Compare tail recursion, list folding and classic approach

TestTailRec.scala

package org.halfcup.scala

import scala.annotation._

object TestTailRec {
  def main(args: Array[String]): Unit = {

	val list = List("one", "two", "three", "four", "five", "six", "seven", "eight", "nine","ten")

    def maxWidth(s: List[String]) = {
      var maxLength = 0
      for (str <- s) {
        maxLength = maxLength.max(str.length)
      }
      maxLength
    }

    @tailrec
    def maxWidthRec(s: List[String], max: Int): Int = {
      s match {
        case Nil => max
        case _ => maxWidthRec(s.tail, max.max(s.head.length))
      }
    }

    def maxWidthFold(list:List[String]):Int = {
    	return list.foldLeft("")((s1, s2) =>
          if (s1.length > s2.length) s1
          else s2).length
    }

    for (i <- 1 to 100) {

      val t3 = System.currentTimeMillis;
      for (i <- 1 to 1000000) {
        val max = maxWidth(list)
      }
      val t4 = System.currentTimeMillis - t3
      println("Simple: " + t4)

      val t1 = System.currentTimeMillis;
      for (i <- 1 to 1000000) {
        val max = maxWidthRec(list, 0)
      }
      val t2 = System.currentTimeMillis - t1
      println("Tailrec:" + t2)

      val t10 = System.currentTimeMillis
      for (i <- 1 to 1000000) {
       val max = maxWidthFold(list)
      }
      val t20 = System.currentTimeMillis - t10
      println("Fold: " + t20)

    }
  }
}

Sample output:
Simple: 221
Tailrec:182
Fold: 81

On the other hand I get quite reasonable result when I run it from terminal:
Simple: 46
Tailrec:53
Fold: 47