GX 470 Average MPG on Trip Computer
 

That readout isn't very accurate at least on my 04 GX (it tends to show better mpg than I actually get). I keep track and calculate mpg based on actual miles and gallons used - getting about 15 to 16 in town, and 18 to 22 on freeway driving depending if I drive 65 or 75 mph. Sporty driving can make those in town mpg numbers a lot lower.

Also keep in mind that you have a new car with an engine that needs to be broken in. When I got my IS350, it was a consistent 15mpg for a few thousand miles. Now I'm consistently getting 22mpg!!

14.7 MPG on computer with a mixture of 60% city and 40% highway. I only use regular unleaded fuel 75% of the time as well. Every 4th tank I use premium.

My actual experience on my 2007 GX470 has been to average about 19mpg with a mixture of 70% highway/30% city driving though the computer says it's getting 20.5. My observation - and that of others I've spoken with - is that Toyota/Lexus fuel economy digital displays tend to be about 1.5-2.0mpg optomistic.

As was previously stated, any new vehicle will perform with abnormally low mpg figures for the first few thousand miles until properly broken in.

Mine's scarry accurate!
 

The 2005 GX 470 has been with our family about three weeks. Leg one, 100% freeway from Anaheim to Las Vegas, @ about 75 mph, 18.5 mpg on the meter, 18.48 hand calculated. City driving is about 15.5. I had one city tank where the read out was almost 1 mpg optimistic, but the others were with in a couple of tenths. Our 2002 LS 430 is so accurate that it always amazed me, and made me wonder why my two year newer Dodge truck couldn't get within 1.5 mpg, ever. I guess I asssumed that lessor vehicles use a calcluation that does not track total fuel flow, perhaps some input that is tracked by OBD II anyow - average throttle position sensor cross-referenced to speed and engine run time, plugged into to assumed fuel consumption based on some chart from the factory. The only way that Toyota could be so close would be to measure actual fuel flow, the sort of info gathered in larger boats and aircraft for totalizer and gph readouts. That's all speculation on my part, and I guess I should do some Internet research to find out. I guess I don't care, as long as it works so well! I've always thought that Toyota has it's act together in this regard. Does anybody pay attention to their average mph figure? It has an amazing correlation to mpg, understandably so. My 15-ish mpg tanks have average mph in the low 20's, while those approaching 19 mpg are showing close to 50 mph average, or more. Stoplights and idling really hurt! Anybody ever try to see how far past zero you could go on the range indication before running out of fuel?

Trip Computer Avg
 

I average about 20.5 MPG on my trip computer and when I actually calculate my total it is about 19.5. I am about 50% highway and 50% city. I only use premium non ethnol, I have been told that non ethnol will extend the life of my motor (we will see). Any time i drive more then 65 mph my gas mileage goes way down.
I have a 2006 and just had my 30K maintaince done

Your gas mileage may vary
 

Gas mileage varies between drivers with a lot of variables. I have attached my mileage log that I keep. I have had my GX for 15,000+ miles. In the notes column the avg mph, avg mpg and elaptised time has been recorded. This is info. from the car computer. I hope to someday graph the variable of mile, et and mph.

I think I know is my trip computer is optimistic.