This may be a crazy way of thinking...but would you get better MPG's by say only filling up only to 1/4 due to weight?

A gallon of gas weight 6 lbs...So my tank is 16 gallons..if i only filled up to 6 gallons...i would be saving what 60 lbs..is that something that even would matter...i know weight matters in MPG's, HP ect...but is 60 lbs really anything?

Of course it would suck filling up everyday but i am just wondering if you did this for say 2 months..would you notice anything

yes you would get better gas mileage but I think the difference would be sooo small that you might not notice....ex. extra mile or two per tank

better thing to do is to drive smoother and not go more the 50% throttle....I did that and got an extra 50 miles out of my tank!!

My car was getting about 15-16 MPGs but i was having fun with it because i only got it about 3 months ago. Next tank i am going to take it very easy to just see how much more you can get from a tank..i was only getting 300 per tank..i want to see if i can get 350


When they figure a car's MPGs before it hits the showroom..do they figure that with a full tank of gas?

lol I get the same, typically 300 miles before the light comes on. But then I went easy on her and got 355 miles before the light went on. But I have to let you know driving it like that was hard, car is so much funner to drive if you don't worry about mpg

It's a 20 gallon tank.

oops


So full tank weighs 120 lbs..only put in 6 gallons you are down to 36 lbs

i think the difference would be so minimal that you wouldnt notice it.

I've personally gotten 415 miles on one tank driving from PHX to SD.. Could have gotten more but didn't want to risk it.. ~~ That was with mashing it in 3rd to the end of 4th 3 times on the highway when the light came on.

In pure city driving I've gotten 380, again, could have gone more but didnt want to risk it- This was HARD. I was accelerating very very slowly and didn't go over 2000 rpms except for once accidentally.

Lol, the mpg savings would be so minimal its not worth it.

I got exact same mpg with a half tank and 1/4 tank. I tried this driving from Texas to Oklahoma to see exactly what you're asking about..the weight of gas. I was cruise controlling 80 mph both times and both times I came out to 25mpg. lol

I noticed once i threw mods on i threw my gas mileage out the window. Driving in chicago traffic with a 6mt is brutal enough, taking a look at the gas gauge makes it worse.

i thought it was a 15-17 gallon tank

I think a gallon of gasoline at 72 degrees F weighs around 6.25# per gallon. As it cools it became more dense and heavier, as it heats up, it weighs less (learned this in a recent court case).

The difference would be negligible; however, if one was OCD about it, it would require looking at various variables:

• the more fuel, the less evaporation-- in general: BUT--
• the more fuel, the more gas it takes to accelerate the weight (Newton's 2nd Law of Motion), so in town a 1/4 tank would be more efficient
• once you reach your speed, Newton's 1st law of motion kicks in (object in motion tends to stay in motion...), so a full tank would be most efficient if there are not frequent stops

This an extremely abbreviated argument, others who know much more about this than me can tease it out better.

As a point of comparison, my AT sedan typically gets around 21 mpg in normal driving, mostly hwy at 55 mph. Revs between 2-2.5K. Not great but acceptable.

55...10 MPH below speed limit!?