Download (DOS/Win3.1 version) Download (Win95 + version) To determine the best ratios to use in your car at a particular circuit we have a choice of two tools to help you: Ratio Chart website Our Interactive web-site allowing you to produce customised ratio charts is now fully functional. Please visit www.hewland-chart.com The site allows you to produce an individual ratio chart customised to your requirements for any standard Hewland gearbox. In addition there is valuable advice on how to optimise your cars performance using the ratio chart, and techniques for changing gear. Ratio Calculation Program The Hewland Ratio Calculation program is supplied free of charge and can be freely distributed provided it is done so in its current form without any modifications. Click on the download button above to obtain the latest version. This is a self extracting zip file, which when run will extract two files (install.exe and Ratios.ex_) to the A: drive, so please ensure you have a formatted floppy in your A drive. Once extracted, run A:\install to install the program. On-line instructions will guide you through starting and running the program.