[PaleMelanesian]

High rpm acceleration is bad and consumes lots of gas. If you have a manual transmission you can do decent acceleration at not-high rpm, like 2000. If you press the pedal that same amount in an automatic it will push the rpm higher and consume more fuel. You can accelerate efficiently faster in a manual than an automatic.

High-throttle enrichment varies widely from car to car. Some you have to actually have the pedal to the floor and high rpm, like 4000+. Some cars, anything above 80% throttle will enrich the mix. So to be safe, I'd say keep the gas pedal at or below 3/4 if you don't know otherwise.