Is my Ford factory warranty valid if I have the oil changed at a local garage?
With each vehicle purchase, Ford offers a limited warranty to protect drivers in the event of a manufacturer part failure. For new and pre-owned models there are different coverage available depending on various factors. The important thing to note about these warranties is what actions void them. While there is a list of actions that void your Ford Warranty, such as the use of additives not approved by Ford or environmental damage, things such as keeping up on your regularly scheduled maintenance do not void your warranty.
If you choose to take your Ford a local auto repair shop, as long as the mechanic is using Ford approved products, your warranty will not be voided.