A new insurance offering from General Motors could be more than $1,000 per year more expensive than its competitors, according to a new report from ValuePenguin.

GM will be offering its own auto insurance through its OnStar services brand. The insurance is currently available in Arizona, and GM plans to slowly roll coverage out to other states starting in 2021. GM’s OnStar Insurance is usage-based and sets its rates according to the driving behaviors of policyholders, according to ValuePenguin.

ValuePenguin’s study found that OnStar Insurance was usually one of the most expensive options for both full and minimum coverage – especially if the driver didn’t own a GM vehicle.

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While any driver can sign up for OnStar Insurance, only drivers of GM vehicles that were manufactured in 2015 or later and that have OnStar capabilities can qualify for OnStar Insurance’s driving discounts, since the OnStar system is used to monitor drivers’ behavior and set rates accordingly.

Moreover, OnStar Insurance could be much more expensive for drivers who don’t qualify for discounts. Indeed, even drivers who earn discounts could pay more for OnStar Insurance than they would with another company, ValuePenguin found.

“Upon comparing the cost of car insurance for a driver of a Chevrolet Equinox with OnStar and a few of its largest competitors, ValuePenguin found OnStar Insurance was usually one of the most expensive options for full and minimum coverage,” the report said. “In Phoenix, OnStar Insurance offered the most expensive car insurance. For minimum coverage, it was over $1,000 more expensive per year – for the same vehicle – than Farmers. While OnStar estimates that its customers could see up to a 20% reduction on their car insurance policies by signing up for coverage, this discount wouldn’t improve the company’s ranking.”