I'm looking to buy Blizzack LM-25's for my G35 coupe. Stock, it's 225/40VR19 for the front and 245/40VR19 for the back. Does anyone see any problems with getting 225/45VR19 for the rears?

 

Welcome

Check the diameter of the stock tire vs. the 225/45/19

I believe the 225/45 will be an inch shorter...this will probably give you problems with the VDC system.

You should consider going to a smaller size 17 or 18's. They are generally better in the snow because of the taller sidewall....

The choice is yours...
Check the wheels and tires forum.....many threads regarding this topic

Good luck

 

Using this tool http://www.miata.net/garage/tirecalc.html the diameter difference is .3". Think that'll affect the VDC system?

 

Since you own a quality coupe that's designed to drive it wouldn't be a good
idea to put 225's on the backside! What you should do is put 245's on the
front and no less than 275's on the rear......then you'll have a driver! There's
two things wrong with putting 225's on the backend.......too short (incorrect
height) causing excessive mileage to show on your car and poor handling!

 

I'm looking to get the closest setup I can to stock. I'm not looking to get high performance in the winter, I'm just looking not to get into an accident.

 

I guess you have the sport tuned suspension with
245/40R19 in the rear, I have the same and plan to
go for 225/40R19 snow tires both front & back, the
narrower tire will help get better traction in the snow
and in general better for all 4 tires to be of the same
width when driving in the snow.

I doubt you will be able to go for 45s since the tire
diameter will increase by 1 inch and that could give
problems with the suspension and vehicle stability
control, stick to 40R19 which is what this car was
designed for.