Nice to see an oil viscosity by ambient temp chart. Been some time.
Toyota mandated 0w20 in my '13 Scion xd with 2Zr-FE. They even had a Service bulletin, Tech Tip S-TT-0073-13 reaffirming the mandate. To throw another bone in, they extended max OCI to 10k miles for models that mandated 0w20, only. For models that gave you a choice of 0w20 or 5W20 they mandated max OCI's of 5k mi. No matter the oil type. Like my '14 Scion xb. Also, if you must add 5W20, change it out soon.
Note the 4 reasons for this mandate. The third one is reduced waste stream, which some think is the reason behind their claim of "forever" ATF and coolant. Waste charges in some markets? But how does a 0W20 qualify as a 10k mi. oil and not 5W20? Assuming both are decent full syn's.
Excerpt from bulletin:
"Starting with the 2010 model year, Scion began a gradual transition to the use of synthetic Ow-20 viscosity engine oil.
There are multiple benefits of this oil, including: • Reduced friction and wear on engine surfaces • Improved fuel economy • Reduction in waste oil stream (in vehicles approved for 10,000 mile oil change intervals) • Reduced maintenance cost (in vehicles approved for 10,000 mile oil change intervals)
Due to the improved performance and durability of Ow-20 synthetic oil, Scion has extended the oil change intervals to 10,000 miles for vehicles that require this oil (except for FR-S). With this change, the following should be noted: • Only Scion vehicles in which Ow-20 oil is mandatory have been approved for extended oil change intervals • Vehicles in which Ow-20 is an option to 5w-20 (or 5w-30) will continue to require 5,000 mile change intervals, even if Ow-20 oil is used • In the case of vehicles with 10,000 mile oil change intervals, the 5,000 mile service interval has not been eliminated . The traditional 5,000 mile maintenance procedures (such as tire rotation) will continue to be required , and the fluid levels (including engine oil) will need to be checked and adjusted at this time • If the vehicle operation meets the standard criteria for "Special Operating Conditions" such as: driving off-road , on dirt roads, towing a trailer, making repeated short trips under 32° F, or extensive idling; the engine oil must be replaced at 5,000 mile intervals, regardless of oil used. Exception is FR-S, where the oil must be replaced every 3,750 miles, under "Special Operating Conditions"