You can run any fuel as long as it has the right oil mixture. But you dont have to worry about that because about 98% of all car fuels use the right mixtures. Trinity monster is a good brand, has a good smell too. Powermaster is another good one, has a awsome smell and O' Donnel which gives you the most power but has the most awful smell there is. and no, any other fuel will not void warrenty. Only if it needs to rebuilt there not gonna do it for free your gonna have to bust out the cash. Other than that any fuel will work.