Your Gas Tank: Do You Top Up or Not?

[QuarterSwede]

Yeah, when you put it like that, you know, using facts and stuff, it does sound silly but I swear I've heard it from a few people. Maybe they are so old, it was before fuel injections. The NJ law is great in the winter but sometimes, in a rush, its silly. We still have much cheaper gas then other states, though. Probably be even less if they didn't have to staff the pumps.

There are a lot of car myths that don't apply to modern cars. It's funny how a lot of those hang on even after technology has moved on.

Ex. Automatic transmissions use more gas than a manual. That used to be the case when automatics were new but nowadays it's the exact opposite since automatics are much more efficient at switching gears than humans.

 

[millerj123]

I always fill up. I check prices of stores on my normal routes, and will go a small distance out of my way for a much better price. But, it doesn't make much sense to drive across town for $.02 difference per gallon when it's $2.60 a gallon. $.02 for 20 gallons is only $.40 cents savings on $52.00.

 

[jav6454]

I generally top my tank off... although a 25 gallon tank that needs premium is one hell of a hit, especially at 7-8mpg around town.

Oh wow...

Well, back on topic. I normally fill up always, unless I know there is a gas price going down curve. I usually fill in about $10 and when need be another $10, until the price stabilizes. That way I maximize gas return.

Other than that I always fill up and never let the gas tank be less than 1/4. I always think that the 1/4 is emergency fuel; just in case.

 

[steve2112]

There are a lot of car myths that don't apply to modern cars. It's funny how a lot of those hang on even after technology has moved on.

Ex. Automatic transmissions use more gas than a manual. That used to be the case when automatics were new but nowadays it's the exact opposite since automatics are much more efficient at switching gears than humans.

Yeah, with electronically controlled transmissions you can match the transmission to the engine much better. Also, modern autos often have more gears than manuals. Some of the luxury brands like Lexus and Mercedes have 7 or 8 speed autos.

With all that said, I'd still rather drive a manual.

 

[Mac'nCheese]

There are a lot of car myths that don't apply to modern cars. It's funny how a lot of those hang on even after technology has moved on.

Ex. Automatic transmissions use more gas than a manual. That used to be the case when automatics were new but nowadays it's the exact opposite since automatics are much more efficient at switching gears than humans.

That makes sense to me. I bet people still do oil changes before the newer synthetic oil really needs changing.

 

[QuarterSwede]

That makes sense to me. I bet people still do oil changes before the newer synthetic oil really needs changing.

Could be. I've yet to switch to synthetic. Not sure why really other than that I've heard you can't go back to regular. Why I haven't changed makes no logical sense to me since synthetic is widely available ... maybe after I use up the last of my oil and filters.

 

[iMpathetic]

Oh wow...

It isn't even a truck or anything like that.

Regular is supposed to be used with this engine, but... it's more like 6MPG on regular.

 

[yg17]

I always fill up, I'm not going to inconvenience myself and stop at a different station later because gas might be 5 cents cheaper there. I usually end up filling up each Sunday and that lasts me throughout the week.

 

[bobr1952]

I always use a credit card so I just keep pumping until it shuts off then I'm done. I don't usually pay attention to how much gas I put in--I do notice the price though.

 

[VPrime]

Could be. I've yet to switch to synthetic. Not sure why really other than that I've heard you can't go back to regular. Why I haven't changed makes no logical sense to me since synthetic is widely available ... maybe after I use up the last of my oil and filters.

If your car has a higher milage you don't want to switch to synthetic.
The reason being is, the "dino oil" creates sludge, and this sludge could actually be preventing leaks. When you switch to a synthetic it could clean out a lot of gunk and then all of a sudden you have leaks.
If you have a car that is fairly new with low milage switching isn't an issue...

 

[iJohnHenry]

In Canada of old, you never let the gas get below half, in the Winter.

Think stuck in a blizzard for the first reason.

For the second, the older tanks were not sealed, so the more air inside, the more condensation, when going back and forth, between heated and unheated parking.

 

[FrankieTDouglas]

Depends on where I am. If I'm in Maryland/Delaware and I'm on empty, I'll put $15 in. Sometimes I just fill it up. No real reason, except maybe it's a holdover from grad school days with limited funds. If I'm in New Jersey, I'll always fill up because their prices are so much cheaper. If I'm in New York, I'll try to wait it out until I'm in NJ, but if I'm on empty I will get $5-10 worth, until I'm out of the state.

