There ' s a lot that goes into how fast and powerful an engine is . Gear ratios , cylinder bore , rev limit , fuel flow and delivery , aspiration , etc . For instance I have a Ford Ranger with a 2 . 5 L Straight 4 , and a BMW 325 i with a 2 . 5 L Straight 6 . Same size engines , which are engineered to do completely different things . The Ford Ranger develops a lot of torque and has a lower red line with gearing designed to pull and then cruise while the BMW develops a lot more power up top , has a much higher redline , and has gearing thats shorter for better acceleration and power delivery throughout the power band . Edit I have a huge passion for cars and engines . If you have any questions , ask and Ill try to answer .