Safe to use Rotella T in gas motor

[wickerham]

I emailed Shell about using Rotella T 5w-40 in a gasoline engine.
Yes, I know it has the SM cert. but I also know it's high ZDDP can wreck a cat or two. So, with all this in mind, I shot them an email. The following is their response:



Mr. Wickerham,

Rotella T 5w-40 meets both the API CJ-4 and SM specifications. It can therefore be used in Gasoline as well as diesel engines.

We do not recommend for use in engines with catalytic converters that require ILSAC GF-4 specifications.

Best Regards,
Technical Service


So, my question is: How do I know if my cat requires ILSAC GF-4? I just bought and installed it over the summer and don't wanna kill it prematurely. It's a Carsound by Magnaflow.

 

[coffee]

NO!!!!...get it out of there NOW!!! It will destroy your Cadillac Converter!! Well, only if it is not already a Cadillac but better safe than sorry.

Just kidding man, it will not hurt anything and is used by a lot of gas cars. I have never heard of any issues with the converter going bad due to Rotella.

 

[Johnny]

I would be more concerned about using the right viscosity.

 

[Gary Allan]

Prematurely may mean the difference between your lifetime and the archeologists that find your car's remains after the next civilization emerges from our ruins.

That is, while higher phosphorus level does indeed fatigue the catalytic converter more than lower phosphorus levels, there's no index of how much it shortens the practical lifespan of the catalyst.

There's also the simple deal of how much total phosphorus you're introducing into the engine to ever reach the cat.

Think of it this way. Two identical engines ..dyno'd until cat failure. OEM service intervals (or any equal interval). The GF4 cat will probably last longer assuming it was from the same lot. We don't know if it will be 180k ..250k...300k....whatever ..and we don't know how much sooner efficiency thresholds will be reached.

Now move this to the REAL level ..and you can have one Joe sixpack changing it with low phos oils every 3k and have his neighbor with the same car using RTS for 6k and he's processing less phos through his engine than the low phos user.

This is a policy issue, imo. High phos oils have not produced any rash of cat failures over decades. Why would we expect it now given the variables involved? Now if one were to implement tighter on board diagnostic protocols for cat failure, then it may turn formerly functional cats into unacceptable cats on NEW(er) vehicles ..but, imo, that still doesn't mean that the 3k/3m low phos guy is doing his cat any favors over the RTS user assuming that the total phos processed through the engine is within a given equivalency.

 

[demarpaint]

Unfortunately the guy answering the phone or replying to the email has certain rules he has to follow because of legal issues. So he has to state use the oil spec'd for your engine, or lingo along those lines. Take that same question and ask him at a bar having a few drinks and he'll give you the answer you're looking for.

 

[hate2work]

Originally Posted By: demarpaint
Unfortunately the guy answering the phone or replying to the email has certain rules he has to follow because of legal issues. So he has to state use the oil spec'd for your engine, or lingo along those lines. Take that same question and ask him at a bar having a few drinks and he'll give you the answer you're looking for.


Exactly. There is an official answer, and there is the real answer.

And Gary, well said

 

[JHZR2]

Unless there is a warranty in question where a certain set of specs MUST be met, I'd use it. API SM means that it meets the latest specs, and is more benign on cats than older oils. Yes, SM for 40wt oils allows more Zinc than in 30wt oils, but it is still a good mix, and should not be an issue.

If you are truly consuming large amounts of oils you have other issues anyway...

 

[Quattro Pete]

Originally Posted By: JHZR2
If you are truly consuming large amounts of oils you have other issues anyway...

Our Jetta is notorious for consuming oil... about a quart every 3-4k miles. Not sure if this is considered "large amount" or not. So, is RTS a bad choice in this case?

I'm about to switch it to GC starting with next oil change anyway...

 

[Gary Allan]

I've never really seen someone consuming oil to have a cat go bad. In fact, every cat I've ever personally seen fail (I think it was 2) the engines were not anywhere near that level of consumption.

I doubt anyone else has either.

Again, how much is the difference between the total pounds process through the engine between one or the other?

1quart/4k isn't a lot of oil.

 

[joflewbyu2]

Originally Posted By: wickerham
So, my question is: How do I know if my cat requires ILSAC GF-4? I just bought and installed it over the summer and don't wanna kill it prematurely. It's a Carsound by Magnaflow.

According to this article, no. See the following:
http://www.zddplus.com/TechBrief6%20-%20...e%20Engines.pdf

I know HDEO have more detergents to clean diesel engines and their additives are specific for low RPM high load engines. Older diesel oils were popular because of the additives that they had while newer diesel oils have less of since diesel emissions passed for 07 model year. New diesel oil are safe for cats but do not have that good old additives they use to have.

 

[lipadj46]

They still have more additives and have a stouter base stock than regular PCMO's.

 

[ueberooo]

Originally Posted By: wickerham
Safe to use Rotella T in gas motor

If by safe you mean "the oil not catching on fire in the crank case, bursting into flames, and subsequently exploding the car and bringing fire and death to anyone and anyone in the immidiate vicinity" then no, hardly safe.

 

[vxcalais]

Look here, in Oz, some Ford BF 2006 utes, the exhaust snaps clean off at the cat. The cat mechinism fails, nothing to do with the oil hehe

 

[ueberooo]

Originally Posted By: vxcalais
Look here, in Oz, some Ford BF 2006 utes, the exhaust snaps clean off at the cat. The cat mechinism fails, nothing to do with the oil hehe

Tell that to our EPA. The cat could fail, as could any of the hundreds of components in a car (many of which are just as costly or more as a cat). Maybe the EPA should mandate that tire tread lasts a minimum of 100K miles under worst case conditions, and have a minimum tread rating of 5000.

 

[vxcalais]

Look here, in Oz, some Ford BF 2006 utes, the exhaust snaps clean off at the cat. The cat mechinism fails, nothing to do with the oil hehe

 

[Eddie]

Probably has more to do with engines that consume more oil than others. If my engine consumed 1 quart per 2,000 miles I'd be concerned a lot more than if my engine consumed on a 1/3 per 5,000 miles.

 

[wickerham]

It gets better guys, here's the reply from Magnaflow after I emailed them asking if my cat would be okay if I used RTS:

Hello,
Can you please provide me with more information about the
vehicle? If you could please provide the year, make and model of the
vehicle. I may be able to provide you with a more specific and detailed
answer. Thank you for contacting Magnaflow Exhaust.

Derek Acosta

Performance Sales Specialist

Magnaflow Performance Exhaust

Then my reply:

My vehicle is a 1993 Jeep Grand Cherokee 5.2L V8, I don't see what
difference the year, make and model would make, it's still magnaflow
part #94006. Regardless of make, model and year will high ZDDP oil
effect longevity of my cat?

And finally, his last reply:

Hello,
As of this point right now I could not tell you if the
aftermarket oil you are planning on using will damage the cat. I spoke
to my engineer and we have never tested anything like this before.
Please let me know if you have any additional questions. Thank you for
contacting Magnaflow.

Derek Acosta

Performance Sales Specialist

Magnaflow Performance Exhaust

I love "safe corporate answers" !!

 

[Drew2000]

I think bad coil packs or misfires damage WAAAY more cats on vehicles than moderate oil consumption of a higher phosphorus-containig oil.

 

[wickerham]

I agree, I'm just trying to get Magnaflow to say that it'll be fine so I'm still covered under warranty.