Mobil 1 Delvac is one of the best oils for diesels. I have been using it in my vigo 2014 and 2011 models. I was keeping oil change intervals of 10,000kms.
Issue with Delvac 1 is its cost and availability.
But if you see the specs of Delvac 1 and Mobil 1, these are almost identical. I have a grande as well. So now I am planning to stick to Mobil 1 both in Fortuner and Grande. Mobil 1 is slightly economical and has better availability. Also it is 0W-40 i.e., a slightly better viscosity for new engine. Cheers,