Castrol GTX Synblend 5w20 6k miles Hyundai Sonata

[anl0109]

Here is my third report for 2009 Hyundai Sonata (2.4L and A/T). Used NAPA kit but same lab as last time (Wix kit) -- ALS in Atlanta.

Out: Castrol GTX Synthetic blend 5w-20 & OEM filter
In: Castrol GTX Synthetic blend 5w-20 and 5w-30 mix & OEM filter

I think this is the longest OCI in terms of time (over seven months) of any car I've ever owned. The lab said everything looks fine. I see that iron is trending up and aluminum is unchanged but will hopefully come down as I poured about 2.5 quarts of 5w-30 oil when I changed it (the rest was 5w-20). Really happy that water/coolant/potassium/lead are looking good.

Questions:
- is GTX part synthetic oil known to contain 100+ ppm sodium and essentially no moly?
- are these silicon readings ok?
- should I extend to 8-9 months and 7k-8k miles?

Code:


Mls on unit 69,500 74,700 80,600

Mls on oil 6,000 5,200 5,900

Sample date 1/1/15 7/2/15 2/12/16



Aluminum 2 5 5

Chromium 0 2 1

Iron 8 9 12

Copper 0 0 2

Lead 0 0 0

Tin 0 0 0

Nickel 0 1 0

Silver 0 0 0

Molybdenum 62 21 6

Titanium 0 0 0

Calcium 1173 1579 1908

Magnesium 618 216 45

Phosphorus 897 788 641

Zinc 993 910 732

Barium 0 0 0

Boron 72 18 25

Sodium 93 269 108

Silicon 9 11 11

Potassium 2 5 0



PROPERTIES

cSt Viscosity 8.72 8.30 7.90

Coolant 0% 0% 0%

Water (%) 0% 0% 0%

TBN N/A 3.7 3.2

 

[69GTX]

I don't know about the synblend, but the regular GTX and their full synthetic don't have sodium. It looks like that is stuff leftover from the last oil change. There's no moly in the regular GTX but some in their synthetic. Looks like 2 oil changes ago could have been with Castrol Edge or something similar.

 

[anl0109]

Originally Posted By: 69GTX
I don't know about the synblend, but the regular GTX and their full synthetic don't have sodium. It looks like that is stuff leftover from the last oil change. There's no moly in the regular GTX but some in their synthetic. Looks like 2 oil changes ago could have been with Castrol Edge or something similar.


Thanks for the post. I've seen Castrol GTX UOA's with and without sodium. This particular GTX oil is discontinued but still curious as I have about 10 quarts left.

The three samples were of the following products:
1) Mobil 1 synthetic 5w-20
2) Peak conventional 5w-20
3) Castrol GTX blend 5w-20

 

[wemay]

Looks great!
Sodium is from PEAK.

 

[WobblyElvis]

I would extend the oil change interval to 7-8k as you suggest. I've gone much farther with no problems.

 

[anl0109]

Thanks, guys. Interesting that such good amount of sodium could be left over.

I'm a bit nervous but don't see why I can't go 7k if not more on this oil. This consistent 3+ TBN number is pretty encouraging.

Last thing...doesn't it look like previous run is just as good even though it was PEAK conventional which is not marketed as a premium product? (And premium or premium-ish is what I think Castrol synblends are.)

 

[aquariuscsm]

Deleted post. I re-read the thread and answered my own question.

 

[anl0109]

Originally Posted By: aquariuscsm
Deleted post. I re-read the thread and answered my own question.


No prob. The first sample was M1 oil, OEM filter. That was including a long road trip (lots of hwy miles) and only 4-5 months of total service. Also, worst temps are in Jan-Feb around here so that run excluded it also.