ok i just bought a used 07 g35x with 50 k miles. car is beautiful. here are my issues:
1) when car shifts from 2nd to 3rd there is this kind of quick shift or out of place shift when driving normal, rpms will quickly drop 200 then go right back up
2) car doesnt feel smooth at all with its shifts, very jerky especiall down hill
3) steering feels incredibly heavy
4) under very light acceleration around 1500 rpms car has a shake in motor feels like misfire

i bought car into local infiniti dealer to address all these issues and tech found no prob with tranny,they did find rpm fluctation and reprogrammed ecu but apparently this didnt fix prob. this isnt my first g. i had an 05 and i have to say that i had zero issues with that car upto 96k miles. a friend told that having two different sets of tires on all wheel drive car( same size) might create irregular shifting and feel to car. again this is how i bought car. i did a carfax on car before purchase. any thoughts on whats causing these problems??

 

ok just realized i wrote this in wrong forum. sorry