I gave it one star because I couldn't leave them all blank. The chip didn’t really seem to work, neither with HP nor Gas mileage. I contacted them about it, and they said to send it back for a full refund. I bought the chip along with an OBD splitter. I returned both, but my refund came up nearly $45 less than expected. I tried calling them for 3 days before finally getting through. When I did, the person was rude and argued a lot. He claimed there was a restocking fee. Their policy says a fee applies only if the product isn't in like-new condition. The chip was in the same condition as when I received it, and it was returned with all the original packaging. He kept arguing about it.