Dwayne,

I think there are too many variables involved in order to provide a realistic answer.  I'm going with my SWAG (scientific wild ass guess) on this one to say somewhere between 5 and 50 yards.

Seriously though, if you feel that you are not getting enough performance (distance) out of your driver with the YS 6 shaft, then your only true option to find out how much you could gain is to get fit.  I know you have said there are no fitters close to you, but your options are either travel to see a fitter or never know the real answer to your question.

Whatever you choose to do, best of luck!

There are so many factors that go into play when considering distance off a driver so determining how much you may be affected is nearly impossible without knowing other conditions of your swing.  Things like length, weight, flex, kickpoint and torque are all important factors.  Us fitters can generally recommend an appropriate shaft after looking at your clubhead speed, ball speed, launch conditions, spin rate and accuracy with a particular shaft.  We know what type of shafts may benefit you after considering these numbers.  There are good reasons why Titleist offers multiple stock shaft options and other companies are following along.  Getting to an authorized dealer and fitter is your best option to really discover your potential distance.  But to approximate your distance loss with an inappropriate shaft, I would guess anywhere from 5-20 yards, if not more is certainly not out of the question.

50-80

My answer: You're far more like to hit it better (i.e. longer and straighter) with the right shaft than with the wrong one.

WW

This is an excellent question Dwayne, I wondered the same thing a while back.  I bought my 913 D3 based on a swing speed meter at a golf retail chain and the salesman concluded that this particular shaft was good choice for a senior.  It didn't take long for me to find that I was hitting a shaft that was totally wrong for me.  I did not know at the time about proper fittings when I bought the driver and a fairway wood, and I knew nothing about TrackMan.  So I made a five hour drive to a Titleist fitter.  We base lined the 913 driver and shaft performance that I had bought, using TrackMan.  Then the fitter had me try five shafts that he felt would be an improvement, and were they ever.  With the original shaft my shot dispersion was awful, the club head was never squared up due to too much shaft flex.  Once we locked in on the shaft that performed best with my swing and actually felt the best we compared the old to new and TrackMan showed that there was a 20 yard increase in distance, and the dispersion was a nice tight circle.  Went to a different fitter and another session on TrackMan.  Ran through the same drill and spent the $160 for the right shaft.  On the course the new shaft brought my game back where I was hitting fairways where I wanted and getting into better scoring position.  And... hitting Pro V1x's rather than range balls added even more distance.

Then the 915 came out.  Went back to my fitter and asked his opinion about the new club.  He said let's hit a few and see what you think.  TrackMan showed an additional 5 yards with the 915 D2 and the standard Aldila Rogue Stiff.  That shaft just felt a little better than the one that I had, an Aldila Voodoo Stiff.  I was hitting a lower trajectory, a little less spin, shot dispersion stayed about the same.  So I bought the 915.  He pointed out that if I discovered that the old shaft was better that I could swap them out if needed.

I can still  make a bad drive, that won't go away, but my bad drives are one or two a round and they usually aren't all that bad.  I have played 14 rounds this year and my handicap index is at 9.6 and trending down.  I have more confidence off the tee these days now that I'm gear'd up with good equipment, now it's all about me and making the swing.

I'd suggest that if you think you have the wrong shaft, find a fitter and find out for sure.

Dwayne,

I have a swing speed of 115 and a lot can go wrong if using the wrong shaft. I started to work with my swing coach four years ago and my swing speed was 105 at the most and didn't really think about it until a couple years later when I found out my driver wasn't going as far as it used to. I went to a friend who's a fitter that had trackman and my spin rates were through the roof, 3900 rpm on a driver. I went up to a 6.5 Project X Black tour and that cured my problems. I carry 280 now compared to the 260 before and with the roll out I get up to 300 yards and 2300 rpm of spin.

I wouldn't really trust the GC2 numbers because god forbid someone messed with the settings. Trackman fitting systems are usually the way to go because you can match the numbers to what you are seeing.

Hope this helps.