I used to do it all the time years ago in my Scirocco. In fact, I don't remember why, but I had disabled the switch that stops you from starting the car if the clutch wasn't in, so I would literally start the car in first gear, and never even touch the clutch to get up to speed. Not the smartest thing to do, and certainly not easier than using a clutch, but it was fun! (hey, I was a teenager, cut me some slack!)

 

They do it because of constant shifting, but mainly so they dont have to double clutch. In a regular car with a manual, you can pretty much step on the clutch, and go into gear. In a semi you cannot do that, you must be at the correct rpm, or you will not make your gear! That is what we call "dead sticking" in the trucking biz. We rely on our gears to slow down, along with our jake brake, which is that awesome noise you hear when a truck is slowing down! And, yes, as far as the car goes, it does save the clutch if done correctly.

 

The easiest practice up shifting is 3-4 I'd say, since it's centered in the box. Basically, accelerate in 3rd, lift off the gas and at the same time push the stick into neutral, then do not force it but rest it against the 4th gear gate. If you didn't take too long, when the rpm's match perfectly, the shifter will get "sucked in" and you will be off. Similar idea downshifting, touch the throttle, throw it into neutral, bump up a bit more than the rpm differential between the two gears and rest it against the gate. You'll definitely know if you did it wrong.

 

When the transmission output shaft and wheel speed are matched, it negates the job of the clutch. Since the output shaft is spinning at different speeds depending on what gear you're in, you can shift up and down through the gears by just rev-matching.

HOWEVER, get this wrong, and you'll just grind the gears. And if not done absolutely perfectly, it puts a lot of wear on the synchros, since you are in effect forcing the synchro to do part of the clutch's job.

Our customers used to do this, which is why we no longer offer 3-pedal manual transmission cars for rent anymore.

 

I do so from time to time to keep in practice, and quite often during the winter months in my rally car (race clutch from hell).

 

My friend dose it in his Cobra, he has a strong clutch and he's the one that showed me if you hit the right RPM, you could slip right in. I haven't tried it as I drive an Auto.

 

Or you you could just use your LEFT foot on a pedal and use your transmission and clutch as it was engineered. I enjoy a perfectly matched downshift.

That and I have always been too much of a pussy to risk blowing my tranny...