My new-to-me 2006 RX has the standard information computer (no NAV). It seems fairly useless. Is there a way to compute miles per gallon over multiple tankfuls? Even over more than one start and stop driving cycle?

 

Short answer, nope. Our previous IS 250 AWD (since traded for a GS AWD) had a readout for milage to date (total mileage), but that isn't available in our info computer RX's. And you are correct, it is fairly useless, other than to measure current (single tank) fuel mileage, and the wild a** guess as to remaining distance.

 

Stupid. Worthless. Why bother?

 

On long trips we have found the trip computer to be reasonably accurate in regards to gas mileage, although on our RX it has proven to be a little (<1 mpg) pessimistic (always shows a bit lower than hand calculating). Also the distance till empty has been a good reminder. Otherwise, I keep mine on current average fuel mileage and really don't bother much with he other functions. Actually other than fuel mileage, I rely on my Garmin 660, which provides a lot more info than the standard Lexus GPS, allows inputs while on the move, only cost $299, and it's portable!

 

I also am a big fan of the portable GPS (I use a TomTom) over the Lexus unit. I have the Lexus unit in my 2007 LS460 and hate it. It's convenient when I need it on the fly, but I usually keep my TomTom handy for any real travel.

Back to the nearly worthless trip computer. I find that I like it on "miles to empty"...the instantaneous and average (during that trip) MPG is annoying.