How many miles in between for a synthetic oil change

I've been told that 100,000 miles is typical~....but personally would have to check the levels...guess I'm nervous~

Tom...you da man~ MINI said 100,000 miles...personally was gobsmacked and I'm like "no way" but that's what the owner's manual says~ you know this oil is "slippery" more so that a person cannot switch to synthetic, but must have had synthetic all along..else you get leaks~...is what they say is the problem...personally would never do that. but things on my MINI go on TRUST...no temperature gauge...voltage or any other data....the thing operates on faith~ I can check to see if this is horse-puckey.....I can suggest that no harm comes from checking the oil level~ let 'er ride till a change in engine sound makes you want to check it~ never have I seen an oil leak from synthetic, like the critics say~ okay make it ten~ sensible approach...NOT going on FAITH like MINI has me doing~ sadly the engine never comes up to operating temperature and has stayed at pretty much 40,000 miles...so this may NOT be our example for oil changes~

If it's full synthetic and dectrose oil or how ever u spell it it can last 100 k miles if not driven hard If drove right and not abused ut can I would recommend 1 about every 80k or once it starts skipping between gears but it is amazing how good they do

5,000 miles on my 2015 Forester but I keep my cars for a long time.