I just looked up the specs to the 324L. They're not horribly more heavy than Husqvarna's pricier 2-stroke units. The 324L is 11.2lbs, where the 2-stroke variants are ~9.5 to 11lbs.
I know when I had my little Troy-Bilt 4-stroke trimmer 10yrs ago, the oil sump was so tiny that a quart of oil would last years. It was like a 2-3oz oil sump. I personally would use any heavy-duty/fleet 15w40 in it, but a nice fancy bottle of boutique goodness certainly wouldn't break the bank given the micro-sump on these.
I know when I had my little Troy-Bilt 4-stroke trimmer 10yrs ago, the oil sump was so tiny that a quart of oil would last years. It was like a 2-3oz oil sump. I personally would use any heavy-duty/fleet 15w40 in it, but a nice fancy bottle of boutique goodness certainly wouldn't break the bank given the micro-sump on these.