Issues grabing data using XMLReader and CURL

I have a feed that contains over 10000 vehicles and is about 300 mb and trying to grab and display the name and the price of each vehicle.The problem is it displays all the data in the feed.

Below is the feed that i used

 <vehicle>
      <type>Double Cab </type>
      <price>19.5k</price>
      <model>GTX</model>
<descrip>sdsadasdasdsa</descrip>
    </vehicle>

 <vehicle>
      <type>Cruise </type>
      <price>78k</price>
      <model>Ultra</model>
     <descrip>sdsadasdasdsa</descrip>
    </vehicle>

 <vehicle>
      <type>Jeep/ Wagon </type>
      <price>2k</price>
      <model>Body Kit</model>
      <descrip>sdsadasdasdsa</descrip>
    </vehicle>
 

I’m using the below code.

$url = 'vcfeed.php';

$xname ="test";
$xPassword ="testuser";

$post_data = array("username" => $xname, "password" => $xPassword");
$ch = curl_init($url);

$c[CURLOPT_POST] = true;
$c[CURLOPT_POSTFIELDS] = $post_data;

foreach($c as $k=>$v){$c[$k] = $v;}
curl_setopt_array($ch,$c);

$xml = curl_exec($ch);

curl_close($ch);

$z = new XMLReader;
$z->open($xml);

$doc = new DOMDocument;


while ($z->read() && $z->name !== 'vehicle');


while ($z->name === 'vehicle')
{

    $node = simplexml_import_dom($doc->importNode($z->expand(), true));


  echo $node->model;
  echo $node->price;


    $z->next('vehicle');
}

 

Although i have used  

echo $node->model;
  echo $node->price;
 

It doesn’t show those 2 values for each result. Can someone tell me what am i doing wrong here?