topic of motor oil, I'm sure it will bring about a spirited discussion. I recently bought about 3 oil changes worth of Lucas Hot Rod & Classic w/ZDDP oil for my '66.

[Sirrotica]

So I read the short article link posted, good information, especially about talking to a oil tech about what you have, and what they recommend to use after you give them the parameters of your combination, and usage of the engine, and conditions of the usage. Since I used to have a Pennzoil service station, I have found it invaluable to call their tech line to see what their recommendation is when I'm having a lubrication problem, or a recommendation.

I always run diesel oil in my diesels, and gasoline oil in my gas vehicles. There is a reason the oil companies offer oils for each type of engine, and fuel types. There is also a reason that the manufacturers specify what types of oil to use in their products.

The most important thing is to keep the oil clean, which I have thoroughly covered on this forum. The cleanliness of the oil will extend engine life, and minimize wear more so, than what brand, and type of oil that you're using. Yep, by pass filters.

I've posted before that too much ZDDP, can be as harmful as not enough, but I don't know if anyone has followed up. Most people think more is better, and too much is just right, that however isn't how it works in reality.

No matter which engine I have, I also use whatever full synthetic oil I can get for the usage of the engine I'm servicing. Nothing gasoline engine have is under 140,000 miles, The wife's car is the highest milage with 325,000 on it, bought the car brand new in 2008, the engine is all original. She is currently in Alabama because her father just had open heart surgery, and will be returning back to Ohio at the end of the week about 1600 miles round trip.

My trucks are all between 200,000 and 300,000 miles, I must have found an oil and filter program that works pretty well, to get engine longevity like that.

[PunchT37]

I could see crotch rocket oil vs...


But, a Pontiac v8?

[Tom Vaught]

In 20 years I have never had ONE FAILURE using that 15W40 "diesel" oil and my Solid Flat Tappet camshafts always looked like they were brand new when I did stuff where the intake and valley pan was removed.

But do whatever you want, IT IS YOUR ENGINE!!!

Tom V.

[Jay S]

I read through it. It kind of crack me up. Most my Diesels run more RPM’s continuously than most of my gas engines… Hmm???….Most diesel oil is not that high on zinc, maybe an average of 600-900 these days. That is high compared to what, an oil that will wipe a flat tappet cam before the next oil change?

Is there someone somewhere running diesel oil in their new direct injected gasoline engine causing preignition?

[Tom Vaught]

Very good question Jay.

Tom V.

[Schurkey]

Define "Diesel oil'.

Most of the so-called "Diesel oils" I've seen carry dual certification--Compression ignition (diesel) and Spark ignition (gasoline). That said, I can see that a product formulated for low rpm may not be optimum for an engine typically running a different fuel--and fueling strategy--at higher RPM.

Example:
https://rotella.shell.com/en_us/prod...dHRlci9lbl91cw
"Shell Rotella® T6 Multi-Vehicle 5W-30 is able to meet both API CK-4 and SN performance standards." (My emphasis.)

Lake Speed, Jr. is not a "Hot Rod car type Magazine expert"; he's got actual credentials in lubrication engineering, and an extensive background in racing/high performance if for no other reason than his dad, Lake Speed (Sr.?) was a big deal in Karting and NASCAR before it became NAPCAR. Jr. used to be with Driven Oil, now with Total Seal piston rings. I do not immediately discount his expertise even if none of the engines I build are radical enough to need specialized oil.

I maintain that the primary reason for all the crying over "ZDDP" was actually an excuse to deny warranty claims by cam/lifter suppliers who switched from quality lifters to cheap-junk imported lifters. Rather than acknowledge that they were selling crappy Chinese lifters with soft bottoms, they blamed the EPA for reducing ZDDP levels in motor oil as it poisons the catalytic converter over time (and especially with heavy oil burning!) Magazines picked up on this, and the whole ZDDP scare became full-blown.

It also created the market for "Hot Roddy high-ZDDP" and "Break-In" oils that gave Driven and various others a reason for existence. Big-name-brand oil companies were already selling "race" oils, but they weren't smart enough to create a demand for "break-in" oil. To paraphrase Jr., we all know that freshly-built engines need to "break in", and that a fair amount of wear occurs during this "breaking-in". The final "honing fluid" your engine sees is the "break in" oil. Break-in oil is formulated for just that purpose.

Lake Speed Jr. via Total Seal and Rottler has numerous Youtube videos on cylinder honing/ring seating/break-in; they're probably not applicable for the few engines coming out of my home-shop, but they're entertaining and a peek at the state-of-the-art for racing.

