Yeah, moisture has always been the problem. I remember decades ago, even when we still had "real" gasoline, old Gramps saying that cars (or trucks, or tractors, or lawnmowers) should be stored with the gas tank full so condensation wouldn't rust the inside of the tank.

One reason E10 isn't much of a problem on newer cars is that the fuel tanks/systems are so well sealed. Air and moisture can't get in.

Cheers
DD



Usage wasn't wide spread back then and the term "E10" wasn't used. The text in my manual is something like ".....fuel with up to 10% alcohol content can be safely used....".

Cheers
DD

 

My last pickup, a 1997 I bought new, lasted 20 years and almost 400,000 miles without a bit of engine/transmission trouble.
I sent it to the scrap yard because the dreaded tin worm had the fenders and doors flapping. Brake lines rusting through annd the frame getting very questionable. and it still ran like a top.
I’d used it to build my house, ( hauling 500,000 bd feet of hardwood Timbers and. Lumber home, 22,000 pounds of granite., enough SIP’s and ICF’s. , windows (105) doors (22) cabinets (28) nails Lag Bolts , shakes plumbing wiring, trees bushes landscape material etc etc etc
Hauled my race car all over the country, put my 28 ft cruiser in and out of the lake, probably hauled home more than 10 Jaguars and another 50 V12 engines.
Plus Monday through Friday, worked as a traveling salesman out of it.
Always used E10.
By the way. When using more than 15% ethanol. The car needs to be tuned for it. Mixture richer and timing advanced. That’s what modern ECU’s do for you. ( if you’ve got a sensor to detect how much ethanol is going through your fuel line)

 

things won’t change dramatically. All gasoline ( not just ethanol blends) all gas has some water in it. The holding tanks at the refineries have to be vented to let the fuel out or it will create a vacuum powerful enough to collapse even those giant tanks.
Vents are where moisture in the form of humidity gets into the gas.
Same with the tanker hauling it to the gas station, the gas station itself, and your own car.
Older cars used to have a glass bowl to collect the water. Then they found out that a little water smooths out the combustion process and got rid of those fire hazards.

 

One remark about how it helps some farmers.
There are very few farmers left with smallish plots. 40-80 even 100 acre farms are no longer viable.
It’s corporate farmers who collect the proceeds of the GOVERNMENTS largess. Yet they all live by the market. Too much corn is planted and even with subsidies. It’s very hard to make a living on less than 1000 plus acres. The price of everything seed fertilizer, insecticide, equipment fuel Is always going up. And weather is a big gamble.

 

I grew up on a working farm on the east coast. Know all about that.
My kin still run a hundred acre piece there, it's more a habit and labor of love than anything though.
My Grandmother who was a farming wife all her life told me not to say anything if I didn't
have something good to say so I'm going to not get into my opinions any further about
farming politics other than to say it's not okay the way it's been going.

 

I've rarely had a vehicle with less than 200K, many over 400. The XJS is still young at 250K.
I'm glad you've had good luck with E10 but Ford says what they said, and my experience and observation has
been as I related.

I mentioned the eth content sensor back a little bit, part of the problem running aggressive tunes on E85 on the street is you don't know if you're getting e85 or e70 or e50
or what, so your engine management needs to be able to account for that. This is accomplished by a sensor, which is pretty much the same concept as flex fuel vehicles
use, that will tell the ECU how much ethanol is in the fuel and adjust the tune to suit. It's a fair bit of work to get it all worked out safely on a custom tune but the
performance available vs premium straight gasoline is impressive.

 

What I was saying is that as poor as the fuel mileage is on a v12 Jaguar, it would not be difficult to drive it a relatively small amount
and use enough fuel to keep it fresh in the tank.

 

Well let me throw some more fuel on the fire ....

Ethanol is aggressive, bad on the plumbing for old cars but not forbidden - even the Jaguar workshop manual says up to 10% is OK and doesn't really say the consequences - though the comments that increased Octane requires changes to tuning are true - however in the way measured in the UK the XJS is not supposed to be run on anything less than 98 octane - good ol 4 start to brits or 93 octane to those in the US, especially the high compression V12's, so anyone running a V12 in the UK on 95 E10 octane cease and decist. Ethanol also attracts moisture which results in rust and corrosion but it takes time for this to happen, ethanol also attacks classic car plumbing - including those parts hidden from view - above the rear subframe for instance.

