engnrng79

On my 2010 450h, the guide lines are an option accessed in the settings. You can turn them on or off. Have you checked your manual to see if you can set yours to on?

So, the difference in gasoline cost from 30 mpg to 24 mpg is about $2500 over 100,000 miles. Difficult to justify purchase of the hybrid vs 350 based on gas pricing alone. My personal motivation was based more on reduced emissions, longer life engine and brakes (neither has to work as hard), since we plan to own the vehicle a very long time, and I am an engineer and have had hybrids in our family for a dozen years. Yes, my mileage went down about 10% after putting new tires on, but next time I need new tires (later this year), I will get the current hi-tech low rolling resistance tires and expect the mileage to go back up. My biggest disappointment was the fuel gauge. I bought a 17 gal tank that shows empty with zero range at 14 gal used. I often go 50+ miles beyond empty and have never run out of gas. So, what are you going to sue for? $2500 "damages" + $250,000 legal fees?

What does the dealer say? All hybrid components are under warranty in California until 150,000 miles. Any codes? Does the displayed mileage match your calculated mileage at each fill up?

2010 450h, in 2013 mileage averaged 29/30 mpg combined city/highway (mostly highway at 65 to 70 mph). Put on new tires last year, then mileage dropped to 27 mpg (factory air pressure settings). I increased air pressure to just under sidewall maximum and mileage improved about 0.5 mpg. During summer, mileage is as much as 2 mpg higher than during winter. 75 to 80 mph on highway drops mileage 2 mpg. I leave the car in ECO mode setting which reduces gas wasted during hard acceleration. Lots of factors involved. On my best tank, I have not seen an average over 30 mpg, on my worst tank I have not seen below 26. In my opinion, 24 mpg sounds low, even if it were the result of high speed/high acceleration driving. Ever had any error codes? EPA test ratings of hybrids always yield high mpg numbers and manufacturers are required to put those numbers out to the public, even if the engineers recommend otherwise. Later, EPA denies all responsibility and manufacturer ends up eating $millions, so there is precedent for your suit (Ford CMax and Fusion) . Typical results are that a hybrid version gets 25% better mileage than the non-hybrid version of the same car. What does the RX350 typically get?

"Most of your advice is good but I have to call out the "pump up the pressure" myth! Increasing tire pressure, even significantly is proven to have no effect on fuel economy: http://www.popularmechanics.com/cars/news/4199963 " This article actually proves that higher tire inflation has a significant positive affect on mpg. The authors ignored the simple physics involved going uphill vs going downhill. If they had done the test in reverse, they would have claimed an effect much higher than reality. Why is it that people who don't know physics or math get to write these articles and why is it that the editor of Popular Mechanics prints them? OK, I know. It is called "Popular Mechanics". It is not called "Actual Real World Mechanics". So, they only print what might be "popular" and therefore sell more copies. I used to have an expectation that this magazine had some integrity. Not any more. Also, the "recommended tire pressure" on the tag on your door is what the manufacturer figures is the best compromise between ride comfort, handling safety, tire life, and mileage. The maximum rated safe tire pressure can be found on the side wall of the tire.

Last year, our dealer replaced our tires, mileage dropped from 30 to 27 mpg. As the tires wear, our mileage is slowly climbing back up. I also increased tire pressure to 40 for another small improvement. This may not have anything to do with your vehicle, though. Did you replace your tires at 50k miles? Was there a software "upgrade"?

The oxygen sensor is one of several critical components in an emission control system. Feedback from the sensor can actually affect air flow, fuel flow, temperature control, engine load control, etc. Therefore, faulty readings or a failed sensor can cause an increase in fuel consumption, loss of power, dirty injectors, valve damage, piston damage, bearing failures, destruction of the catalytic converter. With modern electronically controlled engines, it is usually a good idea to keep all systems working within specifications. In California, with its strict emission controls and bi-annual mandatory checks (except on hybrids), cars are kept working in good condition for longer, and smog days in Los Angeles have been reduced from over 150/year (most lasting all day) to under 100 per year (with many alerts lasting for 1 hour or less) even though the reporting standards have become far more strict. Most of the ozone and particles are now coming from non-automotive sources. How is Denver doing?

Unlikely a money grab, IMO. After all, the vehicle recorded the code, unless you believe the vehicle conspired with the dealer. Oxygen sensors are electronic devices in a very hot and high vibration environment, are subject to momentary failures (likely in your case) and do degrade over time. A momentary glitch can also be caused by water in the fuel or just a bad batch of fuel (high ethanol content). Typically they last over 100k miles. If you have zero trust and faith in your dealer, you can get your own ODB reader the next time a "check engine" light comes on and check the code for yourself, even clear most codes yourself to see if they recur. The dealer could have told you if it was a recorded fault or an active fault (since it cleared, it was not active at the time), but since most people do not know the difference, they probably don't bother.

I see you are in Colorado. Were you at high altitude when the light came on? I would wait until it comes on again. Does Colorado have regular emissions checks when you update your registration?

Who told you that? Toyota testing shows 300,000 miles on the Prius battery, then can be rebuilt for about $1000. The small 12V battery in almost any car should be replaced at 4 to 5 years to prevent being stranded. Traction battery should last a long time. Lexus dealer can check battery condition.