i always bring in my own 3 quarts of mobil1 for an oil change and tell the dealership not to top off as i will add another half quart later. while checking the oil level before adding to a recent oil change, i noticed petrol smell to the dipstick oil. does this mean the mechanic just kept my mobil 1 and pumped in whatever dyno oil they had? the level does come to the expected halfway between min and max. does dyno oil smell like gasoline? mobil 1 sure doesn't smell like whatever's in my car.
No, neither dino or synthetic should smell of gas (when new). After a few cold starts however then you will get some fuel contamination of the oil, so yeah this does mean the oil may have a slight smell of fuel to it. If the oil was just changed however, then the amount of fuel contamination should be minimal. Did the oil look new?
oil seemed pretty fresh. certainly not as dark as pre-change oil. i did drive about 400 miles before checking the oil. i just don't recall ever smelling such a strong gas smell to the dipstick.
why wait 400 miles to top it off? if you have your dealer only put in 3 quarts I would drive home immediately, turn the engine off and allow a few minutes for the oil to settle back down and top it off.
i'd just been busy taking a couple trips since the oil change. and as i understand it, having the oil level halfway between min and max is perfectly fine as opposed to overfill being potentially detrimental.