My 11 RX350 has roughly 4200 miles so far and the Average MPG reading was relatively stable in the range of 17.2-17.6. A strange thing happened this afternoon when I drove my car on a local road. The Average MPG was suddenly jumped from 17.2 to 25.0+ in zero second. I then stopped the car and turned off the engine. I restarted the engine in 5 minutes and slowly drove it. I noticed that the mpg reading was jumped down to be as low as 14.5 and then jumped up to 15.0, 16.0, 17.0, 18.0 and then down to 17.0, 16.0. It's really puzzling since all of these changes in the mpg readings happened in a half-hour's driving.

Did anyone experience a similar issue with his/her RX? Is this a big issue and what action should I take to resolve it? Thanks

 

There are two different mpg displays. Average for all miles driven and average for the current tank of gas. Toggle switch on steering wheel changes the setting.

 

^^ same as above plus ... if you reset the average by pressing the toggle switch on the steering wheel, your mileage could jump around like you described very easily.

 

The jumped mpg that I mentioned in my first post is for all miles driven. The current (tank) mpg was shown as the same reading while the all mile mpg were changing constantly.
I didn't do anything with the toggle switch while I was driving and suddenly seeing the strange jumping.