My truck has 18'' rims and I want to down size to 17'' rims will this work or not? It's a 2011 Toyota Tundra.

in short yes. but there are several things to keep in mind with this kind of change. changing wheel size will make your speedometer read incorrectly a way around this is to buy tires with a larger profile so that the rolling circumference stays the same but in doing this you may find that you need a hard to get tire making them more expensive. also you will need to make sure the new wheels match the studs even slightly off and you could break the studs (a good dealer should be able to advise you on this) also changing the wheels/tires can affect the handling of you car as well. hope this helps.