I was reading a thread in a car forum where someone wrote:
The lower the RPM, the less fuel you use, the less strain you put on everything..
Another person then replied, stating:
Not true. If your pulling high gears and making the engine work more to go how you want your using more gas. As well as putting more strain on the car. By wanting more from the car when it is out of its power your forcing the injectors to open more thus burning more gas. Please don't mislead anyone if your not sure. However, waiting until redline to shift isn't ideal either. Shifting at 3/4 or so of the torque curve is optimal for gas.
Who is correct? Is it more gas efficient to to shift at lower RPMs rather than high RPM? Would something like this vary great from car to car, model to model, or would it be a general rule for all standard engines?