Discount oil in Oz.

Autobarn has Nulon X-Protect 15W40 mineral (API SP / CF) at $35 for 5L.

Probably the cheapest API SP oil you will get now days. 15W40 is a decent viscosity grade. It has a naturally low Noack volatility and good shear stability, even as a mineral oil. Fine in an Australian winter. I would use it.
 
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SR5 said:
At SCA in Australia, Castrol Edge 5W30 Euro oils. Sales Ends 20th July 2025.

Castrol Edge 5W30 A3/B4 full synthetic;
ACEA A3/B4, BMW LL-01, MB 229.5, VW 502/505;
KV100 = 12.3 cSt, SA = 1.2%, PP = -39C, FP = 210C;
Half Price, $47.50 for 5L, was $95.

Castrol Edge 5W30 LL full synthetic;
ACEA C3, BMW LL-04, MB 229.51, Porsche C30, VW 504/507;
KV100 = 12.1 cSt, SA = 0.77%, PP = -43C, FP = 194C;
Half Price, $52 for 5L, was $102.

Either of those two should do most people.
Click to expand...
The A3/B4 should have around 1000 ppm ZDDP.
While the LL would have 700 to 800 ppm ZDDP.

Both have 10% or less Noack Volatility.
 
SR5 said:
Autobarn has Nulon X-Protect 15W40 mineral (API SP / CF) at $35 for 5L.

Probably the cheapest API SP oil you will get now days. 15W40 is a decent viscosity grade. It has a naturally low Noack volatility and good shear stability, even as a mineral oil. Fine in an Australian winter. I would use it.
Click to expand...
Your thoughts on 15W40 parallel my own. Were not in Greenland and 5, 10, 15, 20 or 25W is irrelevant to us as we are above the minimum operating ranges for all of them. Even 25W.
from here at random:
https://enginelearner.com/understanding-oil-viscosity-ratings/
Screenshot_20250706_103652_DuckDuckGo.webp


I'm not saying I'm going to stop using 0W and 5W oils any time soon. Just I will also use 15W and 20W without worry.
 
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LordNilesStandish said:
Your thoughts on 15W40 parallel my own. Were not in Greenland and 5, 10, 15, 20 or 25W is irrelevant to us as we are above the minimum operating ranges for all of them. Even 25W.

I'm not saying I'm going to stop using 0W and 5W oils any time soon. Just I will also use 15W and 20W without worry.
Click to expand...
I've run 20W50 all year round, for year after year in Australia. We just don't have the cold starting issues that other countries have. I don't use 20W50 anymore, but I do like a good drop of 15W40. You should only get as much cold starting ability as your climate requires, anything more and you are sacrificing Noack Volatility and Shear Stability for a starting ability that you don't need. It's a poor bargain.

Look at the Mag-1 web page, they have excellent spec sheets.
https://mag1.com/products/

Mag-1 HDEO (diesel engine) 15W40 (CK-4) convention has a Noack = 10%,
Mag-1 PCMO (petrol engine) 10W40 (API SP) conventional has a Noack = 9.9%,
Mag-1 PCMO 5W30 full synthetic (Dexos1-Gen3) has a Noack = 12%,
Mag-1 PCMO 0W20full synthetic (Dexos1-Gen3) has a Noack = 13%.

Given the price difference between conventional and synthetic in Australia, I see the logic in running a thick conventional over a thin synthetic, and change it every 10,000km (6,200 miles).

Australia and Europe are lucky, they still get cheap but good quality 15W40 PCMOs, that can run in most average cars. In North America, 15W40 seems to mostly be a HDEO grade.

More 15W40 talk here, with oil formulator Joe
M104

Thread 'Shell HX5 15w40 formulation'

I already talked about this oil in other threads but i really ask myself how can pour point be so low (-45c) and flash point be so high (245c) for such a cheap oil? These are similar to the SHU 5w40 and even better than most euro grp III 5w40 available. Also it is SN rated and the newer batches are SN+. I suspect it is not made from grp I at all but more likely grp II or even a mix of grp II and III or GTL with low VII. Do you have any other infos about the oil such as NOACK and HTHS? I suspect this oil to be better than what it claims on the jugs for obvious reasons and a great bang for...

Having said all that, I mostly just buy on price. I use most oil types without concern.
 
SR5 said:
I've run 20W50 all year round, for year after year in Australia. We just don't have the cold starting issues that other countries have. I don't use 20W50 anymore, but I do like a good drop of 15W40. You should only get as much cold starting ability as your climate requires, anything more and you are sacrificing Noack Volatility and Shear Stability for a starting ability that you don't need. It's a poor bargain.

Look at the Mag-1 web page, they have excellent spec sheets.
https://mag1.com/products/

Mag-1 HDEO (diesel engine) 15W40 (CK-4) convention has a Noack = 10%,
Mag-1 PCMO (petrol engine) 10W40 (API SP) conventional has a Noack = 9.9%,
Mag-1 PCMO 5W30 full synthetic (Dexos1-Gen3) has a Noack = 12%,
Mag-1 PCMO 0W20full synthetic (Dexos1-Gen3) has a Noack = 13%.

