Best oil for GM-Isuzu V6 diesel (Common Rail)

[Celes]

Hello
Been wondering, which oil would suit my engine best?
I drive a 2003 Opel Signum with an Isuzu V6 turbo diesel engine. I call it baby Duramax According to the owner's manual the oil should meet or exceed ACEA A3 standards. The manufacturer recommends 5w-30 for extended intervals, but I find this oil too thin. I often drive fast and hard, but not all the time.
This particular engine is known for high oil temperatures, close to 140°C (284°F) if driven flat out for about 10 minutes. I am currently running on Mobil 1 Rally Formula 5W-50 and it's been good so far. Had it in when I was blasting on the German autobahns It's due an oil change now...3months and 6k miles

What do you guys recommend for an aluminum engine that runs at high oil temperatures?

 

[addyguy]

We have no idea what oils you have access to......

 

[Celes]

There's always the good old ebay

 

[willix]

284F is getting up there, Being able to drive flat-out for 10 minutes is above and beyond the call of duty. Maybe not. I'd stick with the M1 if it meets the standard. We don't get the M1 "rally formula" here and I am very curious. With out qualifying knowing anything other than heat kills, the manufacturers recommended oil is the status quo for warranty purposes but a 2003 is out.. I would consider modifying the oil cooler and bring that temp down with a hearty well exposed/vented additional oil cooler.

 

[Celes]

You can easily drive flat-out for 10 minutes in Germany, but it depends on traffic obviously. I never drove that fast though.

I've asked a few people around here about an additional oil cooler and no one seems to be brave enough to modify my car's oil cooling in any way..."way too risky" "too expensive"

The engine's done close to 120k miles and purrs like new.

 

[addyguy]

6k oil changes must get expensive over there?

 

[Celes]

The manufactures allows 30k oil changes if using the longlife stuff. Way too long...for my driving style and 5w-30 oil.

 

[willix]

Whats to risk. http://www.amazon.com/Flex-a-lite-3952-Engine-Oil-Cooler/dp/B000CNJB82