I have a 1997 Corolla with a 1.6L and uses about 1 qt every 2k miles on 5w30. I'd stick with the original as specified.
I would say choosing a good oil filter for consistent oil flow and filtering is more important than the oil viscosity. At start up, the viscosities are too similar for then...
My parents have a 2005 Avalon and use the 5w30 synthetic since new and at 260k miles with hardly any oil loss.
Fix the oil leak, because a higher viscosity oil will not stop or slow the leak and might make starting the car a bid harder to do.
Always fix the mechanical problem, because a...
I use Amsoil 10w30 with the Wix filter with my 2.5l for years. Lost only 1/2 quart per 6k miles at 15k oci and no start up tick. Also the engine was rebuilt about 30k ago.
These engines will use any good brand of oil with a good filter.
My parent's 05 Avalon at 240k+ miles hardly uses any oil still.
The cartridge oil filter system on this car is still better than any Ecotec car. Afraid of busting those plastic caps when changing it.