When Ram originally published the cargo capacity for its van, it simply did a direct conversion from the European rating of 15 cubic meters to 530 cubic feet. However, that didn't take into account the standard way internal measurements are calculated for the US.

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Companies that buy vans often prioritize volume when choosing a new vehicle. With the change in measurement, the ProMaster's capacity drops from second to third place in the segment. According to AN comparing the largest version of each van, the Mercedes-Benz Sprinter leads the category with 547 cubic feet of storage, followed by the Ford Transit at 487 cubic feet. The revised ProMaster should still have a significant advantage over the Nissan NV that offers 323 cubic feet of capacity.

Hyundai and Kia say they will offer affected customers a rebate in the form of a refillable debit card with the value based on how many miles the owner has driven and the average price of a gallon of gas in their area, along with a 15 percent premium. While that would amount to less than $100 for many customers today, Hyundai and Kia say they will add to the debit cards as the owners keep driving; the companies also vowed to compensate previous owners of the affected models who had sold their cars.