Locking nuts

[Eltel71]

Hi all..  I'm useless when comes to cars .. Just got a vvti with 18 inch alloys and not sure what pressure should be in them I've put at 30 psi at the mo.  

My other prob is there's no locking nuts. I went to Euro carparts for some and I was asked 19mm or 21mm.. 

Any advise or help appreciated..

Thanks.. 

[Heidfirst]

there should be a plate on the pillar of the driver's door with the tyre pressures for your car.

1 other thing to be aware of, if they are oem Toyota alloys they probably have a flat seat whereas third party alloys tend to have a conical seat.