considering if, else if, else statements when writing code (java)

I wrote a program that takes the sum and range of three integers in Java. my program has several if statements for finding the range (distance between biggest and lowest integer). I was wondering if my "if statements" are the most efficient way to go about finding the range, and if not, then how could I make my "if statements" more efficient for my code, and what are some things I should consider when I am writing if and else if, and else statements in Java.

    Scanner in = new Scanner(System.in);

    System.out.println("Enter an integer value for n1");
    n1 = in.nextInt();
    System.out.println("The (integer) value for n1 is " + n1);

    System.out.println("Enter an integer value for n2");
    n2 = in.nextInt();
    System.out.println("The (integer) value for n2 is " + n2);

    System.out.println("Enter an integer value for n3");
    n3 = in.nextInt();
    System.out.println("The (integer) value for n3 is " + n3);

    sum = n1 + n2 + n3;
    System.out.println("The sum of n1+n2+n3 = " + sum);


    if(n3< n1 && n3<n2){
        if(n2<n1){
            maxRange = n1-n3;
        }
        else if (n2>n1){
            maxRange = n2-n3;
        }
    }

     if(n2<n3 && n2<n1){
        if(n3<n1){
            maxRange = n1-n2;
        }
        if(n3>n1){
            maxRange = n3-n2;
        }
    }

     if(n1<n2 && n1<n3){
        if(n2>n3){
            maxRange = n2-n1;
        }
        if(n3>n2){
            maxRange = n3-n1;
        }
     }


aMean = (n1+n2+n3)/3;

System.out.println("the arithmetic mean is : " + aMean);
System.out.println("The maxRange is :"+ maxRange);


}

}