(Canada, US, idiomatic, often computing) It may work differently in your situation, or be different in your experience.
The battery lasts a day in my phone, but your mileage may vary.
(Canada, US, idiomatic) Used to express a possible difference in taste: this is just my opinion, your opinion may be different.
I think that red dress looks really good on you, but your mileage may vary, of course.
Your mileage may vary, and I don’t want to sound dogmatic, but I recommend you unit tests, and see how you get on. Source: Internet
Your mileage may vary, but usually, as Bart Simpson so eloquently put it, “Knife goes in, guts come out.” Source: Internet
Your mileage may vary depending on your ear size. Source: Internet