I switched to Amsoil in my FJR at 2800 miles. I now have 14600 miles. I change the oil every 6k miles and the filter every 3k miles.

I tried Mobil1 V-Twin 20w50 in my 99' Harley for 24k miles. It's a good oil but would start to disapear after 1500 miles. I switched to Amsoil's M/C 20w50 and would not have to add oil in 5000 miles. I road that bike until I sold it at 48k miles.

Don't know if this situation applies to other vehicles, but it's why I use it.

Roadhound