Sounds like you are asking opinions...I almost moved this thread out of the Lube section for that reason...it's for more technical type questions.
So, I'm going to give you a technical answer...shouldn't be hard to figure out
Concerning the Amsoil EaO filter, it's the best of the conventional filters out there. You're gonna pay for it though :runaway:
It is rated for 25,000 miles...personally I would not go that mileage, but would go 1 year if mileage was in the 15K range.
Personally, I'm not going to go over 8K for changing the oil without doing analysis.
Here's what Amsoil says about extended oil drain intervals:
Amsoil Signature series (SSO) 0W-30
• Normal Service(3) – Up to 35,000 miles or one year, whichever comes first.
• Severe Service(4) – Up to 17,500 miles or one year, whichever comes first.
• Replace AMSOIL Ea oil filter at the time of oil change up to 25,000 miles or one year, whichever comes first (other brands at standard OEM* intervals).
• In all non-gasoline fueled vehicle applications, extend the oil change interval according to oil analysis or follow the OEM* drain interval.
For Amsoil (ASL) 5W-30
• Normal Service(3) – Up to 25,000 miles or one year, whichever comes first.
• Severe Service(4) – Up to 15,000 miles or one year, whichever comes first.
• Replace AMSOIL Ea oil filter at the time of oil change up to 25,000 miles or one year, whichever comes first (other brands at standard OEM* intervals).
• In all non-gasoline fueled vehicle applications, extend the oil change interval according to oil analysis or follow the OEM* drain interval.
*OEM – Original Equipment Manufacturer
(1) Engines operating under modified conditions are excluded from extended drain recommendations. Examples include the use of performance computer chips; non-OEM approved exhaust, fuel or air induction systems; and the use of fuels other than those recommended for normal operation by the manufacturer.
(2) Mechanically sound engines are in good working condition and do not, for example, leak oil or consume excessive amounts, are not worn out, do not overheat, do not leak anti-freeze and have properly working emission control systems. AMSOIL recommends repairing malfunctioning engines prior to the installation of AMSOIL synthetic oils.
(3) Personal vehicles frequently traveling greater than 10 miles (16 km) at a time and not operating under severe service.
(4) Turbo/supercharged vehicles, commercial or fleet vehicles, extensive engine idling, first and subsequent use of AMSOIL in vehicles with over 100,000 miles, daily short trip driving less than 10 miles (16 km), frequent towing, plowing, hauling or dusty condition driving
Read the notes carefully