The oils are probably OK. Until '01, 5W30 was what was recommended. Nothing changed in the engines, so it seems that the 5W20 requirement is just to help the vehicle's economy. I'd run Mobil 1 except that IF you have a problem, Ford can use that as an excuse to not honor your warranty.

If your dealer has "blessed" it, you need to get it in writing &/or keep your receipts if they are doing the work. Ford- not your dealership, warrants the vehicle.