Oils for DC2R.

**aaronrein** · 05-07-2011 03:15 PM

Originally Posted by krogoth

10w-40 extra 10 full synthetic everyday penrite, great oil, aussie made

thats the other id suggest (y)

**gumus89** · 05-07-2011 11:14 PM

Originally Posted by aaronng

A bit late, but I hope that the threadstarter stuck with the oil that he was using. If he was happy with it and had no oil consumption, then he should stick to it (Edge 5w-30). For street use, there is not much difference going from Group III to Group IV or going from 5w-30 to 0w-40.

Quoted for truth.
The only difference would be not noticeably less wear at start up with the group 4. Ive read something about group 4's being thinner for the same viscosity rating under that standard. If that was true then there wouldnt a loss of power from the 0w-40 at operating temp.

**Bludger** · 06-07-2011 12:14 AM

I've been using Castrol 0w-40 for the last 5 years.

Thinking of going Shell or Mobil 5w-30.

**aaronng** · 06-07-2011 12:27 PM

Originally Posted by gumus89

Quoted for truth.
The only difference would be not noticeably less wear at start up with the group 4. Ive read something about group 4's being thinner for the same viscosity rating under that standard. If that was true then there wouldnt a loss of power from the 0w-40 at operating temp.

If the viscosity rating is the same, then both oils will have the same thickness. If you have a group 4 that is thinner, then the viscosity rating would be lower.

The difference between a 5w-30 and 0w-40 is small enough that you wouldn't be able to measure the power loss on a dyno as the dyno is not sensitive and accurate enough.

Viscosity is only a measurement of the resistance to flow. It does not measure how slippery the oil is. For example, water has a very very low viscosity compared to oil, but is not really "slippery". Oil on the other hand is much higher viscosity and you can see with your own eyes that it is thicker than water. But when put to use as a lubricant, it is more slippery than water, hence giving it better protection properties.

One unknown difference between a Group III and Group IV is that a Group III will tend to cling to metal surfaces for longer, whereas Group IV tends to be less attracted to metal. Not an issue if you drive daily though, only worth taking it into account if you only drive once a week.

**gumus89** · 06-07-2011 04:45 PM

Originally Posted by aaronng

If the viscosity rating is the same, then both oils will have the same thickness. If you have a group 4 that is thinner, then the viscosity rating would be lower.

The difference between a 5w-30 and 0w-40 is small enough that you wouldn't be able to measure the power loss on a dyno as the dyno is not sensitive and accurate enough.

Viscosity is only a measurement of the resistance to flow. It does not measure how slippery the oil is. For example, water has a very very low viscosity compared to oil, but is not really "slippery". Oil on the other hand is much higher viscosity and you can see with your own eyes that it is thicker than water. But when put to use as a lubricant, it is more slippery than water, hence giving it better protection properties.

One unknown difference between a Group III and Group IV is that a Group III will tend to cling to metal surfaces for longer, whereas Group IV tends to be less attracted to metal. Not an issue if you drive daily though, only worth taking it into account if you only drive once a week.

Cool.
Just to clarify what I have read. It seems the standard of viscosity rating are measured at 40 deg C, 105 deg C and 150 deg C. But at room temperature, the synthetic oils will be thinner than their mineral counterparts. This is out of the Bob is the oil guy website.

"A main advantage that the synthetic has over the mineral based oil is the ability to lubricate at startup. Both types of oil have the same specifications at 104°F, 212°F and 302°F. It is the startup viscosity characteristics that separate these oils. Synthetic oils do not thicken as much on cooling. They have better fluidity as the temperature drops.

A synthetic oil that is labeled as 10W-30 is less honey like as a mineral based 10W-30 motor oil at startup. They both have a thickness of 10 at normal operating temperatures. At 75°F the synthetic is not as thick. At 32°F the difference between the two is even greater. At 0°F the mineral oil is useless yet the synthetic works fairly well. Just keep the RPM to a minimum."

He also mentions that the ability for an oil to protect is not due to the oil sticking to the parts, but moreso the flow of oil between the parts.
"Some people have said they use thicker oils because they only use their cars every 2, 3 or 4 weeks. They are afraid that thin oils will fall off the engine parts and result in a lack of lubrication at startup... Anyway, oil on the surface of parts does not lubricate. It is the FLOW of oil between parts that lubricates. Thick, old, waxy oil can only be bad."

I cant afford group 4 oils anyway so it doesnt really bother me :P