Best D.I. oil for Caddy CTS?

[johnachak]

Hi all, Thanks for any input you may have.
I have a 2009 Caddy CTS with the 3.6 DI engine. The oil cap calls for mobil 1 and the Caddillac manual calls for the Corvette Spec. oil. I have heard of timing chain failures on these engines if using the extended OCI called for in the OLM (Up to 12,000-1 year).
Is Mobil 1 really the best for this type of engine or would something like Pennziol Ultra or Kendall GT1 Ultimate Synthetic be better? I currently do my changes at 6 months which could be anywhere from 2000, to 6000 miles. Overkill I know, but as for these engines, I don't like what I've read. I love it and I intend to keep it.

 

[johnachak]

Sorry typo, hit the wrong button, submit rather than review... Should have been:
Is Mobil 1 really the best OIL for this type of engine?
AND
Pennzoil Ultra
Thanks again

 

[demarpaint]

Of those choices I'd use PU, ignore the OLM and change the oil at about 4000 miles. The GM DI engines are beating up even the very best boutique oils, so I'd play it safe than sorry.

Having said that I would run 2 4000 mile OCI with the brand of oil you pick, and at the second OCI get a lab report. Then have a look at the viscosity of the oil and the fuel dilution, post the report here. Once you have the data we can tell what the best OCI would be for the car.

You could also take a sample after the first run with the assumption that there will be residual oil from the prior run, and your engine is still breaking in, but at least you'll know where you stand with fuel dilution. Now if you have at least 20K on the engine break in will be less of an issue, but still going on. The main thing I'd be conserned with at this point is dilution and viscosity. JMO

 

[The motor guy]

why do I keep hearing that these direct injection engines are hard on oil as far as fuel dillution? You'd think it would be better about fuel in the oil since they are more precise at delivering the fuel. If it's still under warranty i would just keep using the factory spec oil that way that can't say well you didn't use mobil 1.

 

[demarpaint]

Read the UOA section here on Bitog and search the www. DI engines are getting a bad rap for beating up even the best of oils. IMO the OLM will have to be reprogrammed and intervals shortened until they address the problems with many of them.

 

[Eddie]

I run PP in my Mazda CX7 (DI with turbo) and do 6,000 mile OCs. I have several UOAs during the 44,000 miles and while fuel dilution is ~ 0.4% the UOA are very good. NOT ALL DI engines are affected and I supposedly have one of the worst. My advice is use what the oil the factory recommends AND use the OLM (change at 40-50%) and after the second oil change, have a UOA preformed and adjust from there.

 

[dave1251]

Do not all DI engines do this. It is GM's 3.6. For your warrenty proposes you have to use a synthetic. If you can get PU or Kendall for a better price over Mobil one go ahead and use it.

 

[Durango]

johnachak,

My brothers GM dealership uses Castrol "Syntec" in place of Mobil 1. They told him it's just as good.

Durango

 

[21Rouge]

Originally Posted By: johnachak

Is Mobil 1 really the best for this type of engine


No. At this point I suspect that an HDEO will provide the best protection for this fuel diluting DI engine. However such an oil is not warranty approved.

 

[johnachak]

First, Thank you for all the help everyone. This change (The dealer said to go 5 months to be on the "Safe side" I agreed to 6 months as Long as the mileage is low. This change is really low mileage but is pushing the 6 months. Probably only 1,200 miles or so. The summer is when we ring up over 4000 (Road car ). I guess I'll do a U.O.A. after the 4000 mile one on the M1 and see if that was pushing it or not. I think this 1,200- 1,300 mile one would be a waste of a $24.00 U.O.A.
Sounds acceptable (Using all the posts) I hope.

 

[shpankey]

Not in warranty, but Red Line is the oil I've seen do the best in DI engines with fuel issues. Look for posts by saaber1 and read as many of them as you can.

If you're fortunate enough to have another car that you can buy the M1 for, you could feasibly use those receipts for your car while you actually use something like Red Line 5w40, which is a very proven oil for heavy fuel dilution. It hardly uses any VII's so it's very shear proof.

Also, it seems to me some cars are worse than others, even of the exact same car. See the Mazdaspeed 3 UOA here with Amsoil. That particular car seems to have more of an issue than others of the same type (I have the same car without the heavy fuel dilution he does). So a UOA of your car would be wise.

 

[edhackett]

As stated, HDEO's are able to stand up to fuel dilution better than most oils, even most synthetics. The Rotella line from Shell is one of the better ones.

Mobil 1 has been shown to not stand up to fuel dilution well at all. I'd switch to PU and see how that does, if under warranty.

Ed

 

[johnachak]

Sure is under warranty. 3 years left on the 5 100,000 and I extended it to 7 years. Thats why i only mentioned oils with the 4718 spec.

 

[Old Mustang Guy]

My wife's Acadia has the 3.6 DI but it does not spec full syn. Right now I've got PP in it which is of course 4718M. I'm doing 5k OCI's just to be safe. Ironically, I remember one UOA on this engine that did not show high fuel. I think perhaps we fret too much about the DI, or at least that is what I choose to believe until I get a UOA. In your case, I would say use any good syn that has the right approval. I bought QSUD for next time because it is the best value out there right now.

 

[tig1]

M1 stands up very well to fuel dilution, or as well as any oil can. Just stick with an oil that meets your spec.