A Toronto couple recently learned the hard way that Canada’s transportation safety rules don’t require vehicles to come with tire pressure monitoring equipment.

What tipped them off was a tire blowout that happened while they were driving in the U.S. Christinea and Surujpaul Singh took their 2016 Subaru Forester to a local dealer to have the tire replaced, where the service technician shared their surprise at the lack of a low-tire-pressure warning from the car before the tire blew.

What they learned through Subaru Canada was that tire pressure monitoring, or TPMS, is not mandatory on cars sold in Canada.

And that is surprising, because TPMS has been mandatory in new cars sold in the U.S. since 2007 and the Canada Motor Vehicle Safety Regulations, the federal legislation that dictates what safety features must be included in cars sold here, is normally updated to reflect regulatory changes that occur south of the border.

But Transport Canada has never added TPMS to that list of rules, leaving manufacturers to offer it as they see fit, often as an option in higher-end trim levels.

Subaru is one of the manufacturers that has opted to not make the feature standard, and the Singh family says that’s disappointing given their experience.

“It was traumatic actually, because our car almost flipped over and we managed to veer to the side of the road with no tire on,” said Christinea. “We were under the impression that there was a tire safety warning.”

Subaru cites cost as the reason it doesn’t install TPMS in its Canadian-market vehicles.

“Transport Canada’s research has not identified that TPMS provide any potential safety benefits to Canadians,” Julie Lychak, public relations manager for Subaru Canada, said in a statement. “Subaru vehicles are equipped with features to meet the regulations and unique demands of each market where they are being sold.”

(via CTV News)