Methanol is forbidden at more than 3% by volume.

Oxidation is the other topic not yet covered and that is what is responsible for the black sludge as fuel oxidises and breaks down. I've read a couple of papers on this oxidation process and fuel storage and it seems clear that the shelf life of todays fuels is at best 6 months in anaeribic O2 free storage, as little as a month in a fuel tank, once it starts to darken / change colour it is time to get rid, not only is it transitioning into that horrid black goop that I've had so much fun with but it also produces a whole raft of other nastiness including acids - which is a whole different challenge in the UK as it is not the easiest substance to dispose of. The brown varnish is from a similar process but is mostly what is left when all the liquid has evaporated away. Some of the degredation / instability is caused by the catalysts used to remove sulphur. The process can be inhibited by regular topping up with new fuel which replaces some of the stability. One solution to prolonging the life could be simply to keep the tank full and limit its ability to breath due to temperature changes, changing fuel hoses to modern low permeability hoses is also advised - I currently have a box full of Gates Barricade hoses of various diameters.

There's a really cool book too if anyone is interested by Paul Ireland called Classic Engines, Modern Fuel: The Problems, the Solutions

And whilst the higher octanes will burn be aware that not changing the timing to suit them will increase underbonnet temperatures as they're still burning quite hard when exhausted, may want to consider a hotter plug too - because the higher the octane is the more reluctant to ignite it is -

 

I wonder how 'shelf life' is being defined.

The moment the fuel begins to slightly degrade? Or the moment it becomes obviously unsuitable for use?

IME, it couldn't be the latter. FWIW, my Series III V12 (which is now relegated to 3rd car status) has had the same E10 in the tanks for 3-4 months now. I just drove it last week and didn't sense anything amiss. Easy starting, smooth running, no smoke.

[shrug]

Again, variables?

Cheers
DD

 

I think it is measured in terms that are more aimed at retailing the stuff - here's one source, there's a lot going on in that dino juice ... AntiOxidation of Fuel, Fuel Storage - not white paper but covers the causes of degredation

I was reading another about the black goop and what it is but can't find it again - looking - will post when found

And yes the variables are many.

 

This is one I found at Mansfield Energy ... notice that water does play a role .. I will find that paper .... been a day or three since I read it.

What causes sludge?
Sludge build up can be caused by many factors, but is more likely to form when water is found in fuel as different bacteria can grow and cause contamination. These microorganisms once formed will sink to the bottom of a fuel tank and latch on to dirt and other small particles forming sludge. A few common causes of sludge build up include:

Oxidation of Fuel: Over time, fuel can undergo oxidation, a chemical reaction with oxygen that produces undesirable compounds, contributing to sludge formation.

Microbial Contamination: Water accumulation at the bottom of fuel tanks provides a conducive environment for the growth of microorganisms. These microbes feed on the fuel, multiplying and producing biomass that contributes to sludge.

Water Contamination: Water can enter fuel tanks through condensation, leaks, or during filling. It can lead to the separation of water-soluble components from the fuel, contributing to sludge.

 

Variables for sure. Fuel formulations vary regionally and from one time of year to another I've always read, may have something to do with it.
I've worked in the automotive salvage industry for decades (and crawled a hell of a lot of junkyards as a kid).
We get cars from auction that have been sitting for a year give or take and the fuel in them frequently won't
run well and looks and smells "bad", and the fuel pumps are almost always dead from sitting in it. We've also pulled cars that have been
stored inside since the 80's and the fuel was still useable. Anecdotal for sure, but it's been a consistent
experience for a long time and seems to be shared among colleagues.

If it's any consolation diesel isn't any better in the US, likely worse for older applications.

 

Worked weekends in a breakers yard as a teen in the 70's, the full timers used to divy up the fuel drained from cars, so I could add to that anecdotal evidence.

Diesel here is the absolute pits - ask any boater about the organics in diesel fuel thanks to dilution with 'bio diesel' ...

 

They still do that at a lot of yards, it's very modern now mostly, fluids carefully removed, etc at newer salvage places.
I worked at once that just let the staff fill up, they had a storage tank they had rigged with a number of pretty heavy duty
filters and a standard analog filling station pump. That was a high volume yard so not much we got sat for long, but I
still avoided it. The first old mom and pop yard I worked at took scrap cars by weight across the scales, he had an
enormous steel vessel with a large metal spike in the middle, they would pick the car up with the loader and
lower is down on the spike to pierce the fuel tank and drain it then rip it apart and crush it. Every so often
the old man would drive that large container around the yard on his loader forks with a couple of valves open draining
the fuel out to kill the grass. I wouldn't drink the water within ten miles of that place....


