Toyota recommends 0w-20. In other countries thicker oil has been recommended for older land cruisers. In the US we had a 5w-30 recommendation for the 1fz-fe when other parts of the world had thicker recommendations. The daily driver of the 200 series uses it for mixed city and highway drives, 60-70% city use. It accrues about 11k miles/year and is located in northern New York State. It is entirely stock. Would a 0w-30 or 0w-40 be a bad idea, specifically Castrol? I'm an oil newbie but higher hths in exchange for slightly less gas mileage would be an ok trade. Historically the land cruiser has been easy on oil with prior engines. I'm suspicious that Toyota has made this thin recommendation from government pressures on fuel economy as many of their new engines use 0w-20. Your input and expertise is appreciated.