I have 2 different jugs of engine oil in the garage. One is synthetic and the other one is tri-synthetic (according to the jugs) the synthetic says its aproved for a whole bunch of abbreviated things with numbers, like SAF-13 or something (i just made that up) and the synthetic one says it's approved for japanese valvetrain wear requirements or something. The tri-synthetic doesn't say anything about japanese vehicles. Does any of this mean anything? Or as long as I have appropriate oil for my climate I should be fine? This is 10W-30 oil BTW...This is going both into the jimmy with a 350 and also the toyota with the 22re engine... The reason I just don't use the synthetic one which is approved for a whole bunch of things is I only have maybe .5 litres left. The Tri-syntetic I have at least 5 litres... help?