JCOA

The reason I am asking is that the 0W30 is thinner when cold. When I say cold I mean when the engine is warming up. The first 8 miles of my commute is downhill and the oil just does not warm up. It might be 140 degrees, but usually cooler by the time I get down the hill. I have read on BITOG, from a contributing editor, that cold oil is just too thick for engines regardless of viscosity, even a 0 weight. I am planning on using either 0W30 or 0W40 because of this, and also because a 0 weight oil requires a better base stock (a true synthetic), but I am open to ideas. A 0W30 is suppose to be thinner than a 0W40 at cooler temps. I know that Mobil 1 0W40 is considered a very good oil, but I haven't much about Mobil's 0W30. What do you think?

MKenM

Can't tell you about 0/30 but I run 0/40 in my MB as that is the recommended oil for the car. Although it probably would not hurt Chevrolet says if you live in a climate where the temperature is -20F then 0/30 is recommended. If you don't get that cold Chevrolet also says that if you have an engine problem and they see that you are using the wrong weight oil it will void you warranty. The fact that the oil is not warm enough after 8 miles may be a problem that you will have to live with or not.

JCOA

Should have mentioned it is a 2007 Z51. I was wondering if the oil cooler in the radiator is causing the long oil warm up times. Maybe getting a thermostatically controlled oil cooler would be better in this circumstance and at the track.

JCOA

I am sure my situation isn't normal. We do get in the negative double digits here, but the corvette isn't usually out below 30 degrees. My wife's car uses 0W40 and I use it in my Toyota, even though it specs a 5W30. But when the temps get down in the single digits, it likes the 0W40 better. I am planning on trying the 0W30 at some point in the Toyota, but summer is coming.

Rebel 1

Only oil i use is Mobil1 0W-40. Has 1000 Phos. 1100 Zinc




.

MKenM

Sounds like vitamins for the car.

Rebel 1

Vitamins....yea you could call it that.

cclive

I don't think it will make any difference unless it is actually cold inside the garage when you start the car. For engine oil, cold is more like 0 degrees or below. At 30, 40 or 50, I don't think there will be any difference between a 0W and a 5W.

CBRXX

I thought this was interesting about the multi-vis oil.
https://themotoroilevaluator.com/mem...iscosity-oils/