5W30 Dexos vs. 10W30

[KCJeep]

As long as there is no cold crank issue like approaching zero F, there is no perceptible difference between 10w30 and 5w30 in actual use.

I used 10w30 in everything for decades year round without the slightest issue. When I was a kid 10w30 was the thin oil, we used 10w40 even in South Dakota winters for years.

 

[hatt]

That's my thinking. 95% of my cold starts are going to be above 50F. Most of those above 70F. If you think you should run 5w over 10w then common sense would indicate that 0w would be better than both. If 10w30 is an obsolete syn grade, 5w30 syn is just as obsolete.

 

[Garak]

The 5w30 grade is still specified for current motor vehicles, and some manuals do recommend A1/B1 A5/B5 choices. I don't think any new motor vehicles call for a 10w30 these days, particularly a synthetic. 10w30 is fairly obsolete, synthetic or not, outside of HDEO.

Note that obsolete does not mean useless or harmful or dangerous.

 

[hatt]

The question isn't what oil is specified by manufacturers. They have numerous other aspects to look at like people who aren't going to buy a syn, CAFE, etc. It's the technical quality and performance of the oil. If you believe you need more than a 10w30 has to offer, why stop half way? Why not go straight to 0W-30? Doesn't Mobil1 follow this thinking?

 

[Garak]

Well, it's about the definition of "obsolete." An obsolete computer can still be very serviceable and useful. So can an obsolete motor oil grade. 10w-40 and SAE 30 are definitely obsolete, but still has a lot of valid uses.

Mobil 1 does follow the thinking that 0w30 AFE is a valid choice where 10w30 or 5w30 ILSAC grades are recommended. However, not all their customers necessarily agree, and many just buy what the manual says. And, of course, not everyone will buy synthetic, as you mention. I've used 5w30 conventional in most of my vehicles that allowed or called for 10w30, simply because of the climate here, and I stick with one thing year round wherever possible.

If someone doesn't think a 5w30, particularly synthetic 5w30, is good enough, I'm not sure that 10w30 is really the solution.

 

[HTSS_TR]

Originally Posted By: Garak
Well, it's about the definition of "obsolete." An obsolete computer can still be very serviceable and useful. So can an obsolete motor oil grade. 10w-40 and SAE 30 are definitely obsolete, but still has a lot of valid uses.

Mobil 1 does follow the thinking that 0w30 AFE is a valid choice where 10w30 or 5w30 ILSAC grades are recommended. However, not all their customers necessarily agree, and many just buy what the manual says. And, of course, not everyone will buy synthetic, as you mention. I've used 5w30 conventional in most of my vehicles that allowed or called for 10w30, simply because of the climate here, and I stick with one thing year round wherever possible.

If someone doesn't think a 5w30, particularly synthetic 5w30, is good enough, I'm not sure that 10w30 is really the solution.

Mobil website recommends only 10W30 for Honda S2000 of all model years for operating in warmer climate above 0F, just like Honda's recommendation.

 

[Garak]

Of course there are exceptions. But, they do the 0w30 recommendation as the general rule.

 

[SR5]

My problem with 10W30 synthetic, is that no one is selling it to me. Same with 0W30, I've never seen either on the shelves around me. Unless I've missed them both completely.

Given my hot climate I would happily run a 10W30 synthetic.

However if I was a manufacturer, faced with the choice of producing a 30 wt synthetic oil in Australia. Given the limited market size of my local community, which probably allowed only one 30 Wt oil be produced due to economics. Between the grades of 0W30, 5W30 and 10W30, I think the 5W30 is the logical choice. The best balance of low VII load, with good cold starting ability. Also the most recommend by car manufacturers.

I would happily run a 10W30, but I don't think it would sell in large volumes. I don't feel hard done by, having only a 5W30 synthetic easily available.

To me the big difference is not between 5W30 and 10W30, it's between ILSAC oil and A3/B4 oil. The ACEA A3/B4 is my heavy 30wt oil, and the ILSAC GF-5 is my light 30wt oil. The me HTHS counts more than which cold cranking test it passed. I gave some figures before where a 10W30 and a 5W30 had exactly the same vis at 40C. Granted one was a mineral and one was a synthetic.

Probably what I'm trying to say (badly) is that the traditional xW-y oil viscosity label, is quite a simple metric that only helps to a limited degree.

Take my GM car, they allow 10W30 and 15W40, but not 10W40. What they are really saying is don't use a cheap mineral 10W40 with lots of volatile VIIs that gunk up the engine. I'm sure GM would have no problem if I ran a synthetic M1 0W40 or a mineral HDEO 15W40.

