How come we can’t just add X amount of gears to a transmission and have one of the most efficient cars ever?
In: 95
Every additional set of gears is another source of drag. The friction of the gears will lower the efficiency of the transmission.
Also, if you only have x amount of space for the transmission in the car, more gears means each gear ratio will be thinner. Thinner gears means weaker gears. Say you have 1e inches in the transmission. A 3 speed can have gears 4 inches wide. A 4 speed, 3 inch wide gears. A 6 speed, 2 inch wide gears. An 8 speed, 1.5 inches wide. ALL that engine power has to go through that little surface.
Then there’s cost. The more gears, the more parts and the more engineering, the more wear, the more stuff can go wrong, and the more time to put it together. It just gets more expensive.
Last, it’s benefit. Realistically, your car is not going over 80 for very long. With a 5 speed, you’re still only dropping about 500 rpm between shifts, and cruising at 65 at around 2500 to 3000 rpm. Extra gears are ot going to get you that much. Even in sports cars, 6th gear is a cruising gear, not a top speed gear. It’s put in so the car is just above idle at highway speeds, so the car gets better fuel efficiency numbers.
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