Mobil 1 oil weight

[Al Streicher]

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.