Is it OK while driving to switch from D to N then Press on the gas pedal then switch to D to increase speed ?

Only if you want to damage your transmission. When you put the transmission to N it is in Neutral or no gear. When you rev and shift to D it is violently shifted back into gear and that is hard on the components. If you want more speed just push the pedal to the floor. That will cause the trans to shift down a gear and increase it's ability to accelerate.

I wouldn't do that that's not good for your transmission your basically doing a neutral drop witch even already at a roll your causing damage to the internal parts. If you need more power or better acceleration then you need to find away to upgrade your transmission or fix your transmission. You can buy whats called a shift kit they make them for most cars out there you need to have a transmission shop install it and go with a better torque converter. A shift kit will firm up the shifting of the drive gears and control when they shift to get the most out of the transmission and driving experience a smaller and different stall converter will help you launch the car from a dead stop and maintain torque.

doing that some of these days you won,t be having that speed. in matter of fact you will be sitting because you will rip drive out of it plus who knows what else.. do what you want but i think i will keep my car in drive. you say you want to pick up more speed? well just push the accelerator 1/2 way or if you choose all the way to the floor. that way the transmission will shift into another gear and you will pick up more speed.

No! It does nothing but damage the transmission.

Push further down on the foot feed. It will shift to a lower gear and give you more speed.

No its not right, you wll tear the trans out of that thing. If you need more speed then find engine parts to help

Only if You like changing out Screwed up Transaxle(Transmission:

pressing on gas with the gear in d is better/you way results in trans failure prematurely

You're going to blow the planetaries right out of the side of the case that way.

If you want to waste fuel, lose momentum and speed and break your transmission - doh !

wow u are so going to strip out your gears if u do that often,if its for just a quick race here and there,then ok,but i wouldnt do that on a regular basis for nothing.