Hello,
To know the exact speed, you need to refer to the assembly generated.
The number of instruction will depend on where your values are stored.
S12XCPUVx will give a decomposition of instructions used.
With a char (byte), values can be stored in CPU registers A and B.
But int (word), values will not fit.
As the Guru said, an int will take more memory space.
If it is practical, I advise you to .use the smallest side.
After all, an addition between two "int" can give a "long".
Cheers,
Alban.