Given the price difference between conventional and synthetic in Australia, I see the logic in running a thick conventional over a thin synthetic, and change it every 10,000km (6,200 miles).

Australia and Europe are lucky, they still get cheap but good quality 15W40 PCMOs, that can run in most average cars. In North America, 15W40 seems to mostly be a HDEO grade.

More 15W40 talk here, with oil formulator Joe
M104

Thread 'Shell HX5 15w40 formulation'

I already talked about this oil in other threads but i really ask myself how can pour point be so low (-45c) and flash point be so high (245c) for such a cheap oil? These are similar to the SHU 5w40 and even better than most euro grp III 5w40 available. Also it is SN rated and the newer batches are SN+. I suspect it is not made from grp I at all but more likely grp II or even a mix of grp II and III or GTL with low VII. Do you have any other infos about the oil such as NOACK and HTHS? I suspect this oil to be better than what it claims on the jugs for obvious reasons and a great bang for...

Having said all that, I mostly just buy on price. I use most oil types without concern.
Click to expand...
You will find this interesting:
https://www.exxonmobil.com/en/basestocks/products/group-ii-base-stocks

Basically how using group II+ base can make a more effective oil. I think it's partially the availability of much higher viscosity base oils for blending which by merit have lower noak, higher flash point and reduce VII requirements. This is reflected in viscosity stability.
So cheaper is sometimes better when talking about higher viscosity grades.
This applies in comparison to group III.
 
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LordNilesStandish said:
You will find this interesting:
https://www.exxonmobil.com/en/basestocks/products/group-ii-base-stocks

Basically how using group II+ base can make a more effective oil. I think it's partially the availability of much higher viscosity base oils for blending which by merit have lower noak, higher flash point and reduce VII requirements. This is reflected in viscosity stability.
So cheaper is sometimes better when talking about higher viscosity grades.
This applies in comparison to group III.
Click to expand...
Yes, that was very interesting, thanks for posting.

That Mobil web page makes some good points. I really like 10W30 and 15W40 Group-II convention or Group-II / Group-III semi-synthetic oils. They are a well balanced product.

Have you ever tried Castrol Magnatec 10W30 (API SP & ACEA A3/B4) semi-synthetic? It's one of my favourite oils, and probably formulated similar to the presentation you linked to. It would probably cover most applications in Australia at a very reasonable price point. That Nulon 10W40 semi-synthetic (API CK-4 & ACEA E8/E11) you recently purchased would be a similar well formulated product.

There is a lot to be gained if you live in a warm climate where you can give away a bit of cold starting ability; and swap it for low volatility, shear stability and a good price point.
 
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SR5 said:
Yes, that was very interesting, thanks for posting.

That Mobil web page makes some good points. I really like 10W30 and 15W40 Group-II convention or Group-II / Group-III semi-synthetic oils. They are a well balanced product.

Have you ever tried Castrol Magnatec 10W30 (API SP & ACEA A3/B4) semi-synthetic? It's one of my favourite oils, and probably formulated similar to the presentation you linked to. It would probably cover most applications in Australia at a very reasonable price point. That Nulon 10W40 semi-synthetic (API CK-4 & ACEA E8/E11) you recently purchased would be a similar well formulated product.

There is a lot to be gained if you live in a warm climate where you can give away a bit of cold starting ability; and swap it for low volatility, shear stability and a good price point.
Click to expand...
That magnatec sounds interesting. I'll keep my eyes open for it.
When I spoke to the Nulon tech he said the reason for 0W and 5W oils is so they can sell and spec the same oil everywhere in the world but the are only really needed in places like Sweden, Siberia, Saskatchewan etc. Which are really cold places.
A 10W is good down to -25 oC which is plenty cold.
25W is good down to -10. I lived in Canberra for 8 years and the coldest it ever got was -8.
I now live in Gold Coast and the coldest it's ever got is about 10 oC.
10W, 15W, 20W is fine for where 95% of the world's population live.
0W and 5W is really just special use cold climate oil.

Anyway, I agree and my current thoughts are semi synthetic > group 3 full synthetic, for reasons discussed above it allows for a better formulated oil with viscocity achieved through base stock over VII.
I'm going to try and cut group 3 'full synthetic' out of my diet. It's now either semi synthetic or proper IV and V.
 
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LordNilesStandish said:
That magnatec sounds interesting. I'll keep my eyes open for it.
When I spoke to the Nulon tech he said the reason for 0W and 5W oils is so they can sell and spec the same oil everywhere in the world but the are only really needed in places like Sweden, Siberia, Saskatchewan etc. Which are really cold places.
A 10W is good down to -25 oC which is plenty cold.
25W is good down to -10. I lived in Canberra for 8 years and the coldest it ever got was -8.
I now live in Gold Coast and the coldest it's ever got is about 10 oC.
10W, 15W, 20W is fine for where 95% of the world's population live.
0W and 5W is really just special use cold climate oil.

