Very Poor Gas Mileage

[mdw00]

Ok this is my first topic on here so dont know if I filled in the for correctly at the top anyways here goes.

2000 Lexus RX 300

1 before me

8k, and Tampa FL

Purchased June of 08, past 2 months

Have not had it checked out yet

No Mods

I'm 26

Ok, I have searched the for the average gas mileage people have been getting city and hwy. City I get about 180mi/tank city and hwy miles...just hwy I get about 200mi/tank driving about 80-85 mi/hr in good weather. I use mid grade gas and have used premium gas. My car passed the emissions test in June of 08. Car drive smooth and low and high speeds. Tires are properly inflated, just had tires rotated, serviced 2 weeks at a Tires Plus. What could be the reason Im getting such poor gas mileage just highway driving.

[mccldwll]

Ok this is my first topic on here so dont know if I filled in the for correctly at the top anyways here goes.

2000 Lexus RX 300

1 before me

8k, and Tampa FL

Purchased June of 08, past 2 months

Have not had it checked out yet

No Mods

I'm 26

Ok, I have searched the for the average gas mileage people have been getting city and hwy. City I get about 180mi/tank city and hwy miles...just hwy I get about 200mi/tank driving about 80-85 mi/hr in good weather. I use mid grade gas and have used premium gas. My car passed the emissions test in June of 08. Car drive smooth and low and high speeds. Tires are properly inflated, just had tires rotated, serviced 2 weeks at a Tires Plus. What could be the reason Im getting such poor gas mileage just highway driving.

You're not driving fast enough. At about 95 mph, the aerodynamics improve tremendously. You'll get 28-30. Not.

[smooth1]

Well, there could be a couple of issues going on here. The RX's ECU over time learns your driving habits, and how you use the accellerator and braking. So as the time passes it adjusts and changes some of the settings to accomodate your driving style. You have only had it for 2 months, and I don't know how many miles you have put on it since you got it, but I'm sure your not driving it the way the owner did before you. Those differences in driving habits could be partly to blame. So you can give it more time for the computer to learn you, or you can do an ECU reset and start the learning process all over again just based on your driving habits alone. To do this, you'll just need to remove the negative battery cable for about 20 minutes. Your going to lose your radio presets and seat settings and so on, but you should see better gas mileage right away. Another thing to do is maybe inspect and clean the MAF, and while your there, just make sure it has a good air filter in there, and all the air ducting is connected and not clogged or anything.

And when you say the tires are properly inflated, properly inflated to what> and what tires are on the car?