How do I choose between all these viscosity options?

[literatesavant]

The last time I was regularly changing my own oil, I owned 1998 and 2003 Hondas. I then moved from the US to Australia, bought 2012 and 2016 Hondas, and no longer had a garage, so I've had the oil changed by my mechanic. Now I have a garage again and it's time for some oil changes, so I pulled out my owner's manuals and found something surprising: my recollection is that my older Hondas recommended one oil weight for cold conditions, and one for warmer ones. My new ones recommend from 1 to 4 possible weights across three different temperature ranges. For example, this is from my 2012 Honda Jazz (Fit) manual:

-30 to +40C: 0W-30, 0W-40, 5W-30, 5W-40
-20 to +40C: 10W-30, 10W-40
-15 to +40C: 15W-40

The manual itself gives no indication of how I would choose between these, other than the operating temperature conditions. Needless to say, where I live in Australia the lowest winter temperature might be 0C on a couple of days, which suggests that I could choose any of these 7 weights of oil! My mechanic used 5W-30 at the last change. The car has 166k kms on it, I've only owned it for 2 years and have no prior service records. So: what else should I take into consideration here, when choosing an oil weight?

 

[oggb]

I'd probably run a syn 10w40 in almost everything if I lived in Australia. Wouldn't think too hard about it. 0/5/10w30 would be fine too.

Probably wouldn't even notice a difference in how fast it cranked/started using 15w40 vs. 0w30 at 0C unless your battery was weak to begin with.

 

[Brian123]

Do they ever get Snow in Australia?

 

[carviewsonic]

Middle of the range (ish) for all those viscosities is 10W-30, so I would run that. What is the most commonly sold viscosity on store shelves there?

 

[literatesavant]

Do they ever get Snow in Australia?

Only in a couple of mountainous areas - vast, vast majority of people here would never encounter snow or temps much below 0C.

Middle of the range (ish) for all those viscosities is 10W-30, so I would run that. What is the most commonly sold viscosity on store shelves there?

Good question, it depends on the auto parts store and the brand. Penrite is an Australian oil brand that seems to sell a huge variety of both weights and additive mixes for each weight - it is dizzying, when in the US I just bought Mobil 1 15W-30 and never gave it any other thought. But I wanted to put 10W-30 in the Jazz for this change, and the shop I went to didn't have that from Penrite, so I got Castrol.

I've always used full synthetic in my cars.

 

[wpod]

0W, 5W,10W-30 or 40.

 

[ZeeOSix]

If 0 deg C is the coldest expected, then I'd go with 10W-30 or 10W-40.

 

[literatesavant]

So why do they list multiple options per temperature range? Is it just basically saying, "Whatever you can get from this list will be fine?"

 

[SubieRubyRoo]

So why do they list multiple options per temperature range? Is it just basically saying, "Whatever you can get from this list will be fine?"

Yes, but when you’re dealing with high temps, viscosity @ 100C is important. Use any of the Xw40s and never worry about it!

 

[ZeeOSix]

So why do they list multiple options per temperature range? Is it just basically saying, "Whatever you can get from this list will be fine?"

What's the hottest temp you'd ever see? If it's over 40C (104F) I'd go with a xW-40.

 

[literatesavant]

What's the hottest temp you'd ever see? If it's over 40C (104F) I'd go with a xW-40.

There will definitely be a few 40+ degree days every summer, so this makes sense to me. I'll keep that in mind for next time.

 

[mahanddeem]

Your winters seem to be of 10wX kind of oil
Your summers seem to be of w30 or w40 kind of oil.
10w(30)40 seems to be your main choice

 

[SubieRubyRoo]

Your winters seem to be of 10wX kind of oil
Your summers seem to be of w30 or w40 kind of oil.
10w(30)40 seems to be your main choice

If the coldest conditions the OP will see are above 0* (F or C) and he is concerned about high summer temps, 10w40 is the do-it-all oil. Depending on specs required, there may be specific exceptions where a 0w40 is not necessarily needed, but meets higher performance standards.

 

[Lubener]

10w-30 or 10w-40 should cover all temperature extremes in your area.

 

[SR5]

Hi Mate,

Most things would work for you, some good examples of suitable oil often on sale in Australia
- 5W30 full synthetic e.g Nulon Longlife, Penrite Full syn, Shell HX8, Castrol Magnatec, Valvoline SynPower
- 10W40 semi-synthetic (API SN and Euro A3/B4) all the majors have one e.g. Castrol Magnatec, Penrite Vantage, Shell Helix HX7, Valvoline EngineArmour, etc
- 15W40 mineral / semi-syn e.g. Castrol GTX UltraClean, Shell Helix HX5 etc.


If you are prepared to wait a week or two, there is always something on sale between Repco, Supercheap Auto and AutoBarn. Given your car can run almost anything, just buy what is on sale.

Discount oil in Oz.

At Repco in Australia, 14-24 February 2019. Castrol Magnatec 10W40 semi-synthetic, API SN/CF and ACEA A3/B4 is $25 for 5L (save $24) Valvoline XLD Premium 15W40 mineral, API SL/CF is $17 for 5L (save $23)

bobistheoilguy.com

Right now I'm running Shell Helix Ultra 5W40 full syn (A3/B4) in one car, and Nulon 5W30 LongLife full syn (Dexos1-Gen2) in the other. Both picked up on sale. I've also got a load of GTX 15W40 UltraClean semi-synthetic ready to go.

 

[BMWTurboDzl]

The last time I was regularly changing my own oil, I owned 1998 and 2003 Hondas. I then moved from the US to Australia, bought 2012 and 2016 Hondas, and no longer had a garage, so I've had the oil changed by my mechanic. Now I have a garage again and it's time for some oil changes, so I pulled out my owner's manuals and found something surprising: my recollection is that my older Hondas recommended one oil weight for cold conditions, and one for warmer ones. My new ones recommend from 1 to 4 possible weights across three different temperature ranges. For example, this is from my 2012 Honda Jazz (Fit) manual:

-30 to +40C: 0W-30, 0W-40, 5W-30, 5W-40
-20 to +40C: 10W-30, 10W-40
-15 to +40C: 15W-40

The manual itself gives no indication of how I would choose between these, other than the operating temperature conditions. Needless to say, where I live in Australia the lowest winter temperature might be 0C on a couple of days, which suggests that I could choose any of these 7 weights of oil! My mechanic used 5W-30 at the last change. The car has 166k kms on it, I've only owned it for 2 years and have no prior service records. So: what else should I take into consideration here, when choosing an oil weight?

IMO typically 10w/15w-XX oils for passenger cars are cheaper to produce and priced accordingly. That's their only advantage.

 

[ka9mnx]

Euro (A3/B4) 0w-40 or 5w-40.

 

[SR5]

These are on sale right now in Australia, they would all be fine in your 2012 Honda.

At SuperCheap Auto, 16-26 Feb

Nulon Apex+ 5W30 Full Synthetic,
API SP, ILSAC GF-6A,
Half Price, $45 for 6L.

Castrol Edge 5W30 Full Synthetic,
ACEA A3/B4, MB 229.5,
Half Price, $43 for 5L.

Mobile Super 3000 X2 5W40 Full Synthetic,
API SN, ACEA A3/B4, Porsche A40,
Half Price $37.50 for 5L.

At Repco, 8-21 Feb.

Valvoline Engine Armour 10W40 semi-synthetic,
API SP and ACEA A3/B4,
Half Price $30 for 5L.

 

[Eddie]

I would use a 5w30 Castrol Edge if cost no object. Then a 5w30 blend. That viscosity covers the temp range and should be easily avail. Ed

 

[Yah-Tah-Hey]

The last time I was regularly changing my own oil, I owned 1998 and 2003 Hondas. I then moved from the US to Australia, bought 2012 and 2016 Hondas, and no longer had a garage, so I've had the oil changed by my mechanic. Now I have a garage again and it's time for some oil changes, so I pulled out my owner's manuals and found something surprising: my recollection is that my older Hondas recommended one oil weight for cold conditions, and one for warmer ones. My new ones recommend from 1 to 4 possible weights across three different temperature ranges. For example, this is from my 2012 Honda Jazz (Fit) manual:

-30 to +40C: 0W-30, 0W-40, 5W-30, 5W-40
-20 to +40C: 10W-30, 10W-40
-15 to +40C: 15W-40

The manual itself gives no indication of how I would choose between these, other than the operating temperature conditions. Needless to say, where I live in Australia the lowest winter temperature might be 0C on a couple of days, which suggests that I could choose any of these 7 weights of oil! My mechanic used 5W-30 at the last change. The car has 166k kms on it, I've only owned it for 2 years and have no prior service records. So: what else should I take into consideration here, when choosing an oil weight?

5W-30