new Text:td_fuel[MAX_PLAYERS] = {Text:INVALID_TEXT_DRAW,...}; // Add the little extension!

public OnPlayerSpawn(playerid)
{
    TextDrawDestroy(td_fuel[playerid]);
    td_fuel[playerid] = TextDrawCreate(45,324,"Fuel: 100"); //create the textdraw at position
    TextDrawBackgroundColor(td_fuel[playerid],0x00000033); //setting an nice backgroundcolor
    TextDrawFont(td_fuel[playerid],3); //font type of textdraw
    TextDrawLetterSize(td_fuel[playerid],0.699999,1.700000); //size...
    TextDrawColor(td_fuel[playerid],0x000000ff); //color
    TextDrawSetShadow(td_fuel[playerid],3); //dropping the shadow
    return 1;
}