I now have about 1,000km on my new-to-me DT. I am getting between 3.3-3.6km per 100km, depending on the type of riding I am doing, which I am happy with.
About 200km ago I replaced the stock exhaust with the MIVV slip-on exhaust that I got with the DT. Installation went fine and fit is good.
My observations:
Good:
* much of the shuddering I was getting on take off before, which I thought was due to the stock clutch, has disappeared. Still there a little, but no where near as noticeable as before. This was a huge, but welcome, surprise.
* the torque/acceleration curve has smoothed out --> used to have a lull in acceleration from approx 25-40km/h, then the 'real' acceleration kicked in after that. Now the acceleration is more of a steady curve without the lull.
* has a nice, deep growl at idle and slow speeds - not too loud. N.B. Still can't really hear it through the helmet when the speed rises over 60-65km/h.
* lighter than the stock can - think approx 2-2.5kg lighter.
* looks good - smaller and classier looking
Not So Good:
* the DT is not quite as fun to ride now. 0-80km/h times still the same, if not a fraction quicker (just counting in my head), but I now don't experience the lull followed by the kick in the pants at 40-45km/h that used to push my head back!
* I tightened the 2 main bolts that attach the slip-on to the scoot and have been checking them each week or so, but I neglected to tighten the little allen key headed bolts that attach the metal heat guard. Was out riding the other day when I heard a tinkling sound. Slowed down, looked back, and saw my heat guard hanging by a single bolt. Replaced two missing bolts and will check those from now on also.
All of this is just my subjective experience, so no guarantees that yours will be likewise if you install this or any other aftermarket exhaust.
I have also removed the screen completely to see what effect that has. Back to riding a naked scoot and enjoying the nice clean, non-buffeting airstream again. I also got a sport screen with the DT, so will try that next.
Only other planned upgrade I will do is 14gm sliders at the next service/transmission check.
Ride safe.