Fillups?

[nineteen8t6]

Hi!

I'm a fairly new 07 Versa SL owner. I've had the car for about 6 months or so. I just have a question about filling up. I know the Versa comes with 13ish gallons, but when the gas light comes on I am only able to fill up about 10, sometimes 11 if I've been driving with the light on for a little. So I'm assuming that the other 2-3 gallon is for after the gas light comes on? Can anyone confirm this for me?

Also, I know the manual says its okay to use 87 to fill up, but do you still get the full mileage that you would if you put in 89 or 91? I've been putting in 91 and been getting better gas mileage ( i think anyway), but not so much since I do live in California, and traffic here as you know, is the worse.

If anyone can confirm these questions, that'll be great

Thanks.

[Andrews Chalmers]

So I'm assuming that the other 2-3 gallon is for after the gas light comes on? Can anyone confirm this for me?

Also, I know the manual says its okay to use 87 to fill up, but do you still get the full mileage that you would if you put in 89 or 91? I've been putting in 91 and been getting better gas mileage ( i think anyway), but not so much since I do live in California, and traffic here as you know, is the worse.

Gas tank is approx 13 gals - so you do have quite a bit of added security once the light goes on.

Why waste money on 91 if the car manual specifies 87? Higher octane = higher activation energy required for combustion. The Versa's engine simply does not require the higher octane because its compression ratio is not that great.

Using 91 will not get you better gas mileage - it just means your engine is not operating from the fuel it was designed for.

[Vahagn23]

so would you say that its bad to put a higher octane? also everytime I pump and it clicks I can still go for almost 2 gallons more, does it mean its not pumping but the machine shows that it is?

[JoshH]

so would you say that its bad to put a higher octane? also everytime I pump and it clicks I can still go for almost 2 gallons more, does it mean its not pumping but the machine shows that it is?

I knew people that told me they received better mileage with higher octane gas, but it is just a waste of money. Unless your car requires higher octane gas (my dad's car requires 91 octane), you only need to put in 87 octane gas. I don't know if it's "bad" to put in higher octane, but it's definitely a waste of money.

[Mlody]

Why waste money on 91 if the car manual specifies 87? Higher octane = higher activation energy required for combustion. The Versa's engine simply does not require the higher octane because its compression ratio is not that great.

Using 91 will not get you better gas mileage - it just means your engine is not operating from the fuel it was designed for.

not only is this true, but due to the fuel burning slower (due to higher octane value) your engine makes less power. I've also experienced and heard others of saying that their fuel consumption is increased with higher octanes (for the cars that are designed to run on 87 octane fuel) my theory on this is that your engine makes less power so the driver adds more gas to accelerate and you burn more gas.

I've seen results with motorbikes where people would use 104+ octane gas go on a dyno, in their R1s and GSXR 1000s and they would have 15~20 hp less then when they dynoed with fuel that is recommended by the manufacturer (92 or 93 octane or whatever it is).

[Andrews Chalmers]

so would you say that its bad to put a higher octane? also everytime I pump and it clicks I can still go for almost 2 gallons more, does it mean its not pumping but the machine shows that it is?

If there are no benefits - wasting money & resources = bad. Will it damage your engine? I don't know - but why do it if the specs says to use 87?

Don't squeeze more gallons - you risk damaging the fuel vapor venting systems.

[Rockhound]

I thought I'd chime in. On both my previous cars (G20, GA16 B13 Sentra) using higher octane gas resulted in lower fuel mileage. There were times that the Sentra would begin to 'ping' on 87 octane late in its life, so occasionally I'd run 89.

...also everytime I pump and it clicks I can still go for almost 2 gallons more, does it mean its not pumping but the machine shows that it is?

The pump has a valve that determines when your tank is "full". Inevitably, there's always more space for gas after that first 'click' when it shuts off. If you manually keep filling after each 'click' you can fill your tank until it overflows out on the ground. Because of strict environmental guidelines, pumps are also equipped to prevent vapors from escaping into the air - which means some gas might make it's way through the vapor recovery system, even though you paid for it. It's not that it isn't pumping - it's just that your tank is full and cannot accept any more gas.

For the purpose of accurate gas mileage calculations, you'll want to be consistent with your fillups - so just stop filling at the first click each time. The extra space in the gas tank is intended to be there to allow for volume changes due to temperature fluctuation.

[2008nvs]

If your really bent on finding out the millage, fill up at the same pump every time (if posable), I know that it sounds quite a bit over the top, but if you really want to find out what your car is giving you. Every bit of what you do with it needs to remain the same as much as it can. You know, have the same driving style, same pump, same gas, tire pressure ect. ect...

[randyshemin@comcast.]

I believe that the reason the low fuel light comes on at about 10 gallons is that the fuel pump is in the tank, and the fuel in the tank helps keeps it cool. My 01 Sentra SE and previous car (Taurus SHO) exhibited the same "low fuel" light characteristics.

[Rockhound]

I believe that the reason the low fuel light comes on at about 10 gallons is that the fuel pump is in the tank, and the fuel in the tank helps keeps it cool. My 01 Sentra SE and previous car (Taurus SHO) exhibited the same "low fuel" light characteristics.

Well, this is certainly true, but I think the main purpose is just to provide an early warning so you can safely reach a filling station. If the light came on with 1/2 gallon left you wouldn't have much distance to go before running out (15 miles or so max...). With three gallons, you could conceivably drive 75-100 miles to find a gas station.

[keanucosmo]

If your really bent on finding out the millage, fill up at the same pump every time (if posable), I know that it sounds quite a bit over the top, but if you really want to find out what your car is giving you. Every bit of what you do with it needs to remain the same as much as it can. You know, have the same driving style, same pump, same gas, tire pressure ect. ect...

Here's my 2 cents. I agree that topping off until gas is running out is bad, but when you're filling the gas, a lot of air is mixed with the gas much the same way filling a glass with soda or beer has a lot of air from carbonation. If you stopped filling the glass as soon as the "head" reached the rim, you would only have 3/4's of the glass with liquid. If you let the liquid settle down, you can add more, and repeat this process until the liquid is near the top without going over. I wait about 20-30 seconds from the first shut off and then pump at the same rate as before. I then repeat this 2 more times. I usually get about a gallon more after the first cutoff without ever spilling any. Doing this takes out shutoff valve differences for the most part and my mileage seems consistant. I usually get 390-410 miles per tank.

[Ever Victorious]

That's assuming that the pump you're using introduces a lot of air into the tank as you are pumping. I have a couple different stations I use, depending on where I am when I run low on gas.

One is a very carefully monitored, low-speed pump, and it always gets my tank full the first time it kicks off. Never need to top it off.

The other is in a high volume station, and it pumps quite rapidly... I find that if I drive off without topping off, I am quite short on fuel. As keanucosmo said, this is sometimes as much as a full gallon. It's not fuel I'm adding to the filler or overflowing the tank with, it's fuel that didn't make it's way to the tank because the pump thought the tank was full prematurely.