Yikes....got my tire delivery today and they are huge!!!!

Nitto Terra Grapplers 285 60 18

Will they really fit properly on my stock 2001 18" rims? ?
They look sooooo huge next to the 245's on there now!

With these mounted what will my speedo error be....I am guessing when I'm doing about 60mph the speedo will show 55mph?

Also will I be driving more miles than my odometer will show?

I will be mounting these next week if all goes well.

Thank you to all who has helped me with your posts on this subject !

Dave