There is a readily measurable difference in the available energy in winter formulation gasolines and summer formulation gasolines.

Similarly gasoline formulations with more ethanol blended in have less energy available.Again this difference is readily measurable.

 

^^ Pretty much what he said.

 

Yes- but NOTHING to do with octane rating- they all fall and rise at the same rate according to the seasons.

Hence the specific usage of the word 'gasoline' in my post above and not 'fuel' or 'E10' or whatever. I'm not silly enough not to know that plums is always just around the corner.

 

Do you go to the "E10" station or something?

No. You go to the "gas" station.

Everyone goes to the "gas" station.

Everyone fills their tank with "gas".

Most people discussing mileage on JF are talking about how much distance they can go on how much liquid gold they purchased from the "gas" station. Whether the mileage might or might not be affected by some percentage of ethanol in the blend is a sub-topic.

So, you might have worded your statement very carefully to be able to state your preferred view of the world in a narrowly circumscribed argument. But, as generally useful information to the majority of JF readers the statement is misleading without qualification. This view is based on the premise that most JF readers view "gasoline" as being whatever the "gasoline" station is selling as "gasoline" without having to do a chemical analysis prior to every fueling stop.

The reality of the current state of affairs in North America is that depending on regional market, consumers either have only ethanol blends available for purchase, or they may be able to purchase increasingly rare non-ethanol blended premium gasoline. To ignore the presence and effect of ethanol is to ignore reality.

 

Actually no, and especially not on a discussion board where a good percentage of members live in or come from the UK, but I'll choose not to play an ongoing game of pedantic one-upmanship.

I think it's pretty obvious what the poster was asking about and equally obvious what the intent of the answer was.

Carry on if you wish.

 

I wish I had Plum's English education.
Seriously, I would love to be erudite.

 

Petrol and forecourt then. But, most UK readers probably made the mental connection without undue stress.

It still holds that petrol/gasoline colloquially refers to the liquid gold dispensed by the vendor although the UK version is somewhat more dear.

 

They pollute our petrol with ethanol

 

I wish they'd serve it on the side like what's known as a boiler maker (beer and a shot of whisky) here in the states. Then I could just drink the alcohol ...

After reading the latest portions of this thread I'm not sure who's using 100% gas for these mileage numbers and who is not. Same issue for imperial gallons.

We do have a few, very few, gas stations here that still serve fuel without ethanol. There's one about 20 miles from the PA-NY border near my remote garages. I'm not exactly sure why it's even legal?

Now here's where the bad part about ethanol comes into play. I have several vintage Italian cars with carbs on them. My Espada has six two barrels on it and I've had to make several changes in jetting from stock circa 1971 specs in order to get it to run decently. Decently but not perfect. The idle jets are richer and a part of the accelerator pump circuit had to have the smallest bleed down orifice available installed. Without these changes the car would stumble when ever you stepped on the throttle.

I may just go there fill up the STR and see what happens. There's definitely less energy per tank and the modern engine management systems should be able to make use of this.

 

Hopefully my post and follow up passed the litmus test for being clear and precise on the two criteria.

I would think that the variation in mileage in switching from 100% gas to E10 or back again would fall into the range of typical scatter as seen from one tank to the next. A 3% change is pretty small.

 

My original comment was to correct the statement "all gasoline has the same energy content".This is not a true statement.The reason is simple--not all gasoline has the same mix of hydrocarbons and we all know that the energy comes from breaking C=C chemical bonds.
Winter gasoline is formulated to evaporate at lower temperatures and this is accomplished by using more lighter hydrocarbons which have less energy content.
This is true whether or not it is E-10 or all gasoline (which,by the way,has not existed since tetra-ethyl lead was introduced to improve octane content!}

As the man said nothing to do with octane rating.

 

Sorry I did not make that clear, my 2.5 Ltr is a petrol engine. Same engine as the V6 3ltr Petrol version, though with a smaller Cylinder Bore size. The Diesel V6 2.7ltr in the S-Type and early XFs, return anything from 35 to 42 mpg (Imperial gallons) on average. The 2.7 Diesel has now been upgraded to 3ltr capacity giving an improve fuel consumption rate on later built XFs.
UK Octane rating is 95 RON* Ordinary Unleaded and 98 RON* Super Unleaded. Leaded 4 Star is 98RON* but not usually available these days and only available at specially licensed outlets..
Regards,
Inver.
*Research Octane Number.

 

I drive 52 miles to work and back every day, with 50% of it at 70 mph and 30% of it at 60 mph the remaning 20% is city. My Miles to Empty usually says I have 404 or so miles when I fill up. I don't thrash the motor, but I'm usually passing more cars then what pass me. I've got 79k miles on her and she runs like a top!! I'm very happy my STR. I'm in Florida which is pretty much at 200 feet above sea level. When we drive on trips to Oralando (6.5 hours away) when I fill up in Orlando, my Miles to Empty says 439.

 

I'll add to the database of real world fuel economy.
Just took a 800 mile round trip where it was 90% hwy and 10% grid lock. 75 - 80mph hwy speed with A/C on and 4 adults. Tire pressure 31 psi all around.

I averaged 28mpg running 92 - 93 octane AKI(whatever premium was available at the fill ups)

 

Last week I picked up my, new to me, '08 4.2l in New Jersey and drove it back to Boston on the highway. Cleared the trip computer at the start and drove at about 70mph with the cruise control set. Over 250 miles it averaged 30.0 mpg!

My '05 X-Type that I drove down to New Jersey to trade in, over the exact same route in the opposite direction, only got 27.0 mpg.
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Jaguar: Grace, Pace, and Space - Sir William Lyons

 

The engine and ZF autobox are quite a good match

And which one do you like most?

 

>And which one do you like most?

The one with 300hp...
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Jaguar: Grace, Pace, and Space - Sir William Lyons

 

Yesss!