 

[quagmire]

I am pretty much on a routine for fuel fill ups. I only fill my car up with Shell gas, I always fill it up until it automatically stops, and I always refuel when the indicator says I am at a quarter of a tank( which is 5 gallons left for me) as the reason already mentioned that the fuel pump uses the gas to cool and lube itself. I only brought it down to the fuel light( 2 gallons remaining) once.

On another note, I do find it funny how people complain about the price of premium over regular gas. I have only noticed a difference of around $4 between regular and premium. If you can't afford the extra $4, then stop buying Starbucks everyday and start brewing at home and you'll have the money to put the proper gas in your car.......

 

[dukebound85]

I fill up every time. Why not, adding a little bit just means I'm going to need more soon.

same. In the 10 years I have been driving, never have I not filled it all the way

 

[SkyBell]

I don't usually have enough money in my bank account to fill my 16 gallon tank in my Escape. Or anywhere close, for that matter. Cheers for being broke, eh?

You'd think a smaller SUV like that would get acceptable mileage, but 15 MPG seems to be the best it can manage. Which really isn't enough for me, hopefully getting rid of the thing in the next couple weeks and getting something smaller. It's been nothing but a rock of reliability for me, but alas, we must go our parting ways...and it can be a rock for someone else.

 

[QuarterSwede]

If your car has a higher milage you don't want to switch to synthetic.
The reason being is, the "dino oil" creates sludge, and this sludge could actually be preventing leaks. When you switch to a synthetic it could clean out a lot of gunk and then all of a sudden you have leaks.
If you have a car that is fairly new with low milage switching isn't an issue...

I'm glad you mentioned this because I've got 115K on my car now. I'll definitely stick with the natural stuff. Thanks!!!

 

[yg17]

I am pretty much on a routine for fuel fill ups. I only fill my car up with Shell gas, I always fill it up until it automatically stops, and I always refuel when the indicator says I am at a quarter of a tank( which is 5 gallons left for me) as the reason already mentioned that the fuel pump uses the gas to cool and lube itself. I only brought it down to the fuel light( 2 gallons remaining) once.

On another note, I do find it funny how people complain about the price of premium over regular gas. I have only noticed a difference of around $4 between regular and premium. If you can't afford the extra $4, then stop buying Starbucks everyday and start brewing at home and you'll have the money to put the proper gas in your car.......

There's no reason to buy premium if your car doesn't require it, it is a complete waste of money. And if your car requires premium, you should've been aware of that when you bought the car and shouldn't complain. You gotta pay to play.

 

[quagmire]

There's no reason to buy premium if your car doesn't require it, it is a complete waste of money. And if your car requires premium, you should've been aware of that when you bought the car and shouldn't complain. You gotta pay to play.

That is what I meant by putting in the proper gas. If your car recommends premium, then put premium in it. It is only a ~$4 difference and stop buying starbucks every day and you'll be able to afford the difference. I notice this difference due to filling my Aura which recommends regular and filling my dads 335xi which recommends premium. Both have 16 gallon tanks and I refill them at a quarter of a tank.

What I wonder is if the reduced fuel economy by putting regular in an engine recommending premium ultimately washes out that $4 difference. Has there been a study about it yet?

 

[Hisdem]

I always fill it to the top. I had to sell my Grand Cherokee V8 a couple of years back because I couldn't afford fueling it and paying $100 every week.

But now I am really happy that my Fusion is averaging 11km/l (26mpg), while still having decent power output.

 

[Rodimus Prime]

Shear laziness is what controls how I get gas. I hate having to stop to do it so I try to do it as little as possible hence fill to the top run to gas light (long distance driving is the exception. Then I either have preplanned stops or 1/4 of a tank I start looking. Preplanned ones are on a known route so I more often will push it farther knowing the place is well within my cars range.)

I always fill up my car until it clicks off then wait about 5-10 sec then do another shot until it clicks off. Normally the 2nd shot nets me an extra 1/2 gallon. I honestly see no point to only fill up a car 1/2 way or less. Any so called extra gain in MPG from the reduced weight is going to be loss in the extra stopping to get gas. Lets face it 5 gallons of gas is less than 30lb which is at most around 1% of cars weight or less. At cruising speeds that extra mass has even less effect. Now most of the time I drive until my gas light comes on (2 gallons left) and fill up then. 2 gallons left means I have around 40-50 miles left in my cars range and that is plenty for a day or so. Besides short filling up means I have to stop more often and does not effect how much gas I burn. That is controlled by how far I drive so like I said I always fill up to the top.
As for filling up when I was working I would make a mental note of the 3-4 stations on my route home and then stop at the cheapest on my way home which generally was an Exxon stations on my right. Hell for me not to use that station it would need to be around 3-4 cents less somewhere else because all the others I would need to turn left to get to and the Exxon stations had a free ATM in it.

