If you use 10w30 cheapo stuff in your engine it will behave very nicely, 5w50 is quite heavy lube for this engine, the oil pump bypass will remain open most of the time with that heavy oil.
For gearbox oil, when these cars were launched sae90 GL4 was a light weight gear oil. You might find it silly but It took Toyota another 20 years to retire the sae90 gear oil spec and go to 75w110 spec now.
Suzuki caught on earlier.
But ive seen really idiotic stuff in Pakistan, tiny bolan differential filled with cheap sae140 gear oil. This oil was like a semi solid at low temperature. It literally was pushed aside in the diff housing as the differential spun and the gearset was running dry.