I filled up my car and I have a habit of resetting my mileage tracker (next to odometer) to see how many miles I get out of a full tank.
I've noticed that I get much less gas than usual for the same number of bars.
What can I do to make this more concrete? Has anyone else noticed this?
Now is right about the time that refineries and gas stations switch from winter blend to summer blend, so maybe there's something to that.
https://carbuzz.com/feds-fight-gas-prices-easing-ethanol-res...
Of course tune up.
Have you changed gas stations / brands recently?
>I've noticed that I get much less gas than usual for the same number of bars.
I'm having a hard time parsing what this means.
>- gas smells less like gas
Is it possible for a person to smell the difference between octanes? The higher octane fuels have lower volatiles, so that might affect the smell.
You shouldn’t be noticing more than a 7.5% drop between E0 and E15 gas, which would be a pretty hard swing in gas composition. What % do your figures show?
Or not.
Ethanol has an Octane rating of 114%, meaning that you can run your engine with less fuel in the fuel/gas mixture, if your engine, pipes, fuel pump and rubber hoses are made for that.
Ethanol is pretty awesome in terms of HP output, but you have to reprogram the maps in the ECU to correctly use it. The timings of "how fast" Ethanol explodes inside your engine cylinders is also faster, meaning if you don't remap your ECU there's chances of backfire because the valves don't close fast enough. That means if you don't have a V-Tec or similarly digitally controlled valve steering you have to also modify your camshaft.
Source: Rebuild 3 cars and their engines to be fueled with Ethanol because I live near a race track with cheap access to Ethanol.
Edit: some gas stations in the past were using shitty additives to boost the ethanol mixture with toluols and methyl ethylene variants, so