Hi Scotty,
I recently bought a 2001 Toyota Highlander V6 Limited (4WD) for my mother. 130k miles. I bought it from the original owners, and they had a lot of paperwork (and we live in CA which is a bi-annual testing state) so I'm confident the mileage is real.
The car gets lousy gas mileage, something on the order of 13 city and 15 highway, which makes my mother nuts (she's threatening to go back to the 1994 corolla 5 speed she's owned since new).
As far as I can tell, it's in excellent mechanical condition. No engine codes, idles and drives nice, hardly burns oil (maybe 0.25qt between intervals). Transmission shifts smoothly and into all gears. Power seems normal. Good tires, drives straight.
When I bought it I changed the oil and filter, spark plugs, ignition coils, coolant, and transmission fluid.
Since then, in trying to fix the MPG, I cleaned the MAF, then changed the MAF, and replaced the thermostat. All OEM parts. No change.
I'm a locksmith, so I have a fancy Autel scan tool, but I've never used it for mechanical diagnosis beyond basic code-pulling.
What should I do next?
please see the fuel economy topic in our FAQ
You could record some data and look at basics like fuel trims. (In-depth analysis of data really needs an expert but fuel trims can often help with a problem.)
