Answer: I’m going to answer your question, but I have to admit that there is no scientific evidence and very little logic to justify my answer.
Since your car is out of warranty there are no implications there. I also think that most knowledgeable enthusiasts would agree that any high quality synthetic oil would suffice, and would likely be less expensive than Mobil 1 which is at the higher end of the price scale. So one might think that I would suggest that switching brands might be a good idea. But I don’t, and here’s why.
Mobil 1 is acknowledged as a very high quality synthetic motor oil, and presumably you haven’t had any problems with the engine that are related to the lubrication system, indicating that the Mobil 1 is doing its job. This is not to say that other comparable oils would not do just as well, only that the Mobil 1 is performing as expected.
Let’s assume that you change your oil twice a year, and let’s assume that you could save $2.00 per quart on comparable synthetic oil. Your car requires 6 quarts of oil (assuming that you change the filter) with each oil change. That represents a savings of $12.00 with each oil change, or $24.00 per year. For the cost of a few Cinnamon Dolce Latte Macchiato Grandes, why take a chance?