How much oil does a 2005 chevy trailblazer take?

The 4.2 liter 6 cylinder engine under the hood of the 2005 Chevrolet TrailBlazer might be bad on gas, but it's certainly good on oil. You'll need just a hair over five quarts of SAE 5W-30 full synthetic oil, though in a pinch, this can be replaced with SAE 5W-40 conventional oil for short periods. However, the latter isn't recommended, for some very important reasons. Oil weight is essentially the oil's viscosity at varying temperatures. The "5" indicates viscosity at startup, and the "30" of "40" indicates viscosity at operating temperature. Lower numbers are better, so using the SAE 5W-40 over long periods can prematurely wear Your engine, resulting in reduced efficiency -- which can in turn lead to reduced engine life. Even though it's a few dollars more, don't hesitate to go with the best oil Chevrolet recommends; You'll thank Yourself in the long run.