Long Distance MPG

[elm70]

It's not so much the (incremental) weight of the extra fuel you might add, but the age of it that matters.
You don't want it going stale so you want to keep it fresh by putting less in.

The main question is :

Does the fuel really age while sitting in the car tank ?

I know for fact that keeping the petrol fuel into a 5L plastic portable tank does not cause any ageing of the fuel.
While keeping the fuel in a non sealed container, it will cause to lose many important properties already after few days/weeks of improper storage

The other question is:
What is the side effect of using a "aged" fuel in a modern engine ?

I know my 2T dirt bikes take longer time to start using "aged" fuel, but they will eventually start and run, just with limited power
Similar does my tractor which is used only in summer, but it has better fuel sealing compared to the totally exposed aeration from the dirt bike tanks

PS: Personally I have no issue on living the same fuel in my PHEV for up to 6 months .. and personally I feel better to keep the tank full then half empty, since it has less air in the tank which can cause to "age" the fuel.

 

[twosout]

I don’t know how quickly or badly petrol ages but have noticed a difference in smell and difficulty starting the mower when using fuel left from the previous season.
If you have noticed a lack of power, which would appear possible, I’d have thought it better to keep fuel fresh and get better mpg than let it deteriorate and suffer reduced performance.
It won’t be an issue if you regularly travel beyond EV range or if you make a long journey every so often (when it’s probably best to take the tank as low as possible before refuelling).
I think it’s prudent to put what you expect to use into the tank. Keeping the tank full does not seem very practical but brimming it when you refill would be fine if you foresee it being used in the next couple of months.

 

[maby]

It's not so much the (incremental) weight of the extra fuel you might add, but the age of it that matters.
You don't want it going stale so you want to keep it fresh by putting less in.

The main question is :

Does the fuel really age while sitting in the car tank ?

I know for fact that keeping the petrol fuel into a 5L plastic portable tank does not cause any ageing of the fuel.
While keeping the fuel in a non sealed container, it will cause to lose many important properties already after few days/weeks of improper storage

The other question is:
What is the side effect of using a "aged" fuel in a modern engine ?

I know my 2T dirt bikes take longer time to start using "aged" fuel, but they will eventually start and run, just with limited power
Similar does my tractor which is used only in summer, but it has better fuel sealing compared to the totally exposed aeration from the dirt bike tanks

PS: Personally I have no issue on living the same fuel in my PHEV for up to 6 months .. and personally I feel better to keep the tank full then half empty, since it has less air in the tank which can cause to "age" the fuel.

Fuel certainly does age - I think the extent to which you notice it depends on the type of device that you are burning it in. It is a big problem for boat outboards - we face it every spring. As petrol ages, some of the heavier fractions in the fuel tend to separate out and become sticky. Engines like outboard motors and chainsaws usually have conventional old fashioned carburettors with tiny jets - often little more than the thickness of a hair - and they simply block with the sticky gummy deposits that separate out from the petrol. It generally matters less on a larger engine - those that have a carburettor will have larger jets that don't block so easily and more modern fuel injected engines have a pump that is pushing the fuel through.

I don't think that the sealing of the tank makes a lot of difference where petrol is concerned. It is a big consideration for diesel which will develop "diesel bug" - a biological growth with micro-organisms that are actually digesting the fuel. Diesel powered boats which are not used over the winter can suffer badly resulting in the need to completely strip and clean the fuel system. We add a biocide to the tank every time we fill up in order to control that. I've never heard of "petrol bug" - I don't think there are any little critters out there that can digest unleaded.

 

[Tai626]

Here in California, there is talk about “energy density” variation during a hot day. 1 ga. of cold fuel early in the morning will provide more energy than 1 ga. in the mid afternoon. Probably it is the reason MMNA give us a different tank (not sure even it is different...)? I have a picture that I put 13.5 ga. (51L). That or pump is rigged...It took a while, but is doable. I was on my way home from Las Vegas so I am sure that most of fuel would be burnt right away.

Just for your reference: round trip - 508miles, using 21 ga. fuel and full battery. Approximately 23 mpg (10L per 100km). From 300 feet (100m) Above sea level up to 4000 feet (1300m) and back.
80mph (130kph) most of time, even uphill. 100mph (160kph) sporadically.

I am wondering how a V6 Outlander will do at this speed...

Tai

 

[STS134]

It's not so much the (incremental) weight of the extra fuel you might add, but the age of it that matters.
You don't want it going stale so you want to keep it fresh by putting less in.

