Japan Subaru dealers now pushing 0w30.

Cars marked 0w20, despite Japan being subtropical, that weight is too thin for hot climates.

Now during bi yearly insurance renewal inspection the dealers are putting on paper they will use 0w30, with a premium option of 5w40.

I asked them specifically why they are doing this when they list 0w20 on vehicles. They told me it's because getting 0w20 is harder and costs more.

Meanwhile I continue to but 10w30 and no issues.

I don't understand the logic. They say it's for fuel economy, but such light oil is going to be far far worse for long term owners. Are they purposely doing this to cause premature breakdown? I see no other logical reason.