Thinner motor oil?

[RedDevil]

So Green Oil is more like -5W20 than 0W16...
I can confirm that Green Oil does improve cold start economy.
Winter 2014-15 was on Green Oil and showed less of a FE dip than the very soft 2013-14 winter on 'previous batch' which was supposed and explained to be 0W20 but showed up on the bill as 5W30...
Then last winter on regular 0W20 was good too, while that winter was just 'soft'.

My FE graph october 2012 to now:
(Worst FE in winter 14/15 was a spirited long drive under high wind and rain.
Worst FE's in winter 15/16 were all service and recall related)

Green Oil was definitely better than Unknown Type, and probably better than 0W20.
I'm useless...

[Ecky]

Yeah I dunno about yours, but my Insight sounds like a diesel when starting at reeeeaally cold temperatures.

[RedDevil]

It is a 4-banger, so it runs like a typical 4 banger in the cold - slightly raised, actually not that bad, even at -14°C which is about the coldest I've seen with it. But no torque, it needs to rev to accelerate unlike when it is warm.

If anything, thin oil makes it rev less at idle.
It also heats up slower. It apparently regulates down the fuel injection when the engine encounters less friction.

[Fingie]

the engine will idle slower when it's experiencing less load.

This thread inspires me to try thinner engine oil.

[Vman455]

The low temperature kinematic viscosity isn't necessarily identical. For example, Amsoil's Signature Series oils:

0W-20: 46.6 cSt@40C
0W-30: 58.2 cSt
0W-40: 85.7 cSt

Buuut...viscosity testing for the "W" designation happens at temperatures much lower than 40C, which aren't reported on any data sheets that I've seen.

[Ecky]

EDIT: Moving this discussion to my build thread.

http://ecomodder.com/forum/showthrea...-29288-39.html

[ThermionicScott]

Originally Posted by Vman455

The low temperature kinematic viscosity isn't necessarily identical. For example, Amsoil's Signature Series oils:

0W-20: 46.6 cSt@40C
0W-30: 58.2 cSt
0W-40: 85.7 cSt

Buuut...viscosity testing for the "W" designation happens at temperatures much lower than 40C, which aren't reported on any data sheets that I've seen.

I know this is an old-ish thread and all, but I've been searching and reading a bunch of old threads since joining recently. So, if it helps anyone following this thread or stumbling across it in the future...

The 40°C (104°F) viscosity isn't much of a low-temperature test, and is mostly a throwback to earlier days of oil standards. It does give you a glimpse of how thick the oil is along the way to being warmed up, but...

The 100°C viscosity rating is of more interest for operating temps. (And I have no doubt it was chosen in the beginning because boiling water is a really convenient way to heat up something to a stable 100°C. )

The temperature used for the low-temp "W" rating depends on the rating they're going for, and there are two tests, pumpability (MRV) and cranking viscosity (CCS). So, for example, a 5W is tested at -35°C for pumping, and -30°C for cranking. At least one of these is usually provided on an oil's data sheet.



Hope this helps.

[oil pan 4]

So the 5w-40 I use is just about perfect.

[ThermionicScott]

Originally Posted by oil pan 4

So the 5w-40 I use is just about perfect.

I like it a lot in my old VWs (I have a stash of CI-4 Rotella). Good film strength at operating temps, but flows way better at startup than the straight-30 in the operating manuals.

[ecocruze]

Just curious on the whole thinner oil subject. I k ow this seems to be more focused on the green or next oil, but if a vehicle is driven ecomodder style wouldn't it be assumed we could go with a thinner oil. I have the 1.4l turbo Cruze. I want to switch to 0w20 since my car is typical to only do short trips so cold start efficiency is a must. But I drive so lightly that I feel I could go thin regardless. Could it be detrimental to my turbo even though I rarely enter any boost.50 mpg+ typically on 13 miles commute. Just looking for a little input. Thanks