The main question is :

Does the fuel really age while sitting in the car tank ?

Instead of just speculating, if you store fuel in your tank for months, why don't you siphon some out and have it analyzed?

People were speculating that oil changes don't have to be done as often as with ICE only cars because in PHEVs, the ICE doesn't come on as often. I showed that to be false; the problem is very high fuel dilution: http://www.myoutlanderphev.com/forum/viewtopic.php?f=10&t=2110&hilit=Blackstone&start=10

I would never be able to provide a sample for this purpose, because I go through a full, topped-off tank of fuel every 3-4 weeks if not more often.

 

[maby]

...

I would never be able to provide a sample for this purpose, because I go through a full, topped-off tank of fuel every 3-4 weeks if not more often.

I get through at least one tank per week, so not a problem here either!

 

[STS134]

There are a few points to note here, namely that petrol pumps here do not have the vapour recovery cover you talk about, and a brief look online shows that fuel pump nozzles in North America are significantly different to ours.

I tried this 'topping off' process when I filled up this afternoon.

My normal fill up method is to push the nozzle right in, pull the handle to maximum until it clicks off, I then count to 10 and pull the handle again until it clicks. Then I withdraw the nozzle until the large ring is resting on the outer edge of the filler tube and pull hard enough to start the pump, but keep this minimum flow going until the fuel clicks off. Using this method all the time, once in 87,000 miles, at an average of 34mpg I have managed to get 43l in the 45l tank.

I have used this method, at every fill up for the last 1.2million miles with petrol and diesel without incident. The only time it varies is in the summer when I know the car will be parked in the full sun almost straight away. To allow for fuel expansion I only go to the second click.

Today, the pertol station was relatively quiet, so I decided after my usual process was complete to wait 30 seconds, then hold the pump right at the very entrance of the filler neck and squeeze very gently. Over the next 3 minutes I got just under a litre of extra petrol in. For the last minute there was standing fuel in the thread that the cap locks in to and it didn't drop away at all.

With all respect to our American cousins, there is no way that amount of extra fuel can be forced into a UK (and I suspect European) spec car. I agree that my personal preference would be for a larger tank (by an extra 20l), but I fully understand that I am not really the kind of driver this car is aimed at and the reasons why this isn't possible.

Check this out. I got the fuel tank down to 25 miles of indicated range on gasoline alone (battery was empty so it was also 25 miles of total range). I don't believe it was quite at the point where the computer would have auto disabled Save mode, but it was close. PHEV Watchdog was showing 1.0 US gallon of fuel remaining. I then topped off the tank.

I got about same amount of fuel in that I was able to get in last time. If I were to drive it until the computer auto disables Save mode, I'd probably be able to get an extra 0.25 or so US gallons in. If I literally ran it dry, probably an extra gallon or so. But as it stands, I got 13.472 US gallons or 51L into the tank, while not even having used up every last drop.

 

[VillageIdiotDan]

I'd need a loan over here to buy 51l of fuel!

Nice work though, with no mountains left to climb this is our Everest!

 

[Steel188]

Would someone else in the UK try this method please?

Having cut my mileage by a 1/3 to ‘only’ 30,000 a year I’m obviously no good at this filling up lark! I have been known to go through 3 tanks of fuel a day and never use less than 3 a week, and I have never come close to 45 litres let alone more than 50.

I can only think that our different nozzle designs mean a change of tank neck.

Please try it and report back, my incompetence is bugging me

 

[Tai626]

Still from US, Here is my picture. Just a drop more...Las Vegas gas price. I did have 5miles of batteries range so I was not afraid to dried up the fuel. Unnecessary risk, someone may say.

 

[STS134]

Still from US, Here is my picture. Just a drop more...Las Vegas gas price. I did have 5miles of batteries range so I was not afraid to dried up the fuel. Unnecessary risk, someone may say.

The times I ran the fuel all the way down until the computer automatically cancels Save mode (but it will still use the ICE if you floor it), I was able to get around 13.8-14.1 gallons in.

 

[jdsx]

Hmm interesting. I've only run it down to where the overall range remaining goes to ---- a couple of times (which mine does once it gets down below about 40 miles), and the most I've managed to fill up is 38.5 litres. (This means as much fuel as I could put in after the pump clicked off two or three times... life's too short etc....) I checked Fuelly (admittedly a while ago) and of the thousands of fill-ups on there, only a tiny number were above 40 litres. Maybe they made the US fuel tank slightly bigger.... :shock:

 

[Steel188]

Google is our friend.

