As you know, gas prices are high as hell, so by trying to save gas I normally shift from 3rd to six gears when it reach 35-40mph. It doesn't seem to catch that well, the car tend to heistated until it reach a certain speed 50+ before it is normal again. Will it damage my tranmision or clutch? This is my first stick shift car by the way.

 

Generally its much better to go thru all gears as you go up.

Anything above 2,500 RPM should be sufficient for just "cruising" - You don't want to lug the engine (meaning its working too hard to maintain its current engine speed)... you'll also eat up just as much gas at too low of an RPM as you would being too high... Our car loves revs, and anythin between 3,000 - 4,500 RPM will get you very reasonable gas mileage.

 

you don't have to go thru all the gears, it's perfectly fine to skip. that's what non-sequential gearboxes are for If i were trying to save gas, i'd go to 5th tops for 35-40mph.

 

~2500 is the sweet spot if you dont want to lug the motor and get good gas mileage. whenever im driving in the city, i select a gear that keeps the rpm near 2500 rpm.