dual-rated (gas/diesel) oils

Joined
Nov 30, 2004
Messages
2,783
Location
SD
I belong to a group for old flathead engines. Many on the group like to use HDEOs in their engines. While I don't use them personally, I see the appeal, and understand that these oils will work just fine.

The problem is, there is a member who is a former automotive engineer. While knowledgeable about the engines, he is a chicken little kind of guy about oil. He emphatically warns members that "diesel oil" will damage their engines. Unfortunately, many believe his scare tactics.

I have posted links to PDSs which show that most of these oils also carry a gasoline engine (S) rating, but he continues in his quest to spread his ignorance. Does anyone have a link that I can share with the group that explains that dual-rated oils are fine for gasoline engines? I'm looking for something authoritative, such as something from the PQIA, for example.

I couldn't care less about winning an argument with some foolish keyboard commando, but I would like to be able to assure other members that their oil choice of Rotella, etc. is not harmful to their classic car.

Thanks in advance!
 

zrxkawboy

Thread starter
Joined
Nov 30, 2004
Messages
2,783
Location
SD
Yikes, some folks didn't read my post too closely! Not looking for examples of these oils, and not looking to argue with the fool I mentioned. I'm simply trying to help folks learn. Isn't that the point of groups, to come together and help each other learn?
 

SR5

Joined
Jul 7, 2015
Messages
6,537
Location
Down Under
Mixed Fleet (gasoline/petrol & diesel) engine oils have been used successfully for many years. Now Valvoline has developed an oil for natural gas(LPG) and gasoline/petrol and diesel engines.




 
Joined
Aug 7, 2018
Messages
122
Location
WI
Diesel oil will not harm a gas engine provided that something crazy like 15w-40 isnt run in an engine calling for 0w-16 in -20F weather. All the warnings against using non-dual rated diesel oil in a gas engine are for the risk of damaging the catalyst. Even then, unless it's a major oil burner, I can't see how that is going to happen. I run Rotella T4, T5, T6 in my grand caravan (in my sig) without losing any sleep. IT seems to love it.

It's someone who doesn't really understand what is going on using scaremongering to get people to listen to him. Am I an oil expret? Not by a long shot. However, I feel I do understand it well enough to be able to say this.

Many around here know more about it than I do. If I am wrong, please correct me and do so kindly.
 
Joined
Jan 2, 2004
Messages
9,601
Location
California
Diesel oil will not harm a gas engine provided that something crazy like 15w-40 isnt run in an engine calling for 0w-16 in -20F weather. All the warnings against using non-dual rated diesel oil in a gas engine are for the risk of damaging the catalyst. Even then, unless it's a major oil burner, I can't see how that is going to happen. I run Rotella T4, T5, T6 in my grand caravan (in my sig) without losing any sleep. IT seems to love it.
Even Toyota says 20W-50 is a-OK in Australia and Southeast Asia with their new Dynamic Force engines that while designed around 0W-16/20 is a “global” engine. Even enough API SM/SN/SP and D1 oils are supposed to “help” with cat poisoning due to a engine burning oil, P0420s from a poisoned cat due to burning oil is still a thing.

API CF-2/CK-4/FA-4 and ACEA E7/E9 have lower SAPS for preventing a DPF/SCR from getting plugged. But EGR is another thing.
 
Joined
Jan 25, 2003
Messages
5,354
Location
Decatur AL USA
I belong to a group for old flathead engines. Many on the group like to use HDEOs in their engines. While I don't use them personally, I see the appeal, and understand that these oils will work just fine.

The problem is, there is a member who is a former automotive engineer. While knowledgeable about the engines, he is a chicken little kind of guy about oil. He emphatically warns members that "diesel oil" will damage their engines. Unfortunately, many believe his scare tactics.

I have posted links to PDSs which show that most of these oils also carry a gasoline engine (S) rating, but he continues in his quest to spread his ignorance. Does anyone have a link that I can share with the group that explains that dual-rated oils are fine for gasoline engines? I'm looking for something authoritative, such as something from the PQIA, for example.

I couldn't care less about winning an argument with some foolish keyboard commando, but I would like to be able to assure other members that their oil choice of Rotella, etc. is not harmful to their classic car.

Thanks in advance!

ZDDP wasn't invented until 1941. I suspect moat flathead automotive emfines were designed before it became ubiquitous. In otherwords while I understand your frustration the engine would likely be happy with most anything on the shelf.
 
Joined
Jul 25, 2021
Messages
36
I belong to a group for old flathead engines. Many on the group like to use HDEOs in their engines. While I don't use them personally, I see the appeal, and understand that these oils will work just fine.

The problem is, there is a member who is a former automotive engineer. While knowledgeable about the engines, he is a chicken little kind of guy about oil. He emphatically warns members that "diesel oil" will damage their engines. Unfortunately, many believe his scare tactics.

I have posted links to PDSs which show that most of these oils also carry a gasoline engine (S) rating, but he continues in his quest to spread his ignorance. Does anyone have a link that I can share with the group that explains that dual-rated oils are fine for gasoline engines? I'm looking for something authoritative, such as something from the PQIA, for example.

I couldn't care less about winning an argument with some foolish keyboard commando, but I would like to be able to assure other members that their oil choice of Rotella, etc. is not harmful to their classic car.

Thanks in advance!
If your friend can read, perhaps the attached PDF will convince him.
I belong to a group for old flathead engines. Many on the group like to use HDEOs in their engines. While I don't use them personally, I see the appeal, and understand that these oils will work just fine.

The problem is, there is a member who is a former automotive engineer. While knowledgeable about the engines, he is a chicken little kind of guy about oil. He emphatically warns members that "diesel oil" will damage their engines. Unfortunately, many believe his scare tactics.

I have posted links to PDSs which show that most of these oils also carry a gasoline engine (S) rating, but he continues in his quest to spread his ignorance. Does anyone have a link that I can share with the group that explains that dual-rated oils are fine for gasoline engines? I'm looking for something authoritative, such as something from the PQIA, for example.

I couldn't care less about winning an argument with some foolish keyboard commando, but I would like to be able to assure other members that their oil choice of Rotella, etc. is not harmful to their classic car.

Thanks in advance!
Tell him to Google this and read fully the PDF.
2016 ACEA European Oil Sequences
ACEA EUROPEAN OIL SEQUENCES

FOR LIGHT-DUTY ENGINES

2021

SERVICE FILL ENGINE OILS for GASOLINE & LIGHT-DUTY DIESEL ENGINES (A/B Categories),

GASOLINE & LIGHT-DUTY DIESEL ENGINES

with EXHAUST AFTERTREATMENT DEVICES (C Categories)
 
Top