Carla748

I have a brand new 2013 RX 350 and I'm interested in how many MPG I'm getting.

My car monitor says 18.7 average mpg, and also says 21.1 mpg since last fill up. I only have 435 miles total since purchasing it 10 days ago. I understand the mpg since last fill up- but how is the "average mpg" determined by my car? We filled up Saturday and drove quite a bit of freeway.

UCSB

Average is a running average of your mileage. Unlike the MPG since last fill-up, this average will continue until you reset it. You can reset it at any time by pressing and holding down the ENTER key on your steering wheel (while Average is being displayed) until you see it reset to 0.0. It is available for your use. Some people don't reset it and let it continue. Then it will give you a total MPG as long as you have owned your car. Other people reset for their own purposes ... like getting their total MPG during a trip. Right now it represents the MPG you have gotten over the 435 miles you have driven. If you don't reset it, after a few thousand miles it will give you a good approximation of what to expect in terms of MPG for the car and your typical driving. MPG may drift up a little after you have a few thousand miles on your car.

Carla748

Thanks UCSB!

Now I understand it

markrivers

UCSB clearly explained the difference between the two.
Now, some real road application, i prefer to use the average mpg more than the "last fill up ".
If you do short trips with lots of stop and go and no freeway. you 'll never see the " last fill up" move above 20mpg.

rxsuperman

I have a habit of always monitoring my "MPG after last fill up" and try to beat my previous best reading. So far, my best MPG after last fill up is 28.5MPG on my 2011 RX350.