I don't think the standards of the OEM filters are that high. Only spec I know of that a vehicle manufacture can follow is USCAR-36 (which Ford follows for Motorcarft oil filters), and it's not really that tough to meet. And the manufactures who don't follow USCAR-36 can probably make up any specs they want, which doesn't necessarily mean they will be that good.The Denso rep says this: Keep in mind that this is an aftermarket filter, the standards are not as high as the dealer (OEM) filter.