In GTA IV, Roman will eventually offer Niko the service of his taxi company. When Niko opens the Phonebook on his mobile and presses Roman's name, there will be an option for a taxi ride, so that Niko can order a cab from Roman.
Niko can of course just hail a taxi from the side of the road.
These are the only taxi service options in the game.
To hail a cab in GTA IV on the PS3: (or Xbox 360)
Niko needs to be by the road where there are cabs to be seen. Choose a route on the map and mark it, unless there is already a marked destination for a mission. If you press L1 for PS3 or LB for Xbox, Niko should whistle for the cab. When the cab stops, take Niko to the door and hold down triangle for PS3 or Y for Xbox (make sure you hold it down, rather than just tap it, otherwise Niko will jack the cab instead). Niko will enter the cab. The driver will ask where he wants to go, and the destination should be seen on the dashboard. Just affirm the route and the journey can begin. You can skip the journey experience in cab if you don't want to see what is going on, or hurry the journey up. Details on the screen will give more information on this. Once Niko arrives and gets out, information on how much it cost will show on the bottom of the screen.
Alternatively, if Roman has previously offered Niko the use of his taxi company, just ring Roman on the phonebook and Niko will ask for a cab.
Hold L1 in front of a taxi
I believe this is Mission Number 51.
No... It is GTA 4!
It should do that automatically
you have to dial the number in on the cel phone yeah what that says
There isn't one In Gta IV
no
No.
endless.
You cannot
890-453-9655 is the cheat of nitro in GTA iv PS3.
You cannot, GTA SA has a much lower graphic system then GTA IV, plus the cars in GTA IV have more addons than GTA SA.