It's one of the most used and most important fixtures in a house. But when you're buying a toilet there's a lot more to consider than just style and shape, and a high price tag doesn’t necessarily guarantee performance.

Consumer Reports tested dozens of toilets to see if they wash away debris, clean the bowl after a flush and are water efficient.

Among the brands that were tested were the Delta Prelude and the Mansfield Alto. They both cost the same, at just under $200.

But the Prelude was a recommended model, while the Alto had the lowest score in their ratings. Why?

The Mansfield Alto didn’t get great marks for waste removal. In several tests the sponge debris stayed in the bowl. But the Delta Prelude did its main job very well, flushing away all the debris.

And how clean were the bowls afterwards?

Testers drew a water soluble marker line around the inside of the rim of the toilets, to see if one flush can wash it away.

The Mansfield bowl got fair marks, with marking left behind after each flush.

“A good performer has the power to rinse away most of the debris, most of the time,” said John Banta, with Consumer Reports.

The Delta Prelude model did an excellent job powerfully rinsing the ring away.

And when it comes to efficiency, the Delta uses less water than the Mansfield at just 1.28 gallons per flush, versus 1.6 gallons.

If you're wondering if your toilet is leaking and needs to be fixed or replaced, put a few drops of food colouring into your tank. If there is colour in the bowl within 15 minutes, then you've got a problem.