I use Mobil 1 5w30. Change about every 100 hours or once/year.
Used Mobil 1 in my Benz diesel for 2 years, changing once/yr or about every 6-7k miles. Last time (3rd on synthetic), I switched to Shell synthetic 5w40. Can't find much Mobil 1 10w40. There's some occasional 0w40 that I could use for it. The manual says 10w40 for it. The first Mobil 1 was a 50/50 mix of 15w50 and 5w30 in an attempt to get 10w40. It seemed to use a bit more oil with this blend, not a whole lot, just a bit more than its qt/1000-1500 miles. The 2nd change was some 5w40 "SUV and truck" Mobil 1. Used normal amount of oil with it. Have only added about 1/2 qt so far during the run on Shell synthetic.
Ralph