Diesel motor oil in gas engines?

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Originally Posted By: 03Marauder
Are you guys using diesel motor oils in your gasoline engines? If so, why?


A few years ago I used Amsoil's premier diesel oil in my gasoline engine. It worked very nicely. I have no idea what the difference is between gas and diesel oils.
 
I'm using Shell Rotella T 5w40 (diesel) oil in an '04 Mercedes gas engine.

Why? Because it is a good oil, it carries the API SL gas-engine rating, it is the viscosity specified by M-B for my car, and I can get it at a decent price.
 
In my limited knowledge... most diesel oils are usually only available in heavier weights, which may not be suitable to your engine. Example: manufacture spec calls for 5W-20. I believe I read once that diesel oils may clean gas engines a little to well, thus possibly causing some problems. Overall, you probably will cause no harm to your engine by running diesel oil.
 
I think diesel oils contain much higher levels of zinc and other additives which are bad for catalytic converters. Some oils are rated for gas or light duty diesel engine.
 
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Diesel oil will be fine if your OEM doesnt require ILSAC spec oil, or if you dont mind assuming some risk for your emissions system. As Im sure you could search on this site the reference material the Asian and US OEMs have speculated and supported though some degree of testing (though these tests have come back as being arguable negative as well) that ZDDP is harmful to the emissions system catalyst. Therefore, they began back in the lat 80s or early 90s (I think) via the ILSAC spec'g lower levels of ZDDP via the GF pronouncements. However, diesel and Euro apps are partial to the added wear protection from ZDDP and thus levels in diesel and non ILSAC spec oils remain higher. Additionally, but not detramentally, diesel oils typically have higher bases to permit longer drains from a longer time coping with conbustion by product acid and better insol seperation. It may be these properties that make have diesel oils known for cleaning gas engines. My understanding, though not so well spoken. Im an analyst, not an engineer.
 
I know I sound like a broken record but been running the Amsoil ACD diesel oil in the TL for the majority of it's life and no problems with emissions after 66,000 miles.
 
Ive used Chevron Delo 15w40 several times in my Bonneville (3800 V6) and was happy.

Originally used it for the first 4000 mile run after fixing an intake coolant leak(after the 500 mile "Purge" break in with cheap dino) I would be using it now as a summertime oil, but Im using up the Exxon Superflo.
 
It really isn't a diesel oil it is a Heavy Duty Engine Oil ,an oil made to withstand the most severe commercial use in gasoline and "high speed automotive type." diesel engines.
 
Originally Posted By: 03Marauder
If so, why?


Because folks used to say otr big rigs run a half a million miles between overhaul. And, "diesel oil" has more antiwear, antioxidant, and detergent additive than gasoline engine oils have. And, it's cheaper than Mobil 1.
 
I ran Amsoil HDEO 5W30 in the Taco when i moved from California to Texas three years ago. 1500 miles and towing almost 4000 lbs the oil color hadnt changed...dont know if thats good or bad or not but to me it held up great.
 
running Rotella 10w30 HDEO in my 98 Explorer 5.0 liter.

picked up several gallons for 7 bucks each at walmart when they clearanced it out.


why do i run it?

because i can :)
 
With four vehicles, two tractors, two generators, and other odds and ends, I'm moving to using HDEOs in everything just to simplify my inventory of motor oils. Right now my applications and oils are:

--'87 Ferrari, Shell RTS 5W-40
--'71 Alfa Romeo, Shell RTS 5W-40
--'06 Nissan, Formula Shell 5W-30, planning Shell RT 10W-30
--'04 VW TDI, Castrol TXT 505.01 5W-40, planning Valvoline Maxlife Synthetic 5W-30
--'04 John Deere 4610, Chevron Delo 15W-40
--'08 John Deere 2305, Shell RT 10W-30
--'01 Northern Lights 10 HP diesel generator, Castrol Tection 15W-40, planning Chevron Delo 15W-40
--'02 Generac 14 HP gasoline generator, Chevron Supreme SAE 30, planning Shell RT 10W-30.

Ironically I'll be using PCMO for the diesel VW Jetta as that is what the OM calls for specifically
 
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