A class action lawsuit has been filed in Pennsylvania against BP Lubricants USA and used car dealer CarSense, alleging that the defendants sell a written warranty that violates the Magnuson-Moss Warranty Act because the warranty contains an illegal tying provision.

Citing alleged abuses of the Magnuson-Moss Warranty Act (MMWA)—which prohibits tie-in sales provisions that effectively lock consumers in with warranty issuers by forcing them to buy an item or service to continue coverage—the complaint alleges the defendants sell cars with warranties that require purchasers to use only premium Castrol motor oils.

When accessorizing your vehicle with aftermarket parts, your warranty claim cannot be automatically denied, nor can your warranty be voided, if you install non-OEM parts in your vehicle. The burden is on the dealer to prove the aftermarket parts caused the failure.

The plaintiffs claim this is the exact conduct the MMWA was enacted to fight. While they believed they were paying for peace of mind when they initially bought their car and warranty, the plaintiffs claim the defendants instead forced them into a one-sided contract over which they would ultimately end up paying more for repairs than they had bargained.

“Under the MMWA, [the defendants] have created an illegal tying arrangement by requiring [the plaintiffs] to change the motor oil in their vehicle every 4,000 miles of four months with only Castrol products,” the lawsuit alleges. “[The plaintiffs] are paying more for Castrol products than what they would pay for substantially similar or possibly superior motor oils.”