Poor Gas Mileage
 

I have a 2007 ES350 with 89K miles on it. I remember the gas mileage was somewhere around 28 MPG when I bought the car in 2006, but now it is running at 15 MPG. The ES performs like a rocket car (incredible power, no hesitation). There are no warning lights...just poor gas mileage. The car has been serviced by Lexus every 5K miles throughout its life.

Before I pour money into the engine, I wanted to post my experience here for recommendations.

Thanks

I think we need to know more about how you are driving the car, lots of sudden acceleration? In-town stop/start driving? Do you have a load of stuff in your car that you're carting around which you should really store at home?

I get 19mpg urban and maybe 30mpg highway on a good day. Have you tried putting in some valve and injector cleaner into your next fillup to see if that might help?

By service do you mean just an oil change or a full inspection as well? A lot of dealers are now offering the "economy" option of just doing the oil change and not really inspecting the car for any potential issues.

Good morning, I have a 2008 ES350 that I bought used at 75k miles that has 80k miles now. I did two oil changes quickly with (who knows the truth about the previous owner's maintenance) as well as two tanks of premium gas with Techron fuel injector cleaner.

Also, I made sure to change the PCV valve as well.

I am obsessive about clocking my MPG; I have always driven carefully and slowly, and I get about 17.5 around town, and routinely get 28 on the highway (using cruise control right at 70 MPH). This fits right into the manufacturer claim of: "Up to 19 city / 27 highway".

Drop that lead foot, man! ha

Regards,
Earl

Have the oxygen sensors been replaced yet? They are responsible for telling the computer the correct air/fuel mixture. Even if they do not show up as being faulty by the car's computer diagnostic system, old o2 sensors can feed the wrong signal to the computer due to carbon build up. The car will still run like normal too due to 'laggy' o2 sensors.

That sounds like average to slightly worse than average mileage for a 15 year old vehicle with almost 90,000 miles.
As others said, run some Techron fuel system cleaner through the gas, change your PCV valve, change your engine air filter.
In addition
Check your tire pressure.
Make sure you do not have dragging brakes meaning are the brake caliper slide pins properly lubricated? They are often overlooked.
Has the transmission fluid ever been changed?

You would have to drive it another 10 years to get back the difference in gas mileage if you spent more than a few hundred dollars trying to get it to run better.