Posting values of input fields outside form tag containing submit button

Just store the values of all the input fields through jquery and submit your form through ajax on the click of your submit button.

$('form').submit(function(event) {

    // get the form data
    // there are many ways to get this data using jQuery (you can use the class or id also)
    var formData = {
        'electricity'  : $('input[name=electricity]').val(),
        'threewheel'   : $('input[name=threewheel]').val(),
        'fourwheel'    : $('input[name=fourwheel]').val(),
        'twowheeler'   : $('input[name=twowheeler]').val(),
    };

    // process the form
    $.ajax({
        type        : 'POST', // define the type of HTTP verb we want to use (POST for our form)
        url         : 'savedata.php', // the url where we want to POST
        data        : formData, // our data object
        dataType    : 'json', // what type of data do we expect back from the server
        encode      : true
    })

you are able to log and also able to error handling in your jquery.

1. Write javascript to handle submit event
2. On submit event append your input with form data
3. Submit

For reference please refer Adding POST parameters before submit

$( 'form' ).submit(function ( e ) {
    var data;

    data = new FormData();
    data.append( 'electricity', $('#elecr').val());
    data.append( 'threewheel', $('#3wheel').val());
    data.append( 'fourwheel', $('#4wheel').val());

    $.ajax({
        url: 'savedata.php',
        data: data,
        processData: false,
        type: 'POST',
        success: function ( data ) {
            alert( data );
        }
    });

    e.preventDefault();
});