I just filled up for the 2nd time in my new Clubbie.

The OBC said I had 28miles left and the "gauge" had one red.... thingie...

I read my owners manual, and it says 13.2 gallon tank...

lookie here:



13.7? wtf... really? I was running on negative fuel? I HAS SOLVED ENERGY CRISIS!

seriously... what happened here? Should I be calling the VT trades and measures commission, talk to the gas station, or is my owners manual just wrong? I filled to one click, as I know the wrongness on overfilling.

 

Most cars have a 1 gallon (more or less) reserve, and remember the filler neck....that and rhe plastic tank flexes and bulges a bit....

 

so the 13.2 is a lie? why publish it everywhere that is how much it is? plus I probably had a 1/2 gallon anyways left.

i dunno..... something smells fishy

 

The following explanation is based on my historically bad memory of a conglomeration of past experiences and conversations. The opinions below probably have some kernel of truth to them but the details are most likely flawed on some level. Please acquire further help from experts before listening to anything I say.

Gas expands and contracts with changes in temp and gas fumes do it even more so. So I'm pretty sure all fuel tanks have to be made with extra room for fuel to expand into as well as overflow valves or something. So the tank is prob built to hold 13.2 gallons with the rest in reserve for expansion and safety.

When you got 13.7 in did you stop the first time the pump stopped or did you go for a couple more clicks? That could certainly account for the extra fuel pumped. The pumps "full sensor" or what ever could also be malfunctioning. I have heard however that this is a bad practice as some of the fuel gets wasted when it expands out a safety valve or out the filler tube. Anyway would you really need .5 gallons more? Its bad to constantly run almost out of gas anyway because you can get more sediment into your fuel pump and filter. I try to refill at 1/4 tank its a good habit and lowers your chances of getting stranded.

 

I have an '07 MCS and my fillups when I'm really low on gas are always more than the stated tank capacity.

 

Fuel does expand and contract as it wishes so that translates to variable volume. What you are missing here along with one other poster is the real threat of expensive maintenance when you run out. Running your tank to near dry is asking for expensive trouble. A cavatating and overheating fuel pump will soon need to be replaced. Mine NEVER gets below 1/4 tank.

 

shipjumper: I'm surprised that no one's pointed out that you saved 96 cents by going with Plus grade rather than Premium. More importantly, did your fuel mileage on your second fill beat the 46 mpg from your first tankful?

 

Nothing fishy about it. Every car I've ever owned holds mire than the published size of the tank. And I should know... I routinely drive until my once shows less than 10 miles until empty.

 

Gas pumps have been known to give you a little less than what they say they are giving you - that's why they get checked by the state weights and measures department every so often and get a seal on the tank - at least that is how they used to do it back when I worked in a gas station. If you feel you are being charged for gas you are not getting than you can make a call to your your state’s Division of Measurement Standards and have the station checked.

 

Always buy gas when the fay is at its coldest temp.

Supposedly.

 

I was going to point this out if you didn't.

 

Lots of people have filled with more than 14.0 gallons, some in the 14.5 gallon range, myself included. Just like the speedo reading fast, the number printed in the manual is some form of protection from ourselves.

 

Your fuel tank will hold a greater weight of fuel when that fuel is cold. And it's the weight of fuel that counts, not volume (why do you think injectors are rated in pounds per hour?). In effect, you get more potential energy for your money when the gas is cold.

However, the fuel at gas stations is stored in huge tanks, buried underground. The large volume alone means that the fuel's temperature would change very little with the daily rise and fall of air temperature. And the fact that it's stored underground means that the fuel will be dispensed at the same temperature regardless of the time of day.

What's more likely to happen is that you wait until 2am to fill-up so that the air temperature is at its coolest. Then you go home and park your car which sits in the rising temperatures with a full tank. The gas in the tank expands as the day gets hotter, but has nowhere to go. It eventually finds its way out through a seal or the EVAP system, and your hard-earned dollars wind up as a puddle on the ground.

 

Didn't it also say something about running at least 91 octane?

 

Most I've put in is 14.782 gal, that was when we didn't notice it was low at the track and came off with the computer reading 1 mile, which then clicked down to zero.

It could be worse, you could have an early R56 Cooper. The manual said they had a 10.6 gal tank, but they actually put the 13.6 gal one in instead. (The 10.6 gal tank is found on European models.)

 

I believe the OP is driving a "justa" Clubman and not an "S". I know the owners manual recommends 91 octane for all Coopers but I suspect lots of justa owners are running 89 octane instead.
Not trying to start another octane war but it seems a little illogical to recommend the same gas grade for both boosted and non-boosted engines.

 

original post stated I stopped at first click. I have worked in the auto industry for the past 15 years in every capicity, currently in a parts dept of a ford dealership, and have seen my fair share of people that I have PHYSICALLY sen hours earlier doing the CLICK CLICK CLICK CLICK at the pumps in later for a $800 charcoal canister.

I dont need the .5 gallon more. I was holding the pump handle looking at the paint on the roof dreaming of a carbonfiber wrap when it clicked off and I stared at the pump with my face.

I know... kinda durr...

unfortunately, no, I did the math and I got 39 this week, but I did lots of shenanigans and back roads... mountain passes on my ride home

I have had the opposite experience, my past 4 cars have been dead on with the OBC. 3 SAABS and a subaru.

Says "Recommended", not "required" like my past turbo cars.

yep. Its not 13:1 compression, turbo, 8,000,000 rpm.

I just wish we did not have that crappy E10 in all our fuels.

 

Off topic but this would make a great sig tagline

 

i liked it too... sorta like a mythbusters opening.

 

Fuel density is lower on a warm day, and it also decreases with altitude. (This means you get more volume per pound of fuel.) So I'm surmising that on a warm summer day on a Vermont mountaintop, this is the case. Now I have no idea how the fuel pumps are calibrated or whether they measure weight and calculate volume from ambient conditions, but if so, that could be part of the explanation.

 

Best, most useful line in this whole thread!!
Got my day off to a smile.
I bet 90% of cars can get more fuel in the tank than the rated capivity...about 5-10% by volume is left empty for expansion too....
But to the op...
FUEL COOLS THE PUMP...add more fuel befor you get to less than a few gallons left, or you might be buying 2 very $$ fuel pumps....pretty easy to void the warrenty on tgem due to abuse!!

 

Man, if Ulta 93 was an option here that's what Molly would be drinking!!

On a side note...I had a Fuel Station Attendant Friday Night that could not give me a receipt, the pump did not spit one out, in order to get one she needed to know, "how much?". Anyway, I was thinking to my self..."I drive a MINI...I don't care how many gallons or $$ I've put in the car I just want to get back in and MOTOR!!" Needless to say I left a bit angry, but oh well, that quickly changed as we happily tooled down the road!!

BTW...Molly gets a drink every Friday Night and usually 6 or 7 Candy Corns are still lit!!

Another side not...you may want to sign up on www.fuelly.com.

 

I would LOOOOOVE to see one ... just one warranty claim that was denied because the owner ran out of gas.

People run out of gas... thats a mistake, not abuse.

Every car I have owned I have owned for over 150,000 miles and have run the tanks down to nothing, never ran out mind you, I have never called AAA for gas. I have also never replaced a fuel pump.

On the flip side of the coin, my wife drove her Toyota Echo for 180,000 miles and ALWAYS ran out of gas.. but that pump died at 160k for the first time.

In my personal life experience I have not seen this happen, nor had it happen to the thousands of customers I have dealt with on a day to day basis.

 

Could be it has changed with the new motors, but my understanding was the normally aspirated engine runs at a higher compression ratio than the turbo engine when not boosted.

 

it does, but nothing that warrants a required or permanent use of 91+ octane. Even modern turbo engines can use 87 sparingly, the volitility sensors in the tanks and the knock sensors along with the 32bit processors can pull timing and not allow damage to the engine.