Hi,if its proper biodiesel you wont have to do any mods to your vehicle,the only time mods need to be done is if your running svo (straight vegatable oil),like yourself i started out making 1 litre,get a jam jar and place 1/3 of water in it,then pour the same amount of bio into it,there should be little or no emulsion (creamy coloured bio),if there's a definate split (water on the bottom) bio on top then the bio is ok to use,hope this helps you,feel free to get in touch if i can be of anymore help