I've just gone through the same thing with tires. Local dealers just look at their listing for the D1 and tell you that 235 70 R16 is the right tire for you. They aren't a real common size. I got 4 new 245 70 R16s instead. The diameter is only very slightly larger, so your speedo will read a tiny bit low, but this is a very common size and will fit straight on without any chance of scrubbing on the guards. I think I read here that people have fitted up to 265 70 R16s without having to cut the guards.
I got Bridgestone Dueler A/T tires for $240 each, fitted and my old tires disposed of.

