I'm hoping some of the wheel gurus can help me here. I picked up a single wheel and am waiting to see if the company is going to put up the other since they would not just sell my both at once (Ebay pita) but it was too good of a deal to pass up. They told me they have a second wheel with the same specs but just in case they were full of it. This will be for my rears.
The wheel is a 19x10 +42mm, the wheel I found from a different vendor is a 19x10 +40mm. I'm trying to see how big of a difference the 2mm will make, I know it wont effect the rotation since everything else is the same but I'd like some opinions. Hopefully they have the one they say they do but just in case I figured I'd ask.

 

2 mm should not make much difference. My LS400 was bought new from lexus with original rims with 40 mm offset.
According to the documentation that was what was recommended for it. However those rims where 17x8 +40 mm
And 235 wide mm tires was the original