foreach loop geeft extra ongewenste resultaten

<?php

  $mysqli = new mysqli('localhost','root', '', 'availabilitycalendar');
  $sql = "
    SELECT rentaltype.VehiculeType, vehicules.VehiculeNr FROM vehicules, rentaltype WHERE rentaltype.Id = vehicules.VehiculeType ORDER BY vehicules.VehiculeNr ASC";
  $result = $mysqli -> query( $sql);     
  if (!$result) {
    printf("Query failed: %s\n", $mysqli->error);
    exit;
  }

  echo '<pre>';
  print_r($result);
  echo  '</pre>';echo "<br><br>";

  while ($vehiculeCode = $result -> fetch_array()) {
    $new_array[$vehiculeCode['VehiculeType']] = $vehiculeCode;
    $new_array[$vehiculeCode['VehiculeNr']] = $vehiculeCode;
//    echo( $vehiculeCode['VehiculeType'] . "_" . $vehiculeCode['VehiculeNr'] . '<br>');
  }
  echo '<pre>';
  print_r($new_array);
  echo  '</pre>';echo "<br><br>";

  $mysqli -> close();
  echo "<br><br>foreach loop<br><br>\n";

  foreach( $new_array as $row){
    echo $row[0] . "_" . $row[1] . "<br>";
//    echo $row['VehiculeType'] . '_' . $row['VehiculeNr'] . '<br />';
  }

?>

Output
eScoot_2104001
eScoot_2104002
eBike_2104003
eScoot_2104004
eScoot_2104005
eBike_2104006
eScoot_2104007
eScoot_2104008
eScoot_2104009
eScoot_2104010


foreach loop

eScoot_2104010
eScoot_2104001
eScoot_2104002
eBike_2104006
eBike_2104003
eScoot_2104004
eScoot_2104005
eBike_2104006
eScoot_2104007
eScoot_2104008
eScoot_2104009
eScoot_2104010