It will run even better if you add an EAT chip with at least 91 Octane! When my '90 535i had the stock chip it ran 87 Octane with no problems, it's what was the required fuel octane. Now with the EAT chip I run about 92 Octane and the chip manages to produce more horsepower and torque as it optimizes the timing for higher octane fuel. I also get better gas mileage with the EAT chip.