[SEE YA]

Here's the deal - Looking at Nitto tires NT555 - Front, 255/45ZR18 with Torq-Thrust M rims (18x9, 34mm offset, rim size match tire)
Rear, 285/40ZR18 with Torq-Thrust M rims (18x10, 45mm offset, rim size match tire) Note: both tires are the same diameter.
One question is will there be any steering problems with the front size chosen ? Another, do the offsets look correct ? I don't want the offsets be off center of the steering.
Thanks for your help in advance.

See Ya

[EagleAutosports]

That setup should be fine. You shouldn't have any problems.

[HPMcGee]

your front tire diameter is about 1/8'' larger than your rear, which is nothing. I beleive the front rim is just about stock as far as Offset and backspacing. The back rim is an inch wider, yet the back spacing is increased by only 7/8'' which means your new rim will stick out 1/8'' farther than the old. The fronts are what matters most and since they're just about the same as stock... you're good. The rear tires are about an 1 1/2'' wider than stock so you will feel it going down a road with any kind of ruts or crowning. It will pull the car all over. On flat roads your golden. Its amazing what a difference an 1 1/2'' will make. Do the numbers for yourself. to convert milimeters to inches multiply by 25.4 that will give you the dimension in inches. Ex; 285mm x 25.4 = 11.22''