MPG does not match miles driven

[radereb]

I know the MPGs are a little off on the screen but it usually shows 48-52 MPG but I only get about 400 miles on a tank of gas. I am not a mathematician but that doesn't add up.

[samwichse]

And how much gas do you put in after this 400 mile tank?

Some important info missing from this post.

Sam

[jonnyvtec]

Just fill up twice, preferably at the same pump until the first click. That will give you a controlled amount of fuel that you can divide into the range you get. You can then see how accurate your computer is.

[radereb]

Originally Posted by samwichse

And how much gas do you put in after this 400 mile tank?

Some important info missing from this post.

Sam

It was roughly 8 gallons

[samwichse]

Originally Posted by radereb

It was roughly 8 gallons

400 miles / 8 gallons = 50 miles/gallon.

Seems like it was dead on for you (most people it's ~2mpg too high.

[radereb]

Originally Posted by samwichse

400 miles / 8 gallons = 50 miles/gallon.

Seems like it was dead on for you (most people it's ~2mpg too high.

Do you ever get close to your range? Mine usually says 550 miles or so and I never come close.

[samwichse]

I don't have a range, I've got a 2004 Civic Hybrid. All I get is the instant/average MPG.

You could get close to that range if you ran your tank completely bone dry.

With a 10.6 gallon tank, 50 mpg gets you 530 miles until your car rolls to a stop. I always fill my tank with about 1.5-2 gallons left in the tank, cause I like some safety margin.

Sam

EDIT: My car has a larger 13.2 gallon tank, I usually put around 11 gallons in it at 500-550 miles (45-50 mpg)

[coasterdevils30]

A little disappointed, just filled up the tank for the 2nd time so I could get the exact MPG. Got 45.4 MPG w/ a fill up 7.299 gallons. Pretty good considering it was all city, no HWY... but the MID was showing a tank avg of 49.7.

I guess I cant complain too much, I am beating the EPA's estimates by a good bit!

[procupine14]

Yeah, I never trust the dash gauge. Mine hasn't been accurate on a single tank since I purchased my insight. I track my fuel mileage on Fuelly because I can text my fillups in and it keeps track for me. My average this winter has been about 42.6. It's been pretty cold here and driving around in two snow storms sent those two tanks into the high 30s.

However, all of my tanks on the MID have reported in somewhere in the 46 to 50 range without fail.

[coasterdevils30]

Think I may have caught part of the problem for the lower MPG. I checked my tire pressure today and the front tires are at 33 and 31PSI. Rear tires are at 30 and 30.5. Gonna up them for sure, hopefully that'll help a bit. I've looked at some of the tire pressure threads. What would you recommend putting mine to? I have the stock 2010 dunlops