Here's exactly what the Nighthawk forum member said -
"As it relates to lane splitting, loud pipes are a tremendous benefit because they open up the 'slot' thereby making it way easier to move along...While lane splitting is legal in California and we all have the option of doing it, it would really be better not to w/a stock pipe since it does not give the average car driver any warning that you are coming up alongside them. A bike w/ an aftermarket pipe (or any Harley for that matter) lets car drivers know that you are coming up from behind well before you are alongside. If you must split the lane w/ the stock pipe then keep the speed down-perhaps 10 mph faster than the cars are traveling and don't exceed 35 mph no matter what. Having ridden 10,000 or more miles/ year on the Southern California freeways for more than 20 years I highly recommend an aftermarket (loud) pipe if you are going to split lanes. Loud pipes do indeed save lives."






