Creating width is not a matter of how far you can move the clubhead from your body, it is how far you can distance the club handle from your chest. Creating width is the first step to increasing distance with your driver.
What happens to the driver after impact? If you intend on increasing speed, your arms will allow the club to re-hinge. If you prevent this, you increase tension, which slows down your swing.
Step 1: Create Width. Step 2: Push away - transfering force away from the direction of the swing - not up. Step 3: Re-hinge the club; this requires relaxation, which increases speed.
Now that we know where Impact Position is, let's train our swing from here. This will give you a strong sense of how to get to the ball.