B18 and B20 engines call for "100 octane leaded" fuel, but this hasn't been available for quite a while. Tuning one of these engines to run on the low octane stuff they call gasoline can be tricky at best. Installing a low compression kit will help prevent pinging and other problems associated with low grade fuel and high compression. Kit includes a thicker headgasket and matching water pump seals.
This kit typically lowers the compression ratio by 1 full point. You will experience some drop in gas mileage due to the fact you are compressing the air/fuel mixture less before ignition - thus less power is developed.
