Gas mileage

So if a lighter vehicle gets better gas mileage, should I never fill up my gas tank all the way to full? Just wondering

I just seen on TV the other day, special on How its made I think. You should fill up when you get down to half a tank. The reason being the more room in your tank, the more you will lose to evaporation.

Backhoebob said:

I just seen on TV the other day, special on How its made I think. You should fill up when you get down to half a tank. The reason being the more room in your tank, the more you will lose to evaporation.

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This goes more in depth on some of the common myths and in all honesty, the great consensus is you may save a few pennies if you do everything perfect, other things are better for your gas mileage, like proper tire pressure, good shocks, etc.

Check out hyper mileage threads. These are the worst people to sit behind after the light turns green. They are the same people that will drive 25mph in a 35 mph zone because of the timed lights. If you drive 40 mph you wont have to stop at the light. Which method saves gas?

In college I knew a guy who stripped everything he deemed unnecessary out of his car (2 or 3 years old) so he could get better mileage. I don't know if it actually did him any good, but we used to get a good laugh, seeing him in his car with only a drivers seat. This was back when gas was $1 or under, I bet he is $hi77!ng a brick at today's prices.

Backhoebob said:

I just seen on TV the other day, special on How its made I think. You should fill up when you get down to half a tank. The reason being the more room in your tank, the more you will lose to evaporation.

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I thought today's cars recaptured that evap and feed it back into the airstream when conditions are good for it. I can't recall what the system is called.

Man I wish I got better mileage with my pickup. 454 engine with 4/10 gears in the rear gives me 8 mpg on the interstate and about 10 mpg in town driving. Same if I am empty or towing a trailer just crap mileage.

It does do a good job though towing

Two vehicles. A Mini for back and forth to work - (no interstates, just 45mph streets, 8 miles) so 32mpg city is nice. Half a gallon a day. Then the SUV for hauling friends, cargo, etc. I found I use the SUV a lot less than I thought I would.

I think it would just be a matter of pennies. On a side note, like Hang Glider, I went the two vehicle way. A truck for when I need it (paid off for years now) that gets horrible MPG, and a Chevy Curze Eco. Use the car to drive back and forth to work. About half interstate and my average is 36.5 MPG. Love that friggin car, especially cause its made in Ohio and can compete with the hybrids. After spending 70+ buxs a week driving the truck back and forth to work....I now giggle and flip the gas stations off on the way by!

Homercidal said:

I thought today's cars recaptured that evap and feed it back into the airstream when conditions are good for it. I can't recall what the system is called.

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It's a charcoal canister.
And, yes, a "leaky" gas tank will trigger the "check engine" light.

Trying to drive out of the bottom half of your tank leads to more frequent fill-ups, which means more stopping, which means worse mileage.

Besides 10 gallons of gas weighs 80lbs-ish. You car weights +3000lbs. 80lbs doesn't make a lot of difference in gross vehicle weight.

Proper tire inflation & clean air filters will save you a lot of mileage. Don't accelerate hard unless you need to.

If you get geeky about it, find a route with a 40 - 50 mph speed limit because most cars get their best mileage around 45 mph. Faster than that, you are loosing mileage to drag.

And if you have an automatic, you can set cruise control anywhere over 25 mph.

In my car, I get 5 - 7 mpg better than my wife does because she is an insanely aggressive driver.

^ Same here. The wifey is all gas or all brake....

Homercidal said:

I thought today's cars recaptured that evap and feed it back into the airstream when conditions are good for it. I can't recall what the system is called.

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They do. It's a closed system.