If you really want to go back to a 15, you will need back spacing around 2 5/8 inch on what ever rim you chose or a space(1.5 in) that will get the rim away from the caliper. that will give you the clearence to run the 15 inch rim aournd the calipers. Personally my next rim is going to be a 17inch to get better tire choices. It has been suggested you could girnd the caliper to make them fit, but I think that is not safe. later robbie
I put my 15" wheels with 35's on the FZJ from the FJ40 just to see, They rubbed on the front clipers, They were aluminum rims, I would imagine steel wouldnt be quite as thick on the inside.
I dont know why you would want to get 15's, But its your vehicle, The reason being 16" have a better load rate...IIRC
315s are about as big as you can go in a 16" rim that is why I'm sure he is looking. Steering becomes and issue with the less backspaced wheels as when you turn your tire takes out your flare and fender. The clearance problem I found to go to the 2 5/8" as powderpig suggested is in the rear and then the steering problem comes in the front. So it is sort of tough unless you are ready to trim.
Thank you for your help everyone. i am going to try the backspacing to try and put them on. The main reason that i am trying to go to 15 inch wheels is because of the lack of sizes available for 16 inch wheel. i know that they are out there but i am stationed in okinawa japan and there are plenty 15 inch tires around but no 16's. so thats again. okay if all fails how much can i grind off the caliper.