Hey Scotty my mom just bought a 2008 Lexus RX400h AWD with 180k miles from private seller. I’ve done OE spark plugs NGK’s, pcv, transmission drain & fill, differential drain & fill. I’ve noticed she’s been getting 20 mpg’s in the city & on the highway. I want to get better mpg’s because Toyota’s owner manual says I should be getting 27 mpg city & 24 highway. This is all driving in Los Angeles so no hills. Do you know what I can do to get better mpg’s?
It's a 17-year-old hybrid. Was an analysis of the battery condition done before purchase? (It should have been done.) If the hybrid battery is weak, which is probable if original, the gasoline engine has to work harder and gas mileage will suffer. The mileage figures quoted in the owner's manual assume a new battery. Note that Scotty advises against buying older hybrids due to potentially expensive issues with the battery and other components as they wear.
Other than that, you can check the simple stuff like air filter and tire pressure. Also see our FAQ for fuel economy tips.
