My Charger does that. From full to 1/2 I always get 200-205 miles, from 1/2 to E I get an additional 130 miles. I never get more than 330 miles on a tank. The why’s have crossed my mind several times but I dont beat myself up trying to understand it. As gas prices go up, I might start wondering.
transman
“The why’s”? At what point did you rule out the possibility that your gas gauge is inaccurate? U n33d !m0r3 Ys. L0L.
It’s true! The bottom half of the gas tank capacity does go faster, but when it reaches the EMPTY mark a guy can drive forever! Why?
I’ve been driving 53 years and every car I’ve ever had drops faster on the bottom half of the tank than the top. I accept it as just the way tank is built and the gauges are set in the tanks. I agree that the more weight carried in the car, the worse the mileage. It’s a fact of life.
Here’s my related question that arises between by wife of 46 years and me: I say it’s bad for the car, and perhaps the mileage, to draw gas from the very bottom of the tank and the crud that’s there and the water that collects in the more empty tanks. Am I right or wrong? (C’mon guys, I need help on this one. I hate seeing the fuel gauge riding at almost empty, especially during the winter.)
Thanks.
It appears to be mostly by design, and I think (although don’t know for sure) that the clearance of the float also contributes to this.
With my car (a 2004 Mazda 3), I have a 14.5 gallon gas tank. When the gauge shows exactly empty (it’ll go past E if you give it time), it’s about 12 gallons to fill the tank, so I still have 2.5 gallons (about 75 highway miles, in theory) of leeway. It looks like the low fuel light goes on when I have about 3.5 gallons left. I’ve never let my car run out of gas, so I don’t know how close a refill will get me to the 14.5 gallon capacity, but it’s clear there’s plenty of leeway.
I would venture to guess that the amount of mileage you get from F to 1/2 in my car is almost the same as from 1/2 to empty (true empty, not just ‘E’ on the gauge), but I’ve never ventured to find out. I’ve observed that if I make it to 200 miles when it hits 1/2, that I could expect to go another 200 before needing to fill up. Perhaps the Mazda’s gauage is more accurate.
You would be surprised at the crud and water at the bottom of the tank. Also more gas keeps the in- tank fuel pump operating cooler, thus prolonging fuel pump replacement.
Doesn’t all the fuel get drawn from the bottom of the tank? How could it come from any other place?
Doesn’t all the fuel get drawn from the bottom of the tank? How could it come from any other place?
What the hell does this have to do with “the female mind”?
Good point geekmaster.
Something to consider there.
If I had a choice of the guage having greater accuracy on the full end or on the empty end, I’ll take accuracy on the empty end.
Bing! Bing! Bing! Winner winner, chicken dinner!
Exactamundo!
But there are a lot of highly valued 250+ posters here who you might offend if you ask to many questions along this line, and your posts will be moved to the dreaded Moderation Queue.
Hmm. What about fuel pressure? Might a fuller tank help the fuel pump along, thus requiring less energy from the battery, and secondarily the engine? 
I have noticed the exact same thing happening in my car. I don’t think it affects my mileage, but it definitely is noticeable that the gas gage drops much faster past the halfway mark. Science aside, it definitely happens!
When the price of gas is rising, tomorrow’s gas will cost more than today’s, so you should buy gas more often, and keep it topped off.
When the price is falling, tomorrow’s gas will be cheaper, so wait as long as you can before you fill.
As with the weight arguments, this will save only a dime or two per tank.