Jeez, some ppl talk a load of ****y poo!
'Load' has nothing to do with the stickiness or otherwise of your tyres, Killer.
The 'load' seen by the ECU is basically being measured by the AFM. The ECU has a little table, with 'load' along one side and 'rpm' - which it gets from the CAS - along the other. At each point in the table, there is an 'open the injector' time. So, the ECU gets the load and rpm, and 'looks up' the injector time.
If you change the fuel pressure - by changing the pressure regulator - , then you can change the amount of fuel injected during the duty cycle (injector open time). I've read that its more effective to increase the fuel pressure than to fit larger injectors if you need more fuel for a given duty cycle. Not only do you get more fuel, but it gives a better spray pattern as well.