First of all MUBARIKBAAD on your new car, wishing you safe drive.
I'm running a 2005 CiTY on CNG, it works OKAY, not so good in pick, but I've done 180 on CNG. There's no modification in my car but the quad tip plugs & 14" rims. It gives me 130-150 inner city milage in a 60kg cyl.
I've installed the LENDIRANZO kit with ZETRONIC emulater & advancer, with a 60kg cly. in RS45000.
In my opinion it better to use ZIC A+ engine oil.