please help..
if dynamic compresion ratio is :
4.2:1 what octane gasoline do I use ?
4.8:1 what octane gasoline do I use ?
5.4:1 what octane gasoline do I use ?
6.0:1 what octane gasoline do I use ?
6.6:1 what octane gasoline do I use ?
7.2:1 what octane gasoline do I use ?