Yes you got better fuel economy, but like Chris said, over inflated will mean centre wear. Everything has an optimum range.
For normal (not really low profile) tyres use the 4psi rule:
Drive half an hour in 110 zone and tyre pressures should go up by 4psi. Anything more, they were too low to start with and the tryre deformation and friction increased heat = pressure up.
Any less than 4psi increase they were too high to start with.
Then, to get pressures right relevant to how
you drive, and assuming alignment is correct: also look at wear at the time of getting new tyres. If you always run a certain pressure but outside shoulders are worn off, you need more pressure. Move evident on front tyres of young chicks cars that get thrown around corners with 20psi and strangely enough they understeer badly and wear outside shoulders.
If you have centre wear, you are over inflated. Or need to go around corners faster
Anyway Avalon being fwd, go 38 front 32 rear. Enjoy the handling improvement (within the limits of a sloppy thing designed to understeer).