In February 2006 I purchased 285 75 R16 tires to go on the Discovery.
A friend of mine told me that he was familiar with a Range Rover Classic that has 285 75 R16 tires and it does great on the trail. I thought I would get a set myself. When I ordered the tires, Discount said they would not install them on my 7 inch wide rims. They had to be at least 8 inches wide. I called Safari Gard to inquire about buying rims they sell that are wider. I was warned by Greg there (via his secretary) that tires of this size are way big for a Discovery and a lot of fender trimming would be required. His secretary told me he would call me back to discuss the details personally. He never did call me back but he is, as we all know, notorious for poor customer service. Undeterred, I bought the tires and found a shop that would install them on my 7 inch rims. Next I had to figure out how to make them fit. I don't think the trail is the right place to find out where your tires rub.
I took my truck to 4 Wheeler's Supply and drove it as far as I could up their ramp. I marked the places where the tires rubbed with Masking Tape.
After I got home, I arranged the masking tape until I got smooth curve. I then marked the curve with a silver Sharpie and removed the masking tape.
I then cut the car using a disk grinder.
Before I started any cutting, I used a caliper to measure the distances I would be cutting and marked the opposite fender. Again I used the masking tape to get a smooth curve following the dots, marked the line with a sharpie, removed the tape, and cut again.
Comparison before and after the trimming.
A trip back to the ramp shows that the rear still rubs here and against the car inside the wheel well during extreme articulation. I haven't decided whether to get shorter shocks, eliminate the articulation cones, or ignore it.