Diesel oil to clean petrol engine?

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I've heard of people saying to run diesel oil in a petrol engine to clean it out due to the extra cleaning properties in the diesel oil.

Is there truth to this?
Any disadvantages, or things to be careful of?
Recommended oils etc?
 
Actually I meant using oil designed to be used in diesel motors, not actual diesel fuel
 
Most HDEO's are rated for Gas or Diesel
If you don't mind 10w-30 or 15w-40 there are some very good HDEO's available.

I have used Rotella in my Triumph for years, My Toyota 22R also gets it in the summer.
 
Many diesel oils carry API SL/SM certifications, meaning they are safe for use in gasoline motors. I'm not sure they would clean any better than gasoline oils though.
 
Originally Posted By: Spetz
Actually I meant using oil designed to be used in diesel motors, not actual diesel fuel


Yes, Diesel oils have more detergents and dispersants than gas engine oils. I'm using some M1 TDT I got cheap at AZ to clean up my old Trans Am engine. Run it until it gets dark, dump it, new filter then repeat.
 
Originally Posted By: Spetz
I've heard of people saying to run diesel oil in a petrol engine to clean it out due to the extra cleaning properties in the diesel oil.

Is there truth to this?
Any disadvantages, or things to be careful of?
Recommended oils etc?


There may be some merit to this idea.
HDEOs often have an add pack rich in magnesium which may be a more efficient detergent/dispersant than the caclcium which is usually the dominant detergency add in PCMOs.
Magnesium also incidentally gives better TBN retention than calcium.
If I were going to try this approach, I'd look at formulation and select an oil with plenty of magnesium and calcium to maximize the cleaning potential.
Still, unless an engine has been badly negelected or has suffered something like coolant leaking into the oil, there isn't usually much to clean up.
 
Originally Posted By: Eddie
Not good for the cat converter because of increased zinc


If they meet "S" specs, then this isn't true...40s are allowed to have higher zinc, as less reaches the cat convertor through reduced consumption.

If 1qt of 20 or 30 per 1,000 miles passing through the cat is OK (as per OEMs), then any normal car with normal oil consumption, HDMO additive levels are no issue at all.
 
It works fine as cleaning oil...
It works fine as lubricating oil also...
And while it may not be the best for a catcon it wont killém either.
They have a tendency to turn black quickly if the engine isnt squeeky clean so dont change to soon.
 
For me, running Amsoil synthetic ACD 10W-30/SAE 30 diesel oil had a a more noticeable visual cleaning effect than Auto-RX.
 
From what i can see all oil for many years in Europe has been for both petrol and diesel engines.

You do get stuff like Maxlife Diesel or Mobil 1 0w40 Turbo Diesel but that is still rated for petrol engines.

The only difference i have noted between Mobil 1 0w40 Turbo Diesel and Mobil 1 0w40 New Life is that TD isn't approved to Porsche A40
 
The Canadian M1 0w-40 had the older CF rating until quite recently. Nonetheless, it's a very dated rating, and while there are a fair number of vehicles on the road that originally called for CF, those tend to be older Cummins and the like. Operators of those vehicles were using HDEOs all along and most never would have considered M1 0w-40 even as an option, given that it's not a traditional HDEO. Additionally, here it has to be bought in 1 L bottles, and that gets a little pricey with a 15 L sump.

I have no doubt that M1 0w-40 would still work in an older diesel engine calling for CF in a 40 grade (whereas plenty of current 10w-40 and 20w-50 PCMOs here might be questionable). It just would not be even remotely cost effective.
 
My uhaul mechanic was once an emissions tech, he said the go to way to totally clean out a motor that is neglected to no end was adding diesel fuel to the crank case for a short amount of time...

IM not going to tell what he did as a tech when a nasty varnished motor came in to prevent a fight on bitog.

He did however, buy an s10 with 24xxx miles on an oil change, the motor was disgusting on the inside. He drove it around with 3 quarts of 30wt and 2quarts of diesel for about 2000miles till the oil was black, he changed it out and ran the hdeo 1030 and the truck now has like 190k and it runs like a top... he claimed the hdeo didn't have much to clean afterwards, and the diesel was the go to thing for flushes.

The local autos teacher at my high school helped some of my friends do the ( 30 minute flushes )where you fill the crank case with diesel and let it run for a minute at a time. After 30 starts the fuel is black and the motor is spotless inside.

Many will disagree, I can only speak for what I've seen
 
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