Ive just put 4.556 diffs in my hilux which was 3.583 prior . Basically Im 20% lower geared .
What has happened after about 50klm driving and a few on off starts the accelerator pedal has become virtually driving at the top of its stroke . Almost just feathering the accelerator to drive along at 60-80 . Seems the ecu has learned theres a much less engine load and the fueling has been altered. Engine now sounds like idle engine noise at road speed unless you put the engine under a bit more load then its very quiet but quickly becomes over the speed limit.
Anyone able to confirm if the ecu could have reduced fueling due to reduced engine load and less pedal press .
I guess the original fuel mapping is designed for the original vehicle parameters and reducing load by 20% is significant .