Anyway, I agree and my current thoughts are semi synthetic > group 3 full synthetic, for reasons discussed above it allows for a better formulated oil with viscocity achieved through base stock over VII.
I'm going to try and cut group 3 'full synthetic' out of my diet. It's now either semi synthetic or proper IV and V.
Click to expand...
I agree with the Nulon tech, all these 0Wx and 5Wy oils are world spec oils that should work for everyone from Sydney to Siberia. Most people aren't into oil, and they are trying to keep it simple for new car owners. I get it. The bit I don't like is that because 10W30 can't be a Dexos1 (or whatever OEM spec) oil due to viscosity grade requirements on Dexos, it's therefore an inferior oil to some people. That's the bit I dislike.

I try to see the engineering behind the oil, and judge it for what it is. Some Group-III synthetics are well formulated, those two Castrol Edge 5W30's (A3/B4 and LL) above, are well formulated oils that I would happily use any day. It's just that I also appreciate Castrol GTX 15W40 UltraClean (semi-synthetic) as another high quality product.

I once used the older Castrol Magnatec 10W30 (SN, A3/B4) semi-synthetic and the newer Castrol Magnatec 5W30 (SN, A3/B4) full synthetic in the same car. Driving around, I found the semisynthetic 10W30 much smoother. I've never bought the 5W30 synthetic Magnatec since. But I still use the GTX 15W40, Magnatec 10W30, and Edge 5W30.

Valvoline DuraBlend 10W40 semi-synthetic is another of my favourites.
 
SR5 said:
I agree with the Nulon tech, all these 0Wx and 5Wy oils are world spec oils that should work for everyone from Sydney to Siberia. Most people aren't into oil, and they are trying to keep it simple for new car owners. I get it. The bit I don't like is that because 10W30 can't be a Dexos1 (or whatever OEM spec) oil due to viscosity grade requirements on Dexos, it's therefore an inferior oil to some people. That's the bit I dislike.

I try to see the engineering behind the oil, and judge it for what it is. Some Group-III synthetics are well formulated, those two Castrol Edge 5W30's (A3/B4 and LL) above, are well formulated oils that I would happily use any day. It's just that I also appreciate Castrol GTX 15W40 UltraClean (semi-synthetic) as another high quality product.

I once used the older Castrol Magnatec 10W30 (SN, A3/B4) semi-synthetic and the newer Castrol Magnatec 5W30 (SN, A3/B4) full synthetic in the same car. Driving around, I found the semisynthetic 10W30 much smoother. I've never bought the 5W30 synthetic Magnatec since. But I still use the GTX 15W40, Magnatec 10W30, and Edge 5W30.

Valvoline DuraBlend 10W40 semi-synthetic is another of my favourites.
Click to expand...
Oh yeah the increased smoothness is noticeable with 10W oils.
It's like a 5W50 or 10W50 cannot be Porsche A40, even though it's a track oil spec.
A lot of OE specs have narrow viscosity ranges as well. Though I strongly suspect the oils with viscocity outside the specs get the same additives.
I'm starting to look for API SP and A3B4, I think if these two are present the oil is pretty stout.
Bunnings carry a 15W40 Valvoline Durablend $45, which I've been eyeing off:
https://www.bunnings.com.au/valvoline-5l-15w-40-1344-05-engine-oil_p0102733

I've been running the Edge 5W30 in my elderly parents Mazda and it is nice and smooth.
 
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At Repco, 9-22 July.

Penrite Enviro+ GF-S 5W30 full synthetic;
API SP, ILSAC GF-6A;
KV100 = 10.9 cSt, HTHS = 3.2 cP, Zinc = 820 ppm, TBN = 8.0, SA = 0.9%;
Half Price $37 for 5L (was $76). That's $7.40 per Litre.

Penrite Vantage 10W40 semi-synthetic;
API SP, ACEA A3/B4, JASO MA2;
KV100 = 14.1 cSt, Zinc = 1060 ppm, TBN = 11.3, SA = 1.23%;
40% Off for members (free to join) $42 for 6L (was $70). That's $7 per Litre.
 
At SCA, 23 July to 10 August.

Penrite HPR 5 (5W40) Full Synthetic;
API SP, ACEA A3/B4, MB 229.5;
Half Price $43 for 5L.

Castrol Magnatec 10W40 Semi-Synthetic;
API SP, ACEA A3/B4;
Half Price $32.50 for 5L.

Nulon APEX+ Long Life 5W30 Full Synthetic;
API SP, ILSAC GF-6A;
Half Price $47.50 for 6L (six).

Mobil Super 10W30 Mineral;
API SP, ILSAC GF-6A;
Half Price $28.50 for 5L.

Valvoline SynPower FE 5W30 Full Synthetic;
API SL (high ZDDP oil, above SN & SP limits), ACEA A5/B5; Ford 913D;
Half Price $45 for 6L (six).

Also 20% to 25% off K&N filters.

Lots of older cars on the road that would run just fine on the Mobil Super 10W30.
 
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