 

[Garak]

Originally Posted By: SR5
My problem with 10W30 synthetic, is that no one is selling it to me. Same with 0W30, I've never seen either on the shelves around me. Unless I've missed them both completely.

As I've mentioned before, up here, 10w30 synthetic ILSAC stuff has all but disappeared from at least one retailer. It's just taking up valuable shelf space. The old school guys that insist on 10w30 usually aren't buying synthetic, anyhow.

And yes, the big difference is HTHS. So few people outside of BITOG don't understand that. Even here it escapes some people. If a 5w30 ILSAC grade is, for some reason, too thin for one's application, then a 10w30 ILSAC grade isn't the solution at all.

 

[Shannow]

Australia missed/skipped the 10W30 synthetics, and alas will never get them.

Agree wholeheartedly that the 5W30 A3/B4 is the pick of the Oz bunch.

 

[SR5]

Yep, here the M1 5w30 is ILSAC GF-5, while the Castrol Edge 5w30 is ACEA A3/B4. Two completely different synthetic 5w30 oils, with different HTHS.

Same with the 10w30 semi-synthetics around me, half are A3/B4 and the other half are GF-5.

To me the decision is GF-5 Vs A3/B4. The oil weight is of secondary consideration. (Feel free to replace A3/B4 with E7 or E9 in Canada)

 

[Ducman]

Originally Posted By: Shannow
Australia missed/skipped the 10W30 synthetics, and alas will never get them.

Agree wholeheartedly that the 5W30 A3/B4 is the pick of the Oz bunch.


We used to get the 10w30 grade here in Mobil 1 up until around 2007(just before dexos) it had the gold cap on the bottle and all. Mobil dropped it and replaced it with 5w30 grade(silver cap on the bottle) after the owners manuals were changed to recommend only the 5w30 grade.
I think Mobil saw the writing on the wall with the way GM was going and made the Mobil 1 in the lighter grade for the bulk of the market going forward.

The gold bottle packaging was reserved for the 0w-40 grade Mobil 1.

 

[Ducman]

Originally Posted By: SR5
Yep, here the M1 5w30 is ILSAC GF-5, while the Castrol Edge 5w30 is ACEA A3/B4. Two completely different synthetic 5w30 oils, with different HTHS.

Same with the 10w30 semi-synthetics around me, half are A3/B4 and the other half are GF-5.

To me the decision is GF-5 Vs A3/B4. The oil weight is of secondary consideration. (Feel free to replace A3/B4 with E7 or E9 in Canada)


I'm personally quite content to run the GF-5 version of the 10-30 grade in my favourite brand for now.

I think if I wanted an oil with more HTHSV, I would simply jump straight to any of the full synthetic 0w-40 offerings and bypass the 5w30 A3/B4 stuff.

The oil weight classification is totally misleading in some cases.
As we know, HTHS is more accurate in determining the suitability of the oil.

 

[HTSS_TR]

More and more 10W30 of all types(syn, dino ...) are on clearance table(s), and this is good for my wallet.

I can use 10W30 in my S2000 and V70, I don't mind take all for $1/qt or less.

 

[Garak]

Originally Posted By: SR5
Yep, here the M1 5w30 is ILSAC GF-5, while the Castrol Edge 5w30 is ACEA A3/B4. Two completely different synthetic 5w30 oils, with different HTHS.

Yes, up here, they're both ILSAC ones, of course. I believe there is a Castrol 5w30 that's A3/B4, but it would be one of those Castrol OE Professional things, that one won't get outside a dealer.

It's interesting to note that Walmart is starting an M1 sale today, and 10w30 is excluded. I wonder if they're going to cut back on 10w30 availability there. Their oil selection can be a bit chaotic at times.

 

[Ducman]

Originally Posted By: Garak
Originally Posted By: SR5
Yep, here the M1 5w30 is ILSAC GF-5, while the Castrol Edge 5w30 is ACEA A3/B4. Two completely different synthetic 5w30 oils, with different HTHS.

Yes, up here, they're both ILSAC ones, of course. I believe there is a Castrol 5w30 that's A3/B4, but it would be one of those Castrol OE Professional things, that one won't get outside a dealer.

It's interesting to note that Walmart is starting an M1 sale today, and 10w30 is excluded. I wonder if they're going to cut back on 10w30 availability there. Their oil selection can be a bit chaotic at times.


Castrol Edge Titanium 5w30 A3/B4 is available just about everywhere here in OZ through the main retailers and at times it's even on sale.

Also no Mobil 1 0w30 grade at all. I would say they deem it to be irrelevant in our climate.