If your car has a higher milage you don't want to switch to synthetic.
The reason being is, the "dino oil" creates sludge, and this sludge could actually be preventing leaks. When you switch to a synthetic it could clean out a lot of gunk and then all of a sudden you have leaks.
If you have a car that is fairly new with low milage switching isn't an issue...

umm just might like to point out that most oil you buy today is pretty much synthetic and recycled at this point in time. Also from what I have read there is no real gain about spending the extra money to go to synthetics now days.

 

[duncanapple]

That is what I meant by putting in the proper gas. If your car recommends premium, then put premium in it. It is only a ~$4 difference and stop buying starbucks every day and you'll be able to afford the difference. I notice this difference due to filling my Aura which recommends regular and filling my dads 335xi which recommends premium. Both have 16 gallon tanks and I refill them at a quarter of a tank.

What I wonder is if the reduced fuel economy by putting regular in an engine recommending premium ultimately washes out that $4 difference. Has there been a study about it yet?

I have actually read a lot of articles lately that say if the car calls for premium, its really optional. If you elect not to put premium in you aren't hurting the car - at worst you are giving up a 5% or less in horsepower and nothing in MPGs. Even in a 300 hp car we are talking 15 hp which will not be noticeable. Premium gas tends to be "recommended" in higher compression engines to avoid "knock." Since modern cars have pretty sophisticated knock sensors that detect this and retard the timing (hence the ~ <5% loss) it's a non event.

On the other hand its not a huge difference in the price of a tank. The real savings is probably prevalent when you drive a lot of miles per year (say 20K like I do), your car gets lackluster economy, and the price of gas is high (like a couple years ago when it was >$4 a gallon - the percentage difference between 89 and 91 in price can start to become a significant amount).

But don't just take my word.. here is some backup data... http://www.usatoday.com/money/autos/2003-07-30-premiumgas_x.htm

But back to the OPs question, I try to fill up every Sunday regardless of where the level is, or if I get down to an 1/8 of a tank or so. If I know we are going to get snow or a bad cold snap I will also fill up because who wants to freeze their tail off pumping gas I agree with the above, regardless of how much $ you put in the tank, you use what you use and you aren't really saving anything by not filling it. Even the price swings are not enough to justify not filling up. If gas went up 15 cents in a week, you only save $2.25 on a full tank. Assuming you still need to pump SOME gas, perhaps a half tank, then you have really only saved about a buck.

 

[184550]

I normally put in $12 worth (about half a tank, a little less) on Monday or Tuesday, which is usually enough for the entire week.

 

[dmr727]

I always fill up, I'm not going to inconvenience myself and stop at a different station later because gas might be 5 cents cheaper there. I usually end up filling up each Sunday and that lasts me throughout the week.

I'm like this. I'm lazy, and will happily pay a little extra to support my lazy lifestyle. When the car needs gas, I stop at the whatever station is closest and fill her up.

 

[Nugget]

I always fill to the top because I like to track my gas mileage (15.81mpg on the street, 7.80mg on the track).

 

[QuarterSwede]

I have actually read a lot of articles lately that say if the car calls for premium, its really optional. If you elect not to put premium in you aren't hurting the car - at worst you are giving up a 5% or less in horsepower and nothing in MPGs. Even in a 300 hp car we are talking 15 hp which will not be noticeable. Premium gas tends to be "recommended" in higher compression engines to avoid "knock." Since modern cars have pretty sophisticated knock sensors that detect this and retard the timing (hence the ~ <5% loss) it's a non event.

On the other hand its not a huge difference in the price of a tank. The real savings is probably prevalent when you drive a lot of miles per year (say 20K like I do), your car gets lackluster economy, and the price of gas is high (like a couple years ago when it was >$4 a gallon - the percentage difference between 89 and 91 in price can start to become a significant amount).

But don't just take my word.. here is some backup data... http://www.usatoday.com/money/autos/2003-07-30-premiumgas_x.htm

You've got to be careful because some cars run badly (I'm talking about possibly damaging) on regular when they say to use premium. My mother's Maxima is an example. She put regular in it once and it ran pretty rough (to the point that we were hoping it wouldn't damage the engine). Of course, the manual doesn't just recommend premium, it actually says to use it only.