When you make changes to your bathroom the toilet is an important part of the equation. What is there to consider? The shape and style, right? And whether it will fit the right distance from the wall.

But there is so much more. Not all toilets perform the same.

Consumer Reports is testing toilets to see if they effectively wash away debris, whether the bowl is left clean after a flush and how water-efficient they are.

What makes one toilet better than another? To illustrate, Consumer Reports selected two toilets that cost the same price-- $150.

One is a recommended model and the other has the lowest score in their ratings.

The Mansfield Alto received “fair” marks for waste removal. In several tests, the sponge debris stayed in the bowl.

But the Delta Prelude does its main job very well.

And how clean is the bowl surface afterwards? One Consumer Reports test is to draw a water-soluble marker ring around the inside of the rim, to see if one flush can wash it away.

The Mansfield bowl was only fair, with markings left behind after each flush.

A good performer has the power to rinse away most of the debris, most of the time. The Consumer Reports-recommended Delta model did an excellent job powerfully rinsing the ring away.

And when you shop, it's important to check out the efficiency rating. The Delta uses less water than the Mansfield at just 1.28 gallons per flush compared to 1.6.

If you have a toilet from before 1990, you can save 19 gallons per person, per day by switching to one with the EPA’s WaterSense sticker on it.

And to find out if yours is leaking and needs to be fixed or replaced, put a few drops of food coloring into the tank. In 15 minutes if there is color in the bowl, you’ve got a leak.