Was this a stupid move or am i paranoid

[sonic370]

First i admit it's all on me...anyway to the point.. from day one iv'e always used
Mobil 1 oil and filter for my 370. and had no issue's at all meaning no oil burning.

so when i reach 35,000 i purchase an extended warranty for my car just in case
because i plan on keep it until at least 75,000, and it was only 995.00. i mean one steering wheel lock and it almost pays for it's self. anyway back on point
salesman say's oh by the way it also comes with a years worth of free oil changes. i think great deal. so fast forward iv'e gotten 2 free oil changes since
i bought the warranty and i think nothing of it until today when i check my oil
and it's down about 1/4 quart. i know that's not much but to me it is...

so i call dealer and ask service tech what kind of oil where they putting in my car. and he says they use regular mobil 5w20.. i know don't flame i should have made sure what was going inside my ride.....sorry to ramble but would this make the car start to burn a little oil. which is more than it ever did.

again sorry to ramble but it's got me to thinking...did i screw up or not to worry....