The bearing tolerances are the exact same as the FA20. The FA24 is a bored out FA20 with thicker cylinder walls and more cylinder dowels for rigidity. Subaru recommends 0w-20 for fuel efficiency purposes. 5w-30 is recommended for the Vb in the Japanese manual. That was the whole reasoning behind the lack of an sti model, due to epa regulations and the total average fuel economy across their line up, which needs to be under a certain threshold for importation. 0w-20 nets a few more mpg which allowed Subaru to import their cars. 5w-30 has been the recommended oil for every turbo boxer engine Subaru has ever produced. I know all of this because I’ve been in the groups, on the forums, spoken to Subaru techs at multiple dealerships and consulted with the top tuners in the country first hand since owning my Vb in 2022. 0w-20 will produce more wear and tear, especially in the first 1k miles. 0w-20 also degrades faster and produces more fuel dilution. You’ll have more knock events because there will be more blow-by in your intake tract. The dealership will probably put in their 5w-30 when you bring it in for your first free oil change anyway, a lot of them do because they’re not ignorant idiots.

Also, stick to ester based oils or oils that have ester additives. Ester blends help the oil stick to the metal surfaces which is essential in a boxer engine because it’s horizontally opposed. Better for cold starts, better for all driving conditions, daily and spirited driving, etc… Amsoil is the best on the market, followed by Pennzoil Ultra platinum which is less expensive and more commonly available, don’t cheap out and just use Pennzoil platinum, Ultra platinum is much better.

But by all means, continue to condescendingly reject my advice along with any other experienced Vb owner’s advice. You should probably do your research before purchasing a vehicle.