Recomended oil for Toyota 1KD-FTV engine?

I found the best suited oil for the 3.0L TD 1KD is castrol RX super, this oil environments the manafactures specs. RX super is 15W 40, and would not be suitable for environments that reach -7degrees like alpine regions. RX super has good detergent properties to keep your engine clean. althow Toyota recommends oil change at 10 000k intervals, most people would suggest to change at 5000k instead. the engine should take 6.9L of oil with a filter change