Castrol SYNTEC 5/10W-30

[nelsonlwn]

I have ready many bashers of Castrol SYNTEC full synthetic and many worshipers of GC 0w-30. I am considering going to synthetic and using the OCM on my 2004 Suburban (5.3L) for the full interval. I have discovered that 5/10W - 30 SYNTEC is the ONLY synthetic that meets the GM 6091 spec AND the ACAE A1/A5 spec. From my perusings on here, I have concluded the only meaningful difference between the A5 and A3 spec is the HTHS viscosity, with the A5 being a little lower, but still maintaining the required viscosity over the life of the oil. GC 0w-30 does not meet the GM spec.

SO, someone tell me again why this hydrocracked Synthetic is not the better oil to use in my GM 5.3 for the OLM interval?

Thanks

 

[SSDude]

There is absolutely nothing wrong with using Castrol 5w/10w-30. They are good oils. Check out the UOAs. However, GC using a higher quality basestock and my be more cost effective since you can use it for longer drain intervals. It has also shown lower wear.

 

[Triple_Se7en]

Why would GM test GC when up until a couple months ago, no retailers (at least in Michigan) even stocked it????

Now that the GC has landed on this continent, I would think GM would test it & soon. Don't see why that German oil having lower wear numbers wouldn't pass the test with flying colors either.

 

[Blue99]

quote:

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I have discovered that 5/10W - 30 SYNTEC is the ONLY synthetic that meets the GM 6091 spec AND the ACAE A1/A5 spec.

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Are you referring to the GM 6094M cold temp spec that showed up in the 2004 model year owner's manuals?

If so, any GF-4 dino or synthetic 5w30 will meet this spec.

 

[nelsonlwn]

Yes..I mistyped..It is the GM 6094M spec. I agree with your comment. Some Dino oils meet it such as Havoline and QA. Mobil 1 does not advertise they meet it nor does the Havoline Synthetic. But it is hard to believe a synthetic would not meet a low temp spec that a dino does.

Seems to be the concensus that GC0w-30 does well in the GM 5.3 engines. I have not been able to find UOA results on the SYNTEC 5/10W though.

Thanks for the feedback

 

[Blue99]

Nelson, Here is A Lube Reports Article that gives the specifics of the cold temp pumping viscosities of the GM 6094M spec.

As an example, a 5W must be less than 40,000 cP at -35C. For GF-4, Citgo 5w30 is 21,300 cP and Pennz 5w30 is less than 30,000. So even the majority of dino's will probably meet this spec.

My 99 5.3L Silverado runs quiet with 12 cSt dino oils. It does knock with PAO's and even the heavier viscosity/HTHS of M1 5W-40 T&SUV generated some cold start knock!

 

[NewGuy]

I am currently running Castrol Syntec 5W30 in my 5.3L Tahoe. I currently have 2500 miles on this OCI and I plan to run it for 5-6K and get a UOA. I got pretty good results with regular GTX, so I have high hopes for the Syntec.

I did notice several differences with the Group III Syntec vs. regular dino and other synthetic blends that I have used.

- Much lighter in color vs dino or Mobil 1.
- Doesn't darken in my engine as quick vs. GTX

I like how my 5.3L runs with the Syntec. I believe that it is a good oil and probably has something other than just Group III in it (based upon the color and odor). I will have some results to share within a few weeks.

 

[Buzzsaw]

I don't have much to add to this topic other than I saw 10w30 Syntec at my local Bi-Lo grocery store for $7.13 a quart

 

[haley10]

Syntec Blend also meets 6094M. I was a fan of Syntec 10W-30 myself. I'm running GC now.

, but in the 3800 V-6.

I think you will probably just have to try and get your impression of each in your engine.

I don't know as I trust the OLM completely with any oil mentioned unless confirmed by uoa @ 6K. I would also do that.

 

[sgtgeek]

quote:

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Originally posted by Triple_Se7en:
Why would GM test GC when up until a couple months ago, no retailers (at least in Michigan) even stocked it????

Now that the GC has landed on this continent, I would think GM would test it & soon. Don't see why that German oil having lower wear numbers wouldn't pass the test with flying colors either.

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He is saying the Castrol Syntec 5-30/10-30 which is not the GC 0-30. Different things man....

 

[nelsonlwn]

quote:

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Originally posted by NewGuy:
I am currently running Castrol Syntec 5W30 in my 5.3L Tahoe. I currently have 2500 miles on this OCI and I plan to run it for 5-6K and get a UOA. I got pretty good results with regular GTX, so I have high hopes for the Syntec.

I did notice several differences with the Group III Syntec vs. regular dino and other synthetic blends that I have used.

- Much lighter in color vs dino or Mobil 1.
- Doesn't darken in my engine as quick vs. GTX

I like how my 5.3L runs with the Syntec. I believe that it is a good oil and probably has something other than just Group III in it (based upon the color and odor). I will have some results to share within a few weeks.

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New Guy - any engine noises with the SYNTEC? Mine is quiet with the Havoline 5w30. Want to be sure it stays that way. Had a 2002 5.3 Suburban that clattered like a bad diesel..worse with M1.

Thanks

 

[NewGuy]

Nelsonlwn -

Not a lick of noise with the Syntec 5W30. No piston slap or rattling at all. I am very happy with the way it starts and runs, but the UOA will tell the tale. I think that all Castrol products are better than average and the Syntec seems to work well in my 5.3L. It might not be a Group IV PAO...but if it runs well, has minimal wear and stays clean in the engine...I don't care if it is Group III, III/V or IV. I drive a lot for work and will be chaning this oil in early April. I plan to run M1 10W30 (SM/GF-4) for comparison.

You can buy Syntec for qt on-sale at Advance Auto right now...or for $3.80/quart at Wal-Mart any time.

Havoline is a quality product and I have seen several good UOAs using it in GM engines. I also have 12 quarts of the new Havoline SM 5W30 waiting to go in my Tahoe or my wife's Expedition. However, if the Syntec UOA looks good I might just stick with it.

 

[Whimsey]

quote:

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Originally posted by NewGuy:
You can buy Syntec for qt on-sale at Advance Auto right now...or for $3.80/quart at Wal-Mart any time.

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I was at the Walmart near me in northern NJ tonight and Syntec was more expensive than Mobil 1 SS. In fact it's always been that way

. Heck I can buy Schaeffer's Supreme Blend and have it delivered to my door for less than going to the store for Syntec or Mobil 1

.

Whimsey