currently running 245 45 18 all around in my g35s. steering is very heavy right now. thinking of changing the front to 225/45 or 235/45. what do you recommend ?

I'm running 245s and it is very responsive. It's probably more due to the tire compound or tread. How much pressure are you running, try raising it a little.

That's normal if your new tires are summer tires and the old tires were all season. Just raise the PSI, you can do 1-2 psi higher in front since the car is slightly front-heavy.

I'm running Falken FK452's in 245-40-19 and I wouldn't call my steering heavy at all.
The car rocks on those tires.

I miss them.... gawd, winter sucks.

I will try 34 psi in front

I run 34-35psi all around on my 245s and steering is great.