Hi guys I have a 2008 G37S coupe. I’m going to be on bags and have molded in wide body fenders in the rear and currently have carbon fiber fenders in the front. I just got ew wheels do you guys know what a good tire size is. I’m going to be running 20x10.5 in front and 20x11.5 rear

 

Well, you're stuck with the <3% change allowed by the ECU unless you don't mind covering the warning light or snipping its wire.

So, just use the tire calculator in the top banner to work it out. Now, if you want me to make a recommendation, I will charge you a fee to do that simple job. You could, in addition, use the search feature in Tech/Wheels & Tires forum, or browse the Media Share forum for 20" wheels...

 

275 front 305 rear biggest I've run wo rubbing