Is it normal to get better economy after fitting a new slip on exhaust? I've fitted a new Megacycle slip on to my Suzuki GS500F With the stock exhaust, I'd fill up at 350K and I'd usually put in between 14.5 and 15 liters. That's around 4.4 liters per 100K. I seem to be using less fuel now. Just got back from the servo and at 300K I only put in 11.4 liters which is less than 4 liters per 100K (calculates to 3.83 L per 100K). A difference of around 0.5 liters per 100K. My previous fill was at Daylesford on the Choc mill ride last Saturday so most of it was hwy riding. I've noticed it on the last few fills. Is this normal? For those interested, I replaced it as I thought stock was too quiet and preferred to be heard a little better in traffic and not for better performance which I think is the same. But the economy side of it is a bonus.... And yes I fill it to the same level every time.