HDEOs in Gasoline Engines and Cats

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I have heard that using an HDEO in a gas engine will cause harm to the cat but I have heard of people using them no such effect. So then I was thinking today that most of the HDEOs are rated SL or SM meaning they are safe to run in gasoline engines. Could they really get an API gasoline rating if they actually caused harm to the emission system of a vehicle? Just curious.
 
We ran Castrol Rx Super 15w40 in many petrol powered cars and never had any problem.Never set any trouble codes in emission system related components.
We have done this for many many years.....
 
I've ran several brands of 15w40 hdeo's in my old gallant. While it doesn't have a Cat monitor O2. I believe it to still function. Its for sure not stopped up and still gets HOT within a few min of startup, so I think its not hurt. It does burn a bit of oil but only about 1/2 Qt every 1500 miles or so. Perhaps not all of that is burned though as the head shows some sign of seeping. Definitely not enough to warrant pulling the top end down and replacing the head gasket. I never notice a drip anywhere I park. I basically think any oil will kill your cat if your burning excessive amounts though one high in zddp or certain other additives may be worse.
 
By definition an HDEO is dual rated. You are thinking of Diesel oils. Two different animals.

A highly additized old school HDEO will have a lot of P. In theory, this oil, in an oil burner (or hot engine and lousy NOACK oil) could contaminate a cat by bonding to the Pt/Pd surfaces.

OTOH I would not hesitate to run a CJ-4 oil in even the newest modern engine.
 
Originally Posted By: Pablo
By definition an HDEO is dual rated. You are thinking of Diesel oils. Two different animals.


So then what would be an example of a diesel oil? I always think of the big three in my mind: Delo, Delvac, and Rotella. All three of those carry CJ-4 ratings but carry SL or SM ratings as well.
 
I've used HDEOs (Rotella 5W-40, Rotella 10w30, Tection 15w40)
in a couple of gas OBDII engines, and have never seen any codes thrown as a result.
I figure that if the oil is rated SL or SM, it should be okay to use.
 
No gasoline rating; if you read the specs you'll note it's rated E4/B2 but has no A rating. I specifically used it as an example of a diesel only oil. And it is only for European mfg'd larger truck diesels, with either no EGR or low EGR rates. I would not put it in any American made diesel except a Mack that calls for EO-M.
Someone asked "So what would be an example of a diesel only oil?"

Charlie
 
i have a c1500 WT with a 4.3 in it that has had mostly 15w40 in it since it was new in 93. I would probably say at least 70 percent of its life it has had 15w40 in it. Half of its life it spent in PA even in the winter. This was the old 15w40 that was CI rated. Truck still runs pretty good and has 215k miles on it. Im not saying this was a good idea im just saying you can run CI or CJ oils in most gassers without a problem. Use some sence, if you live in canada and make nothing but short trips or dont do anything to warrant the use of a HDEO, dont use it it is unnecessary most of the time. My father in law refuses to use anything but rotella 15w40 in his stuff. He lives in PA and most of the stuff he uses it in are small american cars ie. cavalers ect. I cant change his mind and it seems to be working for him it just seems silly to me.
 
Originally Posted By: jstutz
My father in law refuses to use anything but rotella 15w40 in his stuff. He lives in PA and most of the stuff he uses it in are small american cars ie. cavalers ect. I cant change his mind and it seems to be working for him it just seems silly to me.


I can't say I blame him. The stuff is packed full of additives and only cost $2.75/qt where I live. Very stout oil at a very skinny price.
 
Well I can't get that ACCCC web page to load. I would be interested in different grades but they seem hard to find. The xxW-40 HDEOs are everywhere though.
 
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