# Is driving at 3000RPM the same for the car, whether you are in first or fifth gear?

So I was wondering, when taking the car on a straight in 5th gear at 3000RPM (~108km/h) or in first gear at 3000RPM (low speed), what are the differences experienced by the engine ?

Apart from airflow being better at high speed I guess, the engine still runs at the same pace. Is the fuel/air mixture different/very different ? Is it harder for the engine or are the transmission/driveshaft getting all the real hard work ?

Thanks!

• (My underlying question being, when I go to high speeds, am I damaging the engine more than when going to low speed, even at the same RPM) Commented Jul 3, 2018 at 2:49

What @Old-School Engineer says is correct. Wind resistance (aka drag) increases exponentially with speed. The (simplified) formula is `drag = (constant)*(velocity^2)`. So for example, going from 30kmh to 100kmh, the drag is 11 TIMES HIGHER. As a result, even though the engine is spinning at the same speed, it is consuming more fuel and air to maintain that RPM speed.