My mileage on the LCD is way off. I calculated the old fashion way and got 22.4 running 60-65 on highway.

 

Try resetting the average MPG, by holding down the "info" button.

Mine is extremely accurate, usually .2 either below or over the actual average mpg I'm getting. Pretty good if you ask me. My ES on the other hand is terrible, it's always 1.5 mpg under what I'm really getting.

 

After having my oil control valve done the day of my post.. at the dealership in Springfield, MO - I first got 21-26hwy.... then it dropped when I went to local driving in very hilly Branson. Now I average 15.6 with mixed CTY/HWY. Very little HWY will drop it below 15.... and that's with all clean everything after a $1200 visit to the dealer.

BTY - I made them check and clean the little red node on a tiny metal thing in the emissions (i forget)... they were not going to do that until I asked. They did not charge me and used my CRC to do it. (i brought it)

 

Along with reset info button, try pulling the EFI and ECU fuses. This made mine a lot more accurate.

 

Ok...so I just picked up my 2001 with 103k and reset the mpg info for the ride home. Over the next 5 days I filled up on 93 octane and inflated all tires to proper pressure. It was reading an avg of 17.5. Very discouraging since I was driving like an 83 year old grandmother.

Today I cleaned up MAF sensor, changed oil and trans fluid. Added Auto RX as I have an oil drip. I also disconnected the battery for 10 min. I did not touch the PCV valve or the other ICMV? valve.

Long story short, my mpg reading went up about by about 8! Hard to believe it really improved this much so I'm thinking this is either wrong OR the previous reading was wrong.

One addition note - before I reset the mpg during my initial ride home, it was reading an unmoving 22.4 (like the original owner hadn't reset the mpg in quite a while).

 

I bet cleaning the MAF and resetting the battery did the trick!

I've seen massive improvement after cleaning the MAF sensor. I can honestly manage close to 20- 21 mpg in the city if I try. I keep it below 2.5k rpm and time out the lights to ensure I don't hit a red, and If I do I'll coast up to it in and effort to keep the block of an SUV easier to get going again. I generally don't drive like this though, since one NJ people will drive you off the road if you drive this slow, number two, I hate driving slow. I do it occasionally as a game, cause I'll admit it's kinda fun seeing how high you can get your mpg. But, it's just as fun trying to see how low you can get your mpg as well!

 

I play that game too. NJ drivers be damned!

 

Ok... So I now have an engine which was rebuilt about a year or so ago, and I now have a rebuilt transmission and a transfer case with less than 45K on it. Everything is running Mobil 1 Full synth, including the rear Diff...
On the highway, I am getting 18 to 22 miles to the gallon. I regularly clean the iacv and the MAF Sensor, I use a K&N air filter which I clean regularly...
The problem I am seeing is this vehicle has a 4 speed automatic, which BLOWS!! At 65 miles an hour the engine is humming along at 2700 RPM. Oh well. I guess I need to get something else for my 40 miles one way highway trip to work.

 

I've had my RX since April 13th. I reset the Avg MPG at that time and currently I'm averaging 19.9mpg. However, I was driving like a bat out of hell for the first week and now I am keeping it on cruise at 70mph. It's slowly creeping back up. I think 70 is the "sweet spot" for my RX. It seems to get the best instant MPG at that speed on the highway.

What's sad is that I came out of a 2007 GMC Acadia (much bigger vehicle) and it got better gas mileage than the RX does. Oh well, it's not awful, so I can live with it.

 

Just came off a 2500 mile trip, mixed Interstate and two lane roads, averaged about 21.5 mpg with a mix of 85 to 91 octanes. No complaints. Got up to 23 on one Interstate stretch. Year 2000 w/120K miles.

 

Hey Bears,
Sorry top hear about your rebuilt woes; is there an overdrive feature that is now missing or one of the gears removed from the tranny? When I first got my RX I wanted to see how fast I could get it on a very rural highway and I reached 125, then it did something most unexpected... it shifted gears!
I wonder if you're missing one of the higher speeds or your overdrive has been altered in some way.
That said, the best I've ever averaged was on the same trip, all highway, at about 23 MPG. I just this week followed all of LexMex' advice (MAF, tire pressure, water wetter, etc.) so I'm excited to see if this makes even a slight change.
Mine is a 2000 AWD and love it! Also just added new headlights and it looks 10 years newer and I am sure will get an extra 5 MPG (by reducing headlight fluid emissions).

 

I just purchased my rx300 and drove it back from Houston, Texas to Dallas, Texas. The display mileage never got over 19.9 but calculating by fuel consumption, I showed almost 22. I will be checking into possible improvements but this seems to be decent mileage for the weight, power, and equipment on the vehicle.

 

Welcome to Club Lexus!

Did you reset the mpg before the drive home? That may have been why it didn't change the mpg much.

I've noticed the computer to be within .3 mpg of the actual mpg.

 

While your blue info screen is displaying the mpg information, hold down the INFO button for a few seconds; it will reset the mpg information.

For the record, I averaged a little over 23 mpg this past week, with about 75% of that on the highway at 65-70 mph, and the rest in-town driving.

 

Right after I replaced my Air/Fuel ratio sensor, I was getting a little over 30 mpg on the freeway (going about 75 mph). It dropped to a "normal" reading within a day or so, back down to around 25 mpg.