michaelo

How would he know when is the next time to fill up if the 'electronic gizmo s not working properly?"

dkmesa

If you consumed 1/4th of 16.9 gallons in 44 miles, you'd be averaging less than 11 mpg. Of course 2 days of driving is not nearly enough to draw a conclusion about your mileage, but if you are worried about how much fuel you're burning after driving 44 miles with a new car, you clearly should have bought an economy car.

venom51

I am 100% responsible for the poor gas mileage of any of my vehicles..

Voyager6

Fill the tank all the way up, drive it some safe amount. Let's safely assume 10MPG. Return to same pump, refill and divide mileage traveled by gallons and you have a good indication of fuel mileage. If the trip mileage and MPG agree then the TFT can be reasonably trusted. If not, there is a problem. If you travel a known route, you can compare calculated miles to what the car says.

For best accuracy, the right size and type (Summer/Winter) of tires should be picked in the TFT. If the wrong tires are selected, the displayed mileage and resultant TFT trip mileage and MPG could be off by a couple percent.

When you fill the car up, the fuel level in the TFT should go to full. If not, there is an obvious error. Before refueling, compare the fuel level indicated to the full tank amount minus the amount it took to go to full again (Note that indicated tank levels are never perfect). Over time, take the car down to 1/4 tank and then compare the amount to refuel. At that point, repeat but let the indicated fuel level go to the upper of the red reserve area. If all is close, you can trust the indicated mileage to empty and the levels.

V6

WestlakeHorn

billwot

Back in the olden days (like, maybe early 2000s) we used to actually measure/calculate fuel mileage, then we really knew what at actual fuel consumption was.

We would 1) fill the tank and zero the trip odometer. Then 2) we would drive until we were down to maybe a 1/4 tank or less,, then 3) we would fill the tank, and note the amount of fuel required to fill the tank. Then 4) we would divide the miles driven (from the odometer) by the gallons needed for the fill (from the gas pump display) and we would actually know miles-per-gallon.

BTW, that is the same basic procedure that the EPA uses!

2014BoxsterSBoy

please delete

bminingham

I just looked at my mpg yesterday because of this thread and I am getting a little over 20 on average. I don't drive around slowly in my car at all, and always bring it to redline at least 4 or 5 times when I am out driving. Most of my outing are just to drive, and long highway trips are rare. So that said, your mpg seems low if you aren't being really aggressive out on the roads..

Fined

From the Cayman it can't be more than 20mpg around town, probably more like 17. Right now I've got it torn apart to do some A/V upgrades, so in the 911 I'm getting 13mpg around town. Ha! Driving it properly I'd say.

2014BoxsterSBoy

please delete