err no, if you use the wrong latency the car will be spot on at WOT but way off at idle. the ecu calculates the amount of fuel required from its maps, then figures out how long the injector needs to spray fuel for, then adds the latency and pulses the injector for that long. so if you set the latency to 0 but the injector takes 1ms to open before it starts spraying fuel and the ecu thinks it needs 2ms of fuel at idle its only gonna pulse for 2ms, giving you 1ms of fuel, whereas if you set the latency properly it'll pulse for 3ms, giving the correct 2ms of fuel. at a constant voltage the latency never changes for a given injector, hence why it has more effect on idle than WOT