How does the gas tank average work? If I have 1/4 tank and I've been driving in the city then I fill it to the 1/2 mark and now hit the expressway, will my average change because I added gas or because I'm now driving on the highway and, therefore, getting better mileage?
OAKPLANK

 

Oakplank, good question. I am not sure myself. All I know is when I have filled up my tank, the tank average resets.....I will monitor this post to see if anyone else knows.

 

Oak...LOL @

Once the tank avg is reset by adding gas it works from that as new tank so prior calculations are gone, so yes you could then hop on highway and impress yourself with MPG.

For kicks between fill ups you could learn to reset your avg mpg on the fly and reset it just as you are getting on the highway too. all you do is hold in scroll/reset button until it zeroes out, then let go and be impressed

 

ES350BOB, Are you saying that I can reset my tank average? I'm able to reset my trip average but have not been able to reset the tank average.

Also, do you need to completely fill your tank for it to reset or does it reset as long as you add gas, no matter how small the amount. Do you think that the reset happens every time the gas cap is removed?

OAKPLANK

 

Your tank avg resets whenever you add gas to the tank I suspect enough to move the float in the tank for it to recognize some gas has been added. Every time I added gas whether 10 bucks or topped off 5 or filled it up it would reset. Have it, tank avg, up showing when you pull in for gas, then afterward you will see it reset itself when you have started the car after adding gas.

The avg mpg you can reset while driving simply by having it appear and then press and hold until it resets.

Either of the above would give you the
if you got right on a highway after doing either.

 

ES350Bob,

You are saying "The avg mpg you can reset while driving simply by having it appear and then press and hold until it resets."
I agree with that. I've done that. However, if "TANK average" is showing and I press and hold, it will not reset. The Avg mpg can be reset but not the tank avg. At least not on my car.

OAKPLANK

 

Tank avg only resets by adding gas and it is automatic so you should have seen it change by having added gas to your car whenever you have.

Like you were saying, if you did a lot of city driving, you could add some gas, it would reset then get on highway right after.