So as I see it for me I have a couple of options, I want something  
this is always available.

Here are the offerings from Mobil 1:

0W-40
10W - 40 High Mileage
15W-50

or

Castrol Edge
5W-30
They claim in their test against Mobil 1 that 8x better due to the  
fact that in their 100 hr test they beat out the Mobil 1 product:
http://www.castroledgeusa.com/#/why-upgrade/results
(they claim it better than Mobil 1, Mobil 1 Extended Performance,  
Valvoline Synpower and Royal Purple.
http://www.castroledgeusa.com/#/faq

Now mind you, I am planning on driving cross country in a month or  
two. So there is going be a lot of high heat areas, with lots of long  
hot day driving.
I can't imagine the temps to get lower than 40 degrees but could get  
as high 120 degrees.

What are your thoughts?

Rob
NY
---------------------

I was thinking of using this one since my engine will be freshly  
rebuilt as of next week:
http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_0W-40.aspx

Mobil 1 0W-40 meets key industry and car builder specifications for:

Mercedes MB 229.5
BMW Longlife 01
Porsche Approval List 2002
VW 502.00/505.00/503.01
GM-LL-A-025 (gasoline)
GM-LL-B-025 (diesel)
ACEA A3, B3/B4
API SM/CF
Exceeding industry standards and the major leading builder  
requirements is the cornerstone of the performance reserve that lets  
Mobil 1 0W-40 keep performing well after conventional oils cannot.  
Mobil 1 0W-40 provides the widest range of protection -- providing the  
extreme cold start protection of an 0W grade and the high temperature  
protection of an SAE 40 grade.

Mobil 1 0W-40
Our lineup of Mobil 1 motor oils includes a 0W-40 viscosity, which is  
the viscosity recommended by many European car builders. Mobil 1  
0W-40's wide viscosity range provides unsurpassed levels of protection  
and an overall smooth driving experience. Mobil 1 0W-40 keeps engines  
starting in Arctic-extreme cold, and it cleans deposits, sludge and  
varnish often formed in high temperature operating conditions.

http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_High_Mileage_10W-40.aspx
Mobil 1 High Mileage 10W-40

As your engine ages, seals deteriorate, oil burn-off increases and  
sludge can build up, which can all result in a decrease in engine  
performance and, ultimately, reduce engine life. Mobil 1� High Mileage  
10W-40 is designed to maximize engine performance and help extend  
engine life.

        Mobil 1 High Mileage is designed especially for engines where  
conventional oil has been used, and where these conditions have been  
experienced:
Severe Service
Extended Oil Drains
Poor Maintenance
Multiple Owners
For engines where heavy deposits and sludging exist, we recommend  
initial oil change intervals of 3,000 miles as cleanup progresses.

Mobil 1 High Mileage 10W-40 is designed for higher mileage vehicles  
and provides the following benefits:
Extra anti-wear additive helps protect critical engine parts.
Reduces the sludge and deposits conventional oils can leave behind.
Contains a special seal conditioner to help recondition seals and  
prevent leaks.
Higher viscosity formula helps reduce oil burn-off and leakage.
Meets API SL/CF
Here is something from the QA section:
I thought Mobil 1 as a full synthetic already provided the protection  
my high-mileage car needs. Do I really need to switch off Mobil 1 to  
your High Mileage product for my high-mileage car?

Mobil 1 High Mileage is designed for high mileage vehicles that have  
been using conventional oils. It's true that most Mobil 1 vehicles  
with 75,000+ miles should be in excellent condition and would not  
require some of the Mobil 1 High Mileage benefits. However, most cars  
on the road today do not use synthetic oils, so we developed this oil  
specifically for these cars that would benefit from switching off  
conventional oil.

http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_15W-50_.aspx

        Mobil 1 15W-50 exceeds warranty requirements for gasoline engines  
where an API certified oil is specified. It meets:
API SM/SL
Requirements for Diesel Powered Vehicles where an API CF or API CD is  
recommended
Provides extra anti-wear additive for older vehicles

Mobil 1 15W-50 is formulated with SuperSyn, an extra-high viscosity  
synthetic fluid, plus extra anti-wear additive to provide extra  
protection for severe service applications such as towing, hauling and  
racing. Mobil 1 15W-50 is recommended for high performance vehicles  
including turbocharged and supercharged engines where a thicker oil  
film is desired.

Mobil 1 15W-50 is also recommended for older valve train designs that  
may benefit from a higher level of anti-wear normally not required for  
newer generation vehicles. Mobil 1 15W-50 will also provide better  
anti-wear protection for higher valve spring tensions in certain  
racing engines.

On Apr 24, 2009, at 4:55 PM, Todd P Last wrote:

> Hmm, if you want more zinc-phosphorous additives, why not go with a  
> motorcycle oil?
> Like a synthetic V-twin motor oil .... after all, the VW engine  
> started out as an air-cooled engine...
> The one question would be if the lack of friction modifiers would be  
> a limitation.
>
> http://www.mobiloil.com/USA-English/MotorOil/Oils/Motorcycle_Oil_FAQs.aspx#FAQs1
>
> I've also heard of people using synthetic oil for diesel engines to  
> get more phosphorus/zinc additives.
>
> Todd
> '88 Westy
>
> Dave Arthur wrote:
>>
>> Is there an advantage to running synthetic in a WBX 2.1 over  
>> conventional
>> oil? If so what weights are being used?
>>
>> Dave
>>
>>