I got 312,000 miles on the car since purchase in 2003 i get about 447 to tank of gas most high way, just can not believe the mile and it keeps going!

 

Thats great. Few questions:
When you say tank - how much gas do you fill every time (I do 15 - 16 gallons depending upon how much I drive after light comes on before refilling the tank, for kezorm only)?
How often do you do the oil change? What kind of oil, oil filter and air filter do you use?
What kind of gas?
What is you driving style? What is your average speed on this highway driving you mentioned?

 

Welcome to Club Lexus!

That's awesome! This is the first time I've heard of a 4ES with high mileage (they are still only a max of 10 years old). I've seen multiple 3ES with unbelievable amounts of miles on the ODO.

What have you replaced so far? Any repairs, or just maintainance.

 

How often do you do the oil change? What kind of oil, oil filter and air filter do you use?
What kind of gas?
What is you driving style? What is your average speed on this highway driving you mentioned?[/QUOTE]

oil - castrol GTX 5w-30 conventional
filter(s)- toyota oem
gas - chevron/techron - 87 octane
driving style - gentle
oil change - 5k interval
tire(s) - V rated - 32 psi all around - proper alignment
average speed - 65 mph with no load.

 

I noticed an interesting trend in my fuel economy. I cleaned my MAF sensor in mid June and recorded my highest MPG (27.1), soon after. It slowly went down to around 25-26, so I decided to clean it again - recorded 27.5, and I wasn't even trying that hard. This is with 85% highway driving.