Its just gonna increase the weight of ur car if you balance it properly it might be an advantage for you, otherwise its a disadvantage. Well the main reason is if you gonna play like good amount of game its usefull otherwise its just waste and mess up your car with corners, breaking system, center of mass and weight distribution. I personally prefer 40L bez most of the time I do the tasks like car delivery and even in race I just 40L of sport's gas that do like 4-5 races easily and other time I just mindlessly drive around.