Amsoil used to recommend(for a short period) their SS 0w30 as the preferred grade for the US equivalent of my vehicle.
They have since revised this early position and their primary recommendation is for 5w30 grade SS with a further recommendation for the 10w30 grade at temps above 0 F.

 

[SR5]

Originally Posted By: Ducman

Castrol Edge Titanium 5w30 A3/B4 is available just about everywhere here in OZ through the main retailers and at times it's even on sale.


Yep, Edge 5w30 A3/B4, you can find it anywhere here, and sometimes at quite good sales prices.

BTW Ducman, well done for running a GF-5 10w30, and breaking the Aussie "Thicker is Better" mentality.

For many years (decades) Castrol Edge 10W-60 was my Thick oil, and Edge 0W-40 was my Thin oil.

I have the turning circle of an ocean liner, so now, after many years, I think the Edge 5w30 A3/B4 is also a good oil, but I have never purchased an ILSAC grade oil yet.

I will admit, to have second glanced, some Valvoline SynPower DX1 5w30 (synthetic, SN, GF-5, Dexos 1) when at a very good price. But I have yet to find the courage to purchase it.

 

[Ducman]

This 10w30 grade is the thinnest oil I've ever run in anything my whole life.
Mobil 1 10w30 was HSV's only recommendation at the time, so I went with what I considered to be a slightly better oil than the Mobil 1.
It's all good, and it's also a personal learning curve.
The oil pressure drops very slightly at idle after a very very long drive on the highway.

It's not that I don't dream of thicker oils though.
I have plans to build a really nice new LS2 for the car from the ground up, and it will in all likelihood have Amsoil SS 0w-40 grade (AZF) in the sump from the first oil change at 1000 Kms.

 

[Garak]

Originally Posted By: Ducman
Castrol Edge Titanium 5w30 A3/B4 is available just about everywhere here in OZ through the main retailers and at times it's even on sale.

Here, off the shelf, the only oddball 5w30 grade I ever saw was the ACEA C sequence Mercedes stuff. All our A3/B3 A3/B4 stuff (at least on the shelves and not at the dealer) is 0w-40, 0w-30, and 5w-40, with Mobil and Castrol being virtually the only game in town, at least through normal retail channels. M1 0w-40 and Castrol 0w-40 are easy to find, as is GC 0w-30. Castrol 5w-40 is a little harder to find, but not that bad.

I'm sure they don't want people confusing an ILSAC 5w30 with an A3/B4 one, or an E6, E7, E9 one.

When the Delvac 1 LE 5w30 starts showing up in retail, they'll hide it off in the corner with the rest of the HDEOs.

SR5: There's certainly nothing wrong with an ILSAC 5w30 (or 10w30) where specified, and even sometimes where not. We here know that it's not always interchangeable with the thicker 5w30 (at least in certain applications, in others it can be). But, too many people just can't read manuals or bottles. One can go outside of specification if one understands what one is doing, but so few people even understand what they should be doing in the first place.

Like I've said before, when a parts man told me that 0w-40 was too thin for my Audi but an ILSAC 10w30 was not, well, that tells it all.

 

[Ducman]

It's the whole Xw-XX rating thing that's the problem.
The system certainly served it's purpose back in the day when mineral oils ruled the landscape.

These days with the wide variation in KV within a given rating due to the resource conserving characteristics of some finished oils (Thankyou CAFE).
The old rating system has flaws and is redundant as far as the educated are concerned here on BITOG.
But as you correctly point out the proletariat/general public are still coming to terms with interpreting their owners manual. Of course some manuals are better than others.

That's where the HTHSv has shown to be the most relevant guide of all to the educated here on BITOG.
As we know, a top of the line synthetic 0w-40 grade oil will have a far higher viscosity at 40 C than any Gf-5 10w30 grade.

I suppose that's why the manufacturers such as GM are moving to an in house spec with a name that's easy for the public to recognise as opposed to a set of spec's with numbers.
It effectively guides the everyday consumer in the desired direction when used in conjunction with the OLM's.

I would rather see a simple number like HTHSv being used as a universal rating system along with a cross reference to manufacturer specs and approvals.

For the rest of us here on BITOG, we are eternally doomed to obsess over the minute details of any given finished oil.
Some times I long for the old days when I was mostly ignorant, as ignorance is bliss. When you're ignorant, you don't know how ignorant you are.

But knowing what I know now, I know that I know nothing. I'm just better educated thanks to BITOG and a few key members with much more education than myself.

For me personally the best part of the whole process as things stand today, is taking comfort in knowing what brand of oil I'm going to be putting in the engine at any time whether it be right or wrong for various reasons.