I have an 06 DR650SE, with 6,000kms and a Staintune exhaust on that I've bought in Australia to do the ride back to the UK in a year or two so fuel economy is important for me. It's running fine as far as I can tell and seems to be getting decent fuel economy at around 24kms/L when out of town. I've read about people doing a dynojet and airbox mod on DRs but I'm unsure on a couple of points which hopefully someone can clear up: 1. Does this mod make the bike more or less fuel efficient or is this not altered? 2. Any likely problems with the modified bike at high altitude? 3. What exactly is involved in doing the mod? 4. What are the benefits?