T6 bad for catalytic converts

[mechanicx]

I agree. The SM rating is probably not a factor regarding cat conv protection and recommendations. It's that T6 while SM rated, being a 40 grade HD oil is not an ILSAC GF4 oil. I think the ILSAC rating has more to do with gasoline engine cat conv protection than the API service rating, right?

Anyway like you said, his vehicle did not originally require SM or even GF4, but probably GF2 or 3.

 

[Ken2]

Keep in mind the difference between API Service Categories and ILSAC GF-5 specs. It is GF-5 (and GF-4 before) that set the low phosphorus levels for the long life of the catcon. API SM and SN have higher allowable PH levels.

 

[edhackett]

Any vehicle before 2004 would have been running SL or older which had P-Zn levels roughly the same as current CJ-4 HDEOs. Converters didn't drop dead left and right then, they won't now.

Ed

 

[Garak]

Originally Posted By: dnewton3
I'd email them back and ask why it would be detrimental for a cat in a gasser, but it's "recommended" for a diesel engine, all of which today also come with cats ...


Absolutely. After all, SM is a modern gas spec, which came about long after the introduction of cats. And the PCMOs contemporary to the vehicle in question had similar ZDDP levels.

 

[rslifkin]

Originally Posted By: southernjeeper
So is the new formula of T6 is perfectly fine with gas engines then????

I just had found when I google'd that t6 might be bad for cat converters hence why I emailed SHELL from their site.




SO when it all boils down to is there is no harm to shorting out the life of a catalytic converter? correct?


I should have mentioned that I switched from castrol 10w30 to the T6 in just the TACOMA not the jeep yet. I am going to see about a good 4,000 or 5,000OCI on the truck.

As for the cherokee I will switch sometime this fall due to me driving the tacoma a lot more nowadays.

thanks for all the responses. I know I can trust a bunch of feedback on here than anywhere else.


As long as you're not burning a ton of oil (which will kill the cat regardless), it won't hurt anything. I'd be a bit more hesitant to run it in something brand new and designed around lower ZDDP oils, but it certainly won't hurt a YJ.

I've been running T6 in my ZJ since shortly after I got it, so that's 19k miles on T6 before I did the heads/cam/exhaust, etc, and almost 17k miles since then (burned about a 1/2 quart in 6k before the work, about an 1/8 of a quart in 6k since then). My mom's 99 4.0 WJ has had T6 in it for a solid 15k miles with no issues (doesn't burn a drop of oil, one of the least clattery 4.0s I've heard).

 

[beanoil]

Originally Posted By: tommygunn
Sounds like you got a secretary who fields emails with an automated database.

This. Over 200k on a 95 Merc Villager on Rotella 10w30 proves otherwise. The ratings are on the bottle, and mixed fleet is just that... gas and diesel fueled vehicles. Maybe whoever sent that reply would like to share some of the product they are smoking.

 

[Hessam]

I have been using Delo Syntethic, or T6 in my 96 landcruiser for about 200K now....I did have to replace one of the O2 sensors, and both the cats after about 197K on the clock, but that's more a result of old age and lots of miles, than the HDEO oil.

since i installed the new cats (ATE), I have been getting wierd cat alarms every 15K or so....when I clear the alarm, cats are fine, and then about 15K or more I get the cat alarm again (it's actually a check engine alarm, but the check engine code points to the cats being faulty...but I have taken the cat off and don't see any signs of premature wear, or excessive clogging etc....

I think HDEO's being rough on cats is more of a urban myth than anything else.

 

[LeakySeals]

Originally Posted By: Hessam
I have been using Delo Syntethic, or T6 in my 96 landcruiser for about 200K now....I did have to replace one of the O2 sensors, and both the cats after about 197K on the clock, but that's more a result of old age and lots of miles, than the HDEO oil.

since i installed the new cats (ATE), I have been getting wierd cat alarms every 15K or so....when I clear the alarm, cats are fine, and then about 15K or more I get the cat alarm again (it's actually a check engine alarm, but the check engine code points to the cats being faulty...but I have taken the cat off and don't see any signs of premature wear, or excessive clogging etc....

I think HDEO's being rough on cats is more of a urban myth than anything else.


What make of cats were they? Some aftermarket cats on the market have insufficient catalyst media compared to OE, and that could cause a P0420/30 catalyst efficiency CEL code. Toyotas are picky like that. Its the ECU programming - very strict. There is another trick to shut that off tho.

 

[Lead Shoes]

The OEM cat on my Honda survived a quart per 1k for probably the later half of its life, most of it HDEO by the previous owner, and it never threw any codes for the cat.

 

[HerrStig]

I thought the latest T6 was SM. Not going to hurt a cat on a vehicle from pre SM grade days. Of course if you start using it in an older car with 200K already on the cat, you might blame it for the falure which would happen ANYWAY in time.

 

[Volvohead]

Originally Posted By: southernjeeper
"We do not recommend Rotella T6 for engines with catalytic converters."


Might have been said, but I don't believe a word of it.

More RTS for me for anyone who does.

 

[440Magnum]

Originally Posted By: tommygunn
Sounds like you got a secretary who fields emails with an automated database.


+1

Its SM rated, you can safely run it in gasoline engines. Its got no more ZDDP than the oils that were shipped in older gasoline engines from the factory (and by "older" I mean as little as 10-12 years, not 30 years ago.)