Castrol Edge with Syntec

[Danh]

After a recent oil change I thought the oil level on my 2008 Mazda MX5 had risen about 1/4 quart. Being concerned that there was fuel or antifreeze contamination, I had the dealer take a look and they concluded all was well.

Not being absolutely confident in the dealer, I sent a Used oil sample to Blackstone even though the oil had only been in use for 500 miles. Blackstone reported there was no fuel contamination and, while there was sodium in the oil it could be an oil additive and in any event wouldn't be enough to increase the oil level.

The oil level is still a mystery, but maybe it was a reading error on my part.

In any event, the UOA was not remarkable, though it may actually be a VOA on the oil in question (SN Castrol Edge with Syntec 5w-20). Key readings were:

Sodium. 46
Molybdenum. 80
Boron. 57
Calcium. 795
Magnesium. 1337
Phosphorus. 717
Zinc. 816

Flashpoint. 385

Not sure what to make of this as I don't recall seeing this much magnesium in other oils and the 385 flashpoint seems low for a barely-used synthetic without fuel contamination. When I bought this fill, 5 quarts at WalMart was $21. Now that the price is $26+ I think I'll revert to my familiar Mobil 1, which is now a cheaper alternative.

 

[ottotheclown]

BP uses sodium as do others, the magnesium is showing up in oils like Mobil 1 in large ammounts, looks like you have a almost voa on this oil. IMHO all oils need another look at with SN ratings. Times they are a changing!!!

 

[REDDOG]

What was the fill prior to this oil?

Thanks,

REDDOG

 

[Danh]

Prior to this fill it was conventional Castrol GTX (SM) 5w-20. The car is stored during winter months (there are many of them): this was the fill for that period. The GTX was barely used as the 6 month oil change requirement for the car's warranty isn't much longer than the storage period.

 

[ottotheclown]

Possible source of the sodium was GTX has quite alot. Must be the SM version under the circumstances. Either way my feeling would be like yours little too

scarce re add pack and a few other issues.
Originally Posted By: Danh
Prior to this fill it was conventional Castrol GTX (SM) 5w-20. The car is stored during winter months (there are many of them): this was the fill for that period. The GTX was barely used as the 6 month oil change requirement for the car's warranty isn't much longer than the storage period.

 

[REDDOG]

Thanks. I agree the sodium is from the previous fill of GTX then, as I don't believe the Edge with Syntec contains any sodium.

 

[Danh]

Are we sure that the new Edge with Syntec doesn't contain sodium? Near as I can tell, the old GTX had 150ppm of sodium, so if my sample has 40-50 of sodium attributable to residual GTX, I would have had to have left about 1 1/2 quarts of the old stuff in the engine at change. I know one can't get out everything, but could there be that much left behind with a 5 quart capacity?

 

[ottotheclown]

Here we goIQA listed a SM 5-30 GTX 350 or so sodium. That is correct? Yes, well maybe we have a winner!!!

Originally Posted By: Danh
Are we sure that the new Edge with Syntec doesn't contain sodium? Near as I can tell, the old GTX had 150ppm of sodium, so if my sample has 40-50 of sodium attributable to residual GTX, I would have had to have left about 1 1/2 quarts of the old stuff in the engine at change. I know one can't get out everything, but could there be that much left behind with a 5 quart capacity?