I've been running additives in my old diesels for decades, since they pulled the sulfur out of it.
Who knows what else. It is certainly not what it was, I've got the same motors from 30 years ago
and none of them run as well or get as good a mileage regardless of state of wear or tune.
It's an annoyance.

 

Found it - the black goop is the same stuff that plagues diesel and is basically the bi product of stuff that consumes hydrocarbons Microbial Contamination

 

yes moisture has always been in gasoline.
If you go back far enough gas pumps had a glass display tank to show how much water was in the gas. (100 years ago)
Later in the 30’s & 40’s they had glass bowls under the hood so when enough water would show you could drain it out.
Then they found that a little water helped the engine run smoother. So the fire hazard of glass bowl was done away with.

All cars have to be vented to air or gas wouldn’t come out of the tank. Now days it’s through charcoal canisters but that keeps gas in not humidity out. Besides gasoline gets water in it plenty of ways between the refinery’s big tanks and your car getting it pumped in. Every gas station operator has a water detector on the tip of the stick they use to measure how much gas is in each tank.

 

Diesels of the sort I associate with have water seperators, usually with a drain.
The black goo has been a thing for longer than I've been around them, never had any trouble with it in cars or farm equipment myself but it happens.

More to the point, a lot of these cars get few miles on them for whatever reason and spend a lot of time sitting around.
Anything that makes life easier on the fuel system, such as not using ethanol mixed fuels, is probably a good bet.
If you run a tank of fuel out of them monthly-ish or more often it's probably not that big a deal other than the possible decrease in fuel mileage.
But every now and then there's some tragic example of things gone wrong pops up and nobody really knows why. You pays your money
and takes your chances these days. IMO it's not a painting or a statue, drive the car as was intended, often.

 

Very difficult to drive when they look like the image below, and unless you have owned the car from new can't possibly know it's history - service histories aren't woirth a damn. Mine was laid up in a barn - yes really - since 2003 until I aquired it in late 2019, I ran it for 6 months after a short refurb that included flushing the fuel system then committed to a larger refurb - that has turned into where it is currently and has been for 3 years. I cannot be sure when the 'rot' set in with the fuel but there's no way it ran with what I found in the swirl pot - except it did so I attributre it to the last three years, it is easy to be a genius in hindsight.

You can't drive something with no wheels. Had I known what to expect i.e. on the ramps for 3 years I would have drained the whole system before starting. I do wonder how many of the issues faced by members here are because there are systems in sub optimal condition from the day they got the car - not enough to stop it running but enough to give it a personality.

Grant's to do list in the stickies should be considered a mandatory to do list for any of these cars unless the origins / source are known.



Actually a lot further on than this but they're hard to drive in this condition. My rebuilt diff / shafts and hubs should be here in the next few days so I should be able to get a fully rebuilt rear subframe back under the car before the 11th Aug - there I've jinxed myself..

 

So true! As someone on here had as his byline a quotation from Carol Shelby: words to the effect that "his cars are made to have the wheels driven off them, not to be museum pieces."

"Thou shalt not bow down and worship graven images"! Though this following sentence is rarely translated from the Hebrew it goes on to say "however in the case of the Jaguar XJS this sin is understandable and will be forgiven".

 

Agreed.

And to some extent...a rather large extent, IMO....it doesn't really matter. These are hobby cars now. A person buying a 5 or 10 year old XJS wouldn't reasonably expect needing a major fuel system overhaul. But these cars are now 25-30-40 years old. We're in an entirely different realm of ownership.

Even cars with a three-inch-thick portfolio of service records very often have been neglected in certain respects....with now-well-known problem areas never being tended to. That's not a condemnation of anyone or anything. After all, there's nothing in the "Recommended Service Schedule" mentioning replacing fuel hoses every 10 years, or removing the fuel tank for cleaning at 20 years, or adding a redundant ground to the instrument cluster at 25 years.

And this realm is not unique to Jaguar. It could just as easily be a 35 year old Camaro, or BMW, Subaru.

Cheers
DD