Is semi-synthetic 10W-40 still a thing?

Messages
508
Location
Brittany, France
Hi guys, I've been browsing this forum for a while and noticed that 10W-40 wasn't a very popular oil here. I also see some negative talk about it from time to time (some say semi-synthetic cause worse leaks than synthetic etc). It looks like it's still one of the most popular viscosities in europe and a best seller for sure.
While a 5L jug synthetic 5W-40 is around 30€, 10W-40 is only around 20€ or 13/15€ when on sale for brands like Total, Elf or Shell. It is really cheap to get and carries ratings that get better with years and almost similar to the synthetics now (API SN, ACEA A3/B4, MB 229.3...). At this point i almost dont see any reason to use synthetics if the interval is kept relatively short with a mild climate for NA engines.
Why is 10W-40 so popular here ? (besides 5W-40 and 5W-30 mid saps). Is it popular in other parts of the world as well ? Did you guys noticed drawbacks vs synthetics for the aforementioned use ?
 
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4,632
Location
Decatur AL USA
Until recently European Manufacturers tended to specify 3.5+ HTHS and the US Manufacturers 2.9 HTHS minimum. Basically our 5W-30 and 10W-30 are the lower HTHS equivalent of your 10W-40 and 15W-40 Oils.

10W-40 got a bad name in the USA in the early days when it was produced with Group I Base Stock and shear prone VII and tended to have sludge formation issues. Many USA Owner's Manuals specifically forbid the use of 10W-40 for this reason.

Although today's products are much better it has never recovered from it's past in the US.
 
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24,264
Location
Dallas,Tx USA
My 300ZX has this decal under the hood:
300zx oil sticker.jpg
 
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15,059
Location
Canada
There may not be a lot of 10W-40 here; but there is a lot of semi/syn 15W-40 here, which might as well be the same thing, as a lot of it carries dual ratings.
 
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761
Location
South Carolina
I have no problem using 10w40 weights in semi/syn. Never caused a leak. My old fords run good on them. Older american v8s tend to favor thick oil in my humble opinion. Runs quieter at least.
 
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2,337
Location
South Carolina
The U.S and Asian countries are going in the other direction with thinner oil. The EU will eventually follow. 10w-40 never regained popularity after the late 70's sludge problem. It was also about the same time (oil shortages) that U.S. manufacturers were going to thinner oil (5w-30) to improve fuel economy.
 

SR5

Messages
5,902
Location
Down Under
Yes 10W40 semi-synthetic is still very popular in Australia. It‘s often on sale at a very good price here, say $25 (AUD) for 5L, which is about half price. It’s always rated API SN/CF, ACEA A3/B4 and sometimes an older OEM like MB 229.3

Everybody does one: Castrol Magnatec, Shell Helix HX7, Valvoline DuraBlend, Penrite Vantage, etc

I’m running the DuraBlend myself right now, and have 5L of HX7 lined up soon, both 10W40 semi-synthetic.

BTW when I spoke to Valvoline over the phone, they indicated their DuraBlend was about 30 % synthetic and Penrite told me all their semi-synthetics were a minimum of 20% synthetic and sometimes more depending on application.
 
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35
Location
SP, Brazil
I was very used to run Valvoline Durablend 10w40 in my Fiat Marea, very good oil but since valvoline left Brazil I'm using Elf 10w40 even better oil. There are other brands making 10w40 as well such as Shell, Petronas, Petrobras, etc.
 

M119

Thread starter
Messages
508
Location
Brittany, France
Thanks guys. How do you feel about 10W-40 vs 5W-40 ? I was an advocate of synthetic 5W-40 for years and didn't care for 10W-40 as it had ratings likes API SL, ACEA A3/B3 or MB 229.1 while the 5W offerings had ratings likes SN, A3/B4 and MB 229.3/5.
I am still considering going back to 5W after the summer but results seem to be good with 10W in my cars. Oil consumption is identical between both and since i can't resolve myself to extend my intervals longer than 7/8k kms it is better for the wallet.
This brings me to another question. I had a few cars that had 10k kms intervals with only synthetic 229.5 and of course the engine looked brand new from the inside (including my daily driver). How is it possible that my E250 diesel that used to be our familly car for 13 years and now has half a million kms on the clock has zero sludge build up and close to zero oil burning ? pulled the valve cover and nothing, engine is like new but it only had 10/13K kms (sometimes more when my dad forgot about it) using only conventional 15W-40 or 10W-40.
 
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SR5

Messages
5,902
Location
Down Under
Good 15W40 mineral API SN/CF & ACEA A3/B3, $
Better 10W40 semi-synthetic SN/CF & A3/B4, maybe MB 229.3, $$
Best 0/5W40 full synthetic SN/CF & A3/B4 plus various OEMs like MB 229.5, BMW LL-01, Porsche A40, $$$

What do I think about 5W40 synthetic? It’s great !
But I also know my Opel Astra can go it’s whole life on 10k KM (6k miles) oil changes of mineral 15W40 and the body will fall apart before the engine dies of any oil related issues.
 
