I just installed 20mm H&R spacers on my 2011 G37s sedan and I think they stick out too much. This is a 6MT car which comes with the Sport suspension. Everything in the suspension is stock and these are stock wheels. I went for a drive and no rubbing but no one was in the back seat.

The fronts are OK but the backs stick out too much. Do I just need to get more negative camber or should I switch to 15mm?

 

From your pictures it does not appear that you car is lowered so the tires appear to be out too far. I had the exact same H&R 20mm spacers with the stock tires and wheels on my 2010 6MT and they were perfect. In my case I was lowered on H&R springs (which pretty much slams the G). The only rubbing I had was when the steering was fully locked such as doing a U-turn. Don't know if you plan on lowering it but it will look much better when you do.

 

Yes, it is the stock Sport suspension. If it tucks into the wheel well better with lower springs, then it must do that because of the increase in negative camber in the rear.

Yardie, do you have a sedan or coupe?

 

I figured it out so I thought I would share.

When you lower a G37, the car will automatically get more negative camber which is more dramatic than say a McPherson Strut suspension. To compensate for the increase of negative camber, you can increase the wheel offset.

So if you lower you car, you can add spacers to get camber back. If you add spacers without changing the springs, then you are basically adding too much camber which is what I did.

Spacers seem like a hack to me now. Lowering springs changes the suspension geometry and adding spacers attempts to change that back to near stock. Probably the better way to lower the car is to replace the springs and a new knuckle rather than adding a spacer. But a new knuckle would be too expensive.

 

I have a sedan. I added the spacers after I lowered because when I lowered, the wheels were really tucked inside the fender and it looked really funny. Once I added the spacers it looked great because it brought the wheels right back to the edge of the fenders. I did have to add a toe/camber kit to get all specs back into line so I wouldn't eat thru tires.