Mobil 1 oil weight

[Grant Lenahan]

On Apr 30, 2007, at 7:51 AM, Taka Mizutani wrote:

> That's the part I disagree with- with the light weight oils in the 
> I-5, I get LOUD lifter clatter on cold starts and oil consumption.
Neither of which correlates very well with engine wear.  In fact, if 
its typical I5 oil loss through the valves, the hgiher loss means 
BETTER lubrication and protection.

>
> I don't get that with the heavier oils.
But why are either important - that's the issue.
>
> I also don't agree that 0W oils are fine- the anti-shear properties of 
> the super-lightweight oils they spec these days is not so good.
Shear is not a clearly defined term in lubrication - thrown around a 
lot, but not well defined.  Flow = lubrication.  Now flow = death.

>  I would be very leery of running stuff that light in a really high 
> performance engine. I know that Corvettes and Porsches as well as AMG 
> Mercedes run these 0W oils, but I doubt anyone is using the stuff in a 
> track car.
I agree that if you will see sustained oil temps > 100 deg C, and 
almost no warm-up time, thicker oils have some benefits. I wrote that 
very clearly. I will wager none of us qualify.  1 track day and 90 
commutes is still mostly cold driving.

> Considering that at least the LS7 as the GT3 motors are really, really 
> high-strung, I wouldn't trust that light stuff to keep the bearings 
> lubed.

I do in my M96 motor.

I also ran 5W30 >> 200k miles in my 2 I-5s.

Grant
>
> Taka
>
>
> On 4/30/07, Grant Lenahan <glenahan at vfemail.net> wrote:
>> You also didnt reference what kendall, base stock type, flash point, 
>> VI
>> rate nor ACEA acceditations.
>> So there's not much to go on in your post.
>>
>> Read the articles I referenced first.
>>
>> I dont believe the tolerances are THAT bad on a well maintained I5. I
>> cant speak for yours in particular of course.
>>
>> I dont care what you personally use, but I do want to overcome the
>> persistent myth that 5W30, 5W40, 0W-30 and )w40 are too light. They 
>> are
>> not.
>>
>> Grant