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SR5

Messages
5,902
Location
Down Under
BTW I always buy 5L jugs, because they are the most cost effective for me. However my car only uses about 4L per oil change, so that leaves me a bit leftover to make a Frankenbrew. Which I just did the other day:

Penrite Vantage 10W40 semi-synthetic A3/B4 (with 1220 ppm Zinc)
Valvoline DuraBlend 10W40 semi-synthetic A3/B4
Valvoline SynPower 0W40 full synthetic A3/B4
Castrol Magnatec 10W30 semi-synthetic A3/B4
Castrol Edge 10W30 full synthetic A5/B5

That should keep the Astra going, just need to wait for the rain to stop, so I can change it out.
 
Messages
24,264
Location
Dallas,Tx USA
If I had to choose between a 0W/5W/10W40 full synth,I would take the 10W40 for the thicker base oil and less viscosity improvers. Not sure if that has any tribological pertinence these days but it makes sense to me layman-wise.
 
Here in Spain, Repsol has a Full Synthetic 10W-40, which is interesting.
No idea what base stock but most likely G3 given the low cost.
It's API SN, A3/B4, , MB 229.3, VW 502/505 and Renault 0700/0710
Can be had online for 21.99€ / 5L
 
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SR5

Messages
5,902
Location
Down Under
Is there any benefit of using a semi-syn 10W-40 vs syn 5W except for the wallet or is the 5W better on all fronts ?
I would say that a full synthetic, even a Group III synthetic, 5W40 would always be a better oil than semi-synthetic 10W40. The specs would support this, as the 5W40 synthetic often carries more OEM specs than the 10W40 synblend.

The real question is, does your car, or oil change interval (OCI), require the better oil?

In Australia, speaking to Penrite over the phone, their semi-synthetics are Group II & III. But in Europe, given their supply lines, I’ve read that their semi-synthetics are often Group I & III, with more Group III to make up for the Group I.

That’s the problem with semI-synthetics, you never know exactly what you are getting and in what proportion. Sure the same is true for full synthetics, which could be a combination Group III & IV & V, but you know the minimum is 100% Group III.
 

M119

Thread starter
Messages
508
Location
Brittany, France
Considering i can't help myself but change the oil every 7/8 k kms instead of the 15k oil change in the manual i think i'm ok. Manual calls for MB 229.1 and pretty much every viscosity is on the chart, from 5W-30 to 20W-50. I've heard that these engines where engineered with 15W-40 in mind back then, FWIW.
 
I've gone from Shell Rimula R4X 15W-40 HDEO to Valvoline Maxlife 10W-40 on my 1988 Escort XR3i.

Ford recommends 10W-40, but allows anything up to 20W-50 in warm climates, like where i live.

My main concern is ZDDP because the Ford CVH engine is a flat tappet design, and on top of that is well known to have poor top end lubrication, and they tend to sludge up if neglected.

Mine was neglected by the previous owner but after 2 1/2 years of intensive care it seems to have survived unscathed.

I have thought about going to a 5W-40 next, i have considered Total 9000 5W-40 which is easy to find and inexpensive, and various UOAs and VOAs show it has a strong add pack with plenty of ZDDP.

Now another thing i have read is that not only ZDDP matters in flat tappet protection, but also base oil viscosity, apparently heavier base oils are better for flat tappets, not sure if this is true, false or both.
 
Messages
3,854
Location
Slovenia EU
Is there any benefit of using a semi-syn 10W-40 vs syn 5W except for the wallet or is the 5W better on all fronts ?
I would say depending where you live... (5w vs 10w...) and how long is your OCI

I am a great fan of Shell oils....and if I compare their semisyn HX7 (XHVI) line with their Ultra range (GTL).... There is no big difference in performances.....I mean if you live in EU where we dont have weather extremes (10w40 grade can be used year around-except for lets, say Scandinavia)....and if your OCIs are reasonable long....

Rimula in my LC is a different story (its GTL HDEO)
 
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Messages
3,854
Location
Slovenia EU
I have thought about going to a 5W-40 next, i have considered Total 9000 5W-40 which is easy to find and inexpensive, and various UOAs and VOAs show it has a strong add pack with plenty of ZDDP.

Now another thing i have read is that not only ZDDP matters in flat tappet protection, but also base oil viscosity, apparently heavier base oils are better for flat tappets, not sure if this is true, false or both.
Oil-club.ru Elf nf 5w40 VOA

VS

Total quartz energy 5w40 VOA
 
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