Mobil 1 oil weight

[Grant Lenahan]

Guys - ignore those charts.
Think oil flow.
Think about the distribution fo time from cold to hot.
Read the viscosity ratings at 40 and 100 deg and extrapolate.
Those charts are obviously wrong.  Note also how every manufacturer is 
moving to thinner and thinner oils.  We're learning, slowly.

Grant
On Apr 30, 2007, at 1:50 PM, Al Streicher wrote:

> I am a little confused with those charts from SJM. In column A is 
> listed a
> 10W-30/10W-40 oil as being "Energy conserving oil". Column B also has
> 10W-30/10W-40 as just multi-grade oil. What is the difference?
> I live in the tropics, temps run from 65-98 degrees.
>  My car is a 1990 80 Non-Q, 4 banger. 60K on rebuilt engine. (208K)
> I currently use Castrol 20W-50 Synthetic based on the older chart.
> Now do the arrow points on the end of the graph indicate going to 
> infinity,
> as opposed to the bar that ends specifically at a temp.
> If they mean beyond, then I could use the following:
> 5W-30, 5W-40, 10W-30 and 10W40 in the energy conserving class.
> In addition I can use these multi-grade oils:
> 5W-50, 10W-50, 10W-60, 15W-40, 15W-50, 20W-40 and 20W-50.
>
> Since the temps never go below, say 50 degrees, I could use a low 
> 5W-XX..
> Am I correct??
>
> Interesting subject.
>
> Regards,
> Al Streicher
> Mililani, HI.
>
>
> ----- Original Message -----
> From: "Ameer Antar" <antar at comcast.net>
> To: "Taka Mizutani" <t44tqtro at gmail.com>
> Cc: "Quattro List" <quattro at audifans.com>
> Sent: Monday, April 30, 2007 4:36 AM
> Subject: Re: Mobil 1 oil weight
>
>
>> I did some reading and it looks like Mobil 1 and Penzoil both are GF4 
>> rated
>> (and PAO-based). I've had trouble finding anything with GF5.
>> Unfortunately,
>> none of the manufacturers give the rating on 40 or 50 weight oils, so
>> they're
>> probably not GF4. I've had no trouble with 10w30: no clatter, no 
>> leaks,
>> but
>> then this is a rebuilt engine. I think I might stick with it since 
>> the 40
>> weight is not as highly rated.
>>
>> I just took another look at the oil grade chart on SJM's site and 
>> noticed
>> that
>> the chart for the '95 S6 looks very similar to the chart for the 
>> 5kt/tq.
>> What's
>> interesting is that the '95 shows a second group for "Energy 
>> Conserving
>> Oil".
>> Here they say it's ok to run just about anything all year round: 5w30 
>> -
>> 10w40.
>> I think this shows that oil has changed quite a bit over the years. I
>> think
>> almost all of the oils are Energy Conserving except for the heavier
>> weights, so
>> with that and the fact that it's fully synthetic, I think 10w30 is
>> probably
>> fine for the summer. I might switch to 5w30 or even 0w-30 during the
>> winter. I
>> think the main thing is that the second number, which reflects the
>> viscosity at
>> temp is correct. The first number just says how easy it is to flow at
>> startup,
>> which is definitely important for winters here in the NE.
>>
>> So I think the lesson learned is: 10w30 for warm weather and 5w30 for 
>> cold
>> as
>> long as the oil is EC rated. But if you have noisy lifters or weak 
>> seals,
>> thicker oils will help.
>>
>> -Ameer
> .snip.
>
>
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