[TCSGTO]

Lake Speed Jr educational background is in business and marketing FWIW

[The Champ]

Originally Posted by Tom Vaught

Always smile at these Hot Rod car type Magazine experts opinions.

15 years isn't chit in doing the job in oil research.

I was told 20 years ago by the BP Oil company (Oil EXPERT) who supported us at
Ford Research that the 15/40 oils would be just fine with my GTO when running a flat tappet camshaft. I haven't had one issue in 20 years of using the oil. 1350 PPM of Zinc.

So do I believe a Magazine Writer who writes for a car magazine or a expert with 30+
years of oil knowledge at the times whose company actually make oil products.

I will stick with what I have for the last 20 years. I bought the oil from a third party supplier Farm Fleet. Diesel engines love the stuff and the engines see very high crank loading.

Tom V.

We will not talk today about the fuels and lubricants classes I have taken in the past.

Tom

Your career as an engineer for FoMoCo lasted many years. When you hit 15 years with them, were you knowledgeable in your field? Were you considered an expert in certain areas? I'm sure you were, and deserved the recognition.

As to advice given to you 20 years ago - has technology change in 20 years? Most assuredly yes as change is a constant.

The article was not written by a "magazine writer" as you claim, it was written by a "certified lubrication expert" for a magazine. Facts matter.

[Formulajones]

Lack of proper detergents is why I got away from desiel oils in a gas engine decades ago. Same reason I stopped using the Valvoline racing oils too.
Oils like that need more frequent change intervals. I sure hope guys using it are not trying to extend change intervals. Nevermind zddp, people forget about the rest of the additive package.

Speaking of which, how many here actually send in used oil samples for an oil analysis to actually know for sure what that oil is doing for you??

[Jay S]

I don’t know of any method better than sending the oil off for an oil analysis when your concerned about it doing it’s job.

We test oil when nessarry. Not every time. I think it is a good practice. Some of our equipment and vehicles have a gazzillion hours or miles on it, I know it is shot, and don’t an oil analysis to reaffirm that.

My concern with oils is always when new oil formulation gets changed to create a new issue. When Diesels oils started getting formulated for teir4 emissions equipment there started to be a lot of reformulations in oils used for Diesels. Finding a good mix of detergents and wear additive packages generally there seem to be trade offs. The oil analysis will tell you if you picked the right trade offs, and how long the oil change intervals are, plus if it is doing it’s job. Only problem is if you pick poorly on oil you may not make it to that oil change analysis with flat tappet stuff right now.

[Tom Vaught]

Originally Posted by The Champ

Tom

Your career as an engineer for FoMoCo lasted many years. When you hit 15 years with them, were you knowledgeable in your field? Were you considered an expert in certain areas? I'm sure you were, and deserved the recognition.

As to advice given to you 20 years ago - has technology change in 20 years? Most assuredly yes as change is a constant.

The article was not written by a "magazine writer" as you claim, it was written by a "certified lubrication expert" for a magazine. Facts matter.

Good Question: I put in 7 years in Emissions and F.E. and by the 7th year I was representing the Company in ALL Emissions actual testing at the EPA in
Ann Arbor Michigan.

I put in 8 Years, after that, working for Truck Operations and was the "go to guy" for and Emissions & F.E. testing as related to Truck Vehicles. Both Track Testing and Dyno Cert Testing. I hired in as a Pay Grade 6 (most hired in as a Pay Grade 5 and by 15 years was the highest pay grade (8) that a normal Engineer achieves (without going to management) vs engineering.

So 15 years experience plus my Holley Experience, I was the "Go-To Guy.

Mind you 39 years is a long time to work for one company.

A Certified person just means they can sign off on some testing, It does not
mean that they are are an EXPERT in the subject. Most in a field have to be
"certified" to observe given testing as a Witness. Nothing more.

So #1 .... 15 years you can be considered to be an expert in a given field.

#2 Certified just means you can sign documents which I did for my company
when we tested at the EPA.

#3 As far as advice, we are talking about an engine that has not been sold in many years (Pontiac). I wanted a durable 455 engine for my 64 GTO.
The BP Oil Technical Specialist gave me the info for that engine and its parts.

#4 As TCSGTO mentioned Lake Speed Jr's educational background is in business and marketing...

My advisor at BP WAS an Certified Engineer, A Big 3 Engineering Representative working in Research, not writing magazine articles.

Hope this helps you out on the DIFFERENCE in the two occupations and education required. If I needed a article written I would probably listen to him.

Tom V.

[track73]

I worked at Chevron gas station when my last 2 years of college. I bought Chevron DELO for $8 dollars a case of 24. I changed oil and filter every 2 months on my 67 Catalina. I had that car for 12 years and you could eat off the inside of the valve cover.

[Formulajones]

Originally Posted by Jay S

I don’t know of any method better than sending the oil off for an oil analysis when your concerned about it doing it’s job.

We test oil when nessarry. Not every time. I think it is a good practice. Some of our equipment and vehicles have a gazzillion hours or miles on it, I know it is shot, and don’t an oil analysis to reaffirm that.

My concern with oils is always when new oil formulation gets changed to create a new issue. When Diesels oils started getting formulated for teir4 emissions equipment there started to be a lot of reformulations in oils used for Diesels. Finding a good mix of detergents and wear additive packages generally there seem to be trade offs. The oil analysis will tell you if you picked the right trade offs, and how long the oil change intervals are, plus if it is doing it’s job. Only problem is if you pick poorly on oil you may not make it to that oil change analysis with flat tappet stuff right now.

Yes oil formulations changing has been going on for a long time and is hard to keep up with. Filter quality has as well.

Your last sentence is what I ran into years ago using Valvoline race oil. I was doing the typical 3000 mile intervals that was always preached at the time, and when I learned about oil analysis to my surprise I also found out that oil wasn't doing the job at those intervals. Rather than find out what that interval was I decided to change up the oil program and find something that worked as intended and lasted a decent oil change interval without harm.

I suspect with frequent oil changes these oils would work okay but I just have too many cars for that type of regimen.

As you stated once you find an oil and filter that suits your needs and is doing it's job, there really is no need for oil analysis after that. I can only think of two reasons you'd want to. One, if you suspect a problem and want to narrow down the root cause. Two, you've changed your routine, or your oil or filter brands and need to make sure it's still doing as intended. Otherwise it's not a necessary process that you have to spend a bunch of money on.
On that note, I haven't done it in years simply because I found what is working for me and haven't changed my routine since, nor had any type of issue.

[kingbuzzo]

give me that wonderful stuff...

[Tom Vaught]

Originally Posted by Formulajones

Your last sentence is what I ran into years ago using Valvoline race oil. I was doing the typical 3000 mile intervals that was always preached at the time, and when I learned about oil analysis to my surprise I also found out that oil wasn't doing the job at those intervals. Rather than find out what that interval was I decided to change up the oil program and find something that worked as intended and lasted a decent oil change interval without harm.


As you stated once you find an oil and filter that suits your needs and is doing it's job, there really is no need for oil analysis after that. I can only think of two reasons you'd want to. One, if you suspect a problem and want to narrow down the root cause. Two, you've changed your routine, or your oil or filter brands and need to make sure it's still doing as intended. Otherwise it's not a necessary process that you have to spend a bunch of money on.
On that note, I haven't done it in years simply because I found what is working for me and haven't changed my routine since, nor had any type of issue.

A lot of good advice there vs opinions from a a magazine guy.

I will stick with what I have been doing for many years, Oil designed for flat tappet camshafts and the valvetrain loads MY engine sees.
I do stuff for a reason.

(No issues in 30+ years.)

Tom V.

[Shiny]

I read the article and found it interesting but less than definitive. Anytime I see something complex simplified to that level, I tend to be skeptical.

In the article, the conclusions about "primary vs secondary ZDDP" was an example of something I wasn't aware of. Being ignorant, I decided to dig one layer deeper on just that topic. As expected, I think the real answer is "it depends".. Here is an interesting discussion with a lot of insight into the reality of ZDDP types and tradeoffs with other additives:

https://bobistheoilguy.com/forums/th...y-zddp.295359/

It's not simple enough to make a broad sweep IMO.

[geeteeohguy]

Originally Posted by track73

I worked at Chevron gas station when my last 2 years of college. I bought Chevron DELO for $8 dollars a case of 24. I changed oil and filter every 2 months on my 67 Catalina. I had that car for 12 years and you could eat off the inside of the valve cover.

I've been running Rotella or Delo in my flat tappet cars since 2002. Many tens of thousands of miles. When I pulled the engine in my '67 GTO in 2011 after a decade of using Rotella to install a rear main seal and replace the core plugs, the inside of the engine looked like new. Bearings showed no visible wear. Engine had 80,000+ miles on it since I last rebuilt it. Ten years later, still uses no oil, leaks no oil, and runs great. Same with the '65 GTO, '61 Corvette, and '83 Toyota 4x4. Decades of use and tens of thousands of miles of trouble-free service and counting.