The US brochure states that the tank capacity is 11.3 US gallons which is 42.775 litres. There has to be another explanation as to how STS134 can get more than 50 litres to in his car.

As I asked earlier, can someone else n the UK try this ‘topping off’ process and see how much you can get in, because I am with all the other respondents from this side of the pond. 38 - 40 litres is normal and 42 - 43 if you Car has been screaming at you for 50 miles to fill up.

 

[twosout]

Most I have put in mine was 38 litres. Might have been able to squeeze another litre but did not bother. Range at the time was ----.

 

[STS134]

Google is our friend.

The US brochure states that the tank capacity is 11.3 US gallons which is 42.775 litres. There has to be another explanation as to how STS134 can get more than 50 litres to in his car.

As I asked earlier, can someone else n the UK try this ‘topping off’ process and see how much you can get in, because I am with all the other respondents from this side of the pond. 38 - 40 litres is normal and 42 - 43 if you Car has been screaming at you for 50 miles to fill up.

Well, the simple explanation is that the extra space that gets filled when you top off the tank isn't counted as part of the capacity. The pump actually clicked off automatically at 9.5-10.0 gallons, and I filled it to 13.472 by topping off. As I said, it drains slower and slower as you keep adding fuel but if you are patient you can get a lot more fuel in there. I fill until the level of the liquid is just below the spout, such that the hole that the nozzle fits into is under the liquid level AND it drains at less than 1 cm/minute. If I can look at the liquid level in the spout for 3-5 seconds and it's still visibly draining, then more fuel goes in.

 

[Tai626]

Are we filling the EVAP system???!!! Attached a schematic picture, not PHEV.

https://www.moparmagazine.com/2018/07/too-much-in-the-tank/

Tai

 

[STS134]

Are we filling the EVAP system???!!! Attached a schematic picture, not PHEV.

https://www.moparmagazine.com/2018/07/too-much-in-the-tank/

Tai

I'd imagine that parts of the EVAP system (in particular, the parts that connect to the tank, up until the level of the spout) do fill with fuel. I would hope that the engineers who built this thing weren't stupid enough to put that charcoal filter or anything else that's critical below the level of the spout. I never had any issues with my old car and I topped off the tank in the same manner for years. Also, if you fill the tank from a large gas can, you're going to essentially be doing exactly the same thing.

 

[cornclose]

Most I have put in mine was 38 litres. Might have been able to squeeze another litre but did not bother. Range at the time was ----.

Similar here, 2019 4HS (UK spec). 39 litres exactly (after pulling the trigger several times, with pauses in between..) and my range had been showing '---' for several miles, which spooked me since I had only just got the car (dealer supplied it practically empty and with no battery charge!!). It had been showing 50 miles overall range for a (very) short period of time - which lulled me into a sense of security as I assumed that was accurate. Since it then changed to '---' and I had absolutely no idea what my real range was, and with a flat battery, I decided to fill up.

39 litres was what I got in, and I've never got any more in since.

Incidentally, my 2019 4HS is the stand out best car for accurately predicting range on remaining fuel, both electric and total. It's such as shame that 50 miles rapidly turns to --- as then you have no clue. In reality, from what I have seen so far, that remaining 50 miles is probably accurate but unless you're keeping track of distance travelled since that point, you're brave to continue for long ...!

 

[cornclose]

A few notes from the UK 2019 manual;

* Fuel tank capacity: 45 litres

* When the gun stops automatically,
do not fill with fuel any more.

* When the fuel is reduced to approximately 7
litres, the information screen switches to the
interrupt display of the fuel remaining warning
display, and the “ ” mark (B) on the fuel
remaining display flashes slowly (approximately
once per second).

* If the remaining fuel level is reduced further,
the information screen switches to the fuel remaining
warning display and the “ ” mark
(B) on the fuel remaining display flashes
quickly (approximately twice per second).

The above tally with the amount of fuel I have managed to put in the tank (39 litres). The warning comes on when 7 litres remain, so my 39+7 = 46 litres, which makes sense on a 45 litre tank.

 

[twosout]

Sounds very familiar, mine is MY19, too.
7litres seems a large margin in a 45litre tank. I think my other vehicle stops estimating range at about 5litres (in an 80litre tank).
I suppose that they feel that people may take it to the last drop, given encouragement.
I tend to add 20 litres once below the half mark. Only go for full when a long journey is anticipated.