I think it would stick out too much to add the tile over the granite. I dont think it is a no no, you do what you want, but I personally dont like that look with tile over a granite backsplash but I have seen it done.

I think you're asking if you can add the tile backsplash beginning at the top of the granite backsplash. I am toying with the idea now, but struggle with color and the idea of giving up the flexibility of a painted backsplash area.

Your title is misleading - it sounds like you want to tile overtop of your granite backsplash...But, I think what you mean is to put tile on the wall above the 4" granite strip, or should you remove the strip first.

In my kitchen, I have my tile backsplash come all the way down to the granite counter - I did not have a 4" granite backsplash installed. I personally like the look of the backsplash coming down directly to the counter, but in your case don't know if I'd go to the trouble of removing the granite.

I think it would depend on your granite and the tile you've chosen.

I've linked below to the Finished Kitchen's Blog backsplash slideshow. You'll see all kinds of backsplashes with granite - maybe that will help visualize what you'll have if you leave the granite 4" strip or take it out.

Here is a link that might be useful: Finished Kitchens Backsplash slideshow

I wouldn't tile over the granite but if you're going to tile above the granite, treat it as trim for the backsplash. I would put some tile molding/trim at the top of the granite, then start the tile work of your backsplash.

I tend to think that tile above an existing granite backsplash looks a bit like an afterthought, not a planned design element. If it can be easily removed I would take it out then tile all the way down to the counter. If it's not practical to remove the existing granite, try to come up with a design that makes that part look like a planned part of the backsplash design. Maybe incorporating a tile liner that is thicker than the field tile or some other border.

I'm very interested in this thread, as I am facing the same problem with a house we purchased. I prefer tile down to the countertop, but the previous owner did a granite backsplash & I just don't know what kind of a job it would be for the dh to remove it then tile. I like annz suggestion if removing it is too difficult!

I have a black granite countertop with a 4 inch strip on the wall behind it. We tiled above the strip with black, gray and while glass tile squares and it looks fabulous!

In the subdivision we just moved to everyone has a granite backsplash and most people have tiled above it and it looks very nice. I am trying to decide which way to go and have looked at a lot of kitchen pics. I see it both ways. I talked to the granite guy who installed the kitchen granite and he said some people glue on the backsplash and removing it does damage to the wallboard. we just had one removed in our bathroom to replace the granite sink top and backsplash and it tore up the wall pretty badly. He said that he doesnt glue though so taking my kitchen backsplash off would be easy he said...just havee the tile guy do it he said. So all that to say maybe you could talk to the people who did your granite and find out how they applied the backsplash.
then you will know how much trouble it would be.