5W30 V 10W30 engine oil

[Immortality]

For Aussie conditions a 10W-30 would be fine. When looking at oil viscosity numbers the first number 10W refers to the cold oil viscosity rating and the 2nd number (30) the viscosity when up to operating temp.

This is the factory guide for a ecotec equipped model but the important part to see is that the 10W-30 is rated from -20° C so unless you intend to drive the car in a colder climate there isn't really any need to go to a 5W-30 viscosity oil.

 

[KrisDeagle]

So, if I am interpreting that correctly, (though I am using Alloytec not Ecotec obviously) then a 20w/50 should be okay since the temperatures around here are 20-40 anyway?

 

[Ian Johnston]

Fark me, any oil is better than none. I dont know why people wank on about 5W v 10W etc. Unless you are racing, or flogging the guts out of your car every second, it dont matter.
If you have done 250,000ks, it obviously is doing its job. Regular oil changes are more important than oil grade(to a point)

 

[Immortality]

So, if I am interpreting that correctly, (though I am using Alloytec not Ecotec obviously) then a 20w/50 should be okay since the temperatures around here are 20-40 anyway?

In theory, yes. However the alloytec is (or should be) manufactured with much finer tolerances and the engine was designed to work with a 30 weight oil. The cold rating just comes into it depending on the climate you tend to drive it. In Europe or Americas where it gets much colder they probably recommend a 0W-30.

 

[KrisDeagle]

Fark me, any oil is better than none. I dont know why people wank on about 5W v 10W etc. Unless you are racing, or flogging the guts out of your car every second, it dont matter.
If you have done 250,000ks, it obviously is doing its job. Regular oil changes are more important than oil grade(to a point)

Yes but I have only had the car since about 250000kms, the other 250000 could have been correct...who knows?

In theory, yes. However the alloytec is (or should be) manufactured with much finer tolerances and the engine was designed to work with a 30 weight oil. The cold rating just comes into it depending on the climate you tend to drive it. In Europe or Americas where it gets much colder they probably recommend a 0W-30.

Ah, cheers for that. Funny how things work in theory but not necessarily in practice.

 

[Slow Joe]

Hi. I'm brand new to joining anything , and as of yesterday a brand new Commodore owner. It's a 2005 VZ executive sedan with 203,000 KLM's . The thing I googled was to find out if the oil recommended in the handbook 10W/30 SL GF-3. Was a synthetic, semi, or a mineral oil. and would I still use it with this amount of mileage.

 

[figjam]

I don’t intend to be a smart RS by saying use the search function, but that there is a myriad of threads to amaze and confound you about what oil to use, everybody has a different opinion and liking.
Even more so when you start researching what synthetic and semi-synthetic really means.

Some basic info ...... http://www.pqiamerica.com/apiserviceclass.htm

 

[RiCeY]

Always use full synth in alloytec, since Holden went to full synth Dexos oils I haven't seen a single sludged engine.

 

[HSV126]

5W30 FULL SYNTHETIC REGARDLESS OF KM'S. END OF STORY