I have a 1994 530ia with a Dinan Chip installed. Although I do have to use premium gas, my gas mileage increased about 10% with the chip under normal driving conditions. However, based on the rave reviews about the Conforti chip, I am thinking about buying pne for my car. Any experiences with increased/decreased gas mileage with the Jim C. chip? Also, any negative experiences with the chip? Thanks in advance.