GF4 5W-30 vs. 10W-30 dino

novadude · Nov 30, 2004

I have always felt that 10W-30 made for a better choice than 5W-30, based on the fact that 5W-30s always seemed to shear out of grade in UOAs (dino oils). With the advent of GF-4, it sounds like better basestocks are being used in 5W-30 oils, but not necessarily in the 10W-30s.

Could it be that the scales have tipped, and now 5W-30 is the dino oil grade of choice? I guess we will have to wait on the UOAs to know for sure.

What are your thoughts?

Flimflam · Nov 30, 2004

quote:

Originally posted by novadude:

What are your thoughts?

Even if the new GF-4 5w-30 was Group 4,5,6.....even Group X, that does not mean it automatically becomes the better oil than say, 10w-30, 20w-50 that use Group 1 or less.

Many oils in here post super wear numbers even though they arev made with primitive Base Stocks. Contrastingly, some oils show terrible wear numbers even they are pure, 100% PAO Base Stock.

"It is not how big your Group # is. It's what you DO with it that counts."

haley10 · Nov 30, 2004

I know that Castrol GTX and Pennzoil already meet GF-4 in 10W-30. This would be a non-issue since they already use quality basestocks. There would be no superior advantage to 5-30 over 10-30 in these two or Chevron/Havoline.

I think conventional wisdom still applies with these brands. Most starburst dinos will thin somewhat by design to get the energy conserving rating.

69 Riv GS · Nov 30, 2004

quote:

originally posted by Flimflam:
"It is not how big your Group # is. It's what you DO with it that counts."

I believe there's much truth in this statement!
It's the quality of the entire formulation that makes the difference, and I feel this includes more than can be seen with a typical VOA; - or knowing which base oil blend is used).

novadude · Nov 30, 2004

Let's assume for one minute that both the 5W-30 and 10W-30 are approved for your engine. Let's also assume that the add packs are identical. Let's go one step further and assume that the 5W-30 is a GRII/GRIII blend, and the 10W-30 is a lesser quality basestock.

Would the 5W-30 hold up better over extended drains?

Whimsey · Nov 30, 2004

In addition to the base stock the additive package used is very important. With more vehicles using 5W-30 now a days I think the oil companies are investing more in making a better 5W-30 than 10W-30. Take Motorcraft for example. They "upgraded" their 5W-30 to a "synthetic blend" recently. But not the 10W-30 as of yet. Plus a lesser base stock oil need more additives to make up for the lesser base stock. That's not always desireable.

Whimsey

Terry · Nov 30, 2004

All things being equal a SM/GF4 5w-30 will be a "better" lubricant compared to a 10w-30 of the same brand that is not.

Volatility, extended drains,and hopefully lubricity "should" be improved.

As far as comparing UOA's here you have got to understand that outside variables have a tremendous effect on the results. Most that are listed here are not interpreted properly or fully disclosed when posted.

A really well maintained engine running a average oil and driven gently will show well.

A hard driven engine with coolant,poor air filtration,deposits, fuel dilution will make the highest quality lubricant look terrible.

csandste · Nov 30, 2004

FWIW I've moved my 5w30 use from three to nine months out of the year. GF-4 may make it a twelve month pick. I seem to get better mileage with 5w30 and reduction in start-up wear is important. The Pennzoil 5w30 seemed to burn off a bit more than the ST 10w30 but at less than a half quart for four thousand miles that's no big thing.

69 Riv GS · Dec 1, 2004

quote:

originally posted by novadude:
Let's assume for one minute that both the 5W-30 and 10W-30 are approved for your engine. Let's also assume that the add packs are identical. Let's go one step further and assume that the 5W-30 is a GRII/GRIII blend, and the 10W-30 is a lesser quality basestock.

If the GF-4 10w-30 was using a "lesser quaility basestock" blend(Grp I content), a stronger/different additive package along with correction fluid/s would have to be used to meet the the oxidation and volatility specs. Formulation costs would be roughly the same using a Grp II+ base oil blend while also keeping production "simpler" by using the same additive package as the 5w-30. Here's a quote from ChevronTexaco regarding this very subject; - in this post.

novadude · Dec 1, 2004

Now that GF4 is here, I am thinking about giving up my 10W-30 preference for 5W-30. Wise choice, or not?

I started to shy away from 5W-30 when I saw it shear to a 20 wt. in my UOAs. 10W-30 does not shear for me, even after 5k miles (my new "normal" interval). I am thinking that the new GF-4 oils may not shear out of grade as quickly. Right or wrong?

Any reason to stick with 10W-30?

novadude · Dec 1, 2004

c'mon... no one wants to rehash the old 5W vs. 10W debate now that we have GF4 oils?

novadude · Dec 1, 2004

quote:

All things being equal a SM/GF4 5w-30 will be a "better" lubricant compared to a 10w-30 of the same brand that is not.

How about GF-4 5W-30 vs. GF-4 10W-30? Any advantage to 5W, now that the formulations are improving?

The Oil Expert · Dec 2, 2004

Noavdude,how about this 5w30 in the winter, 10w30 in the summer.Make sure they are both ILSAC-GF-4.

GF4 5W-30 vs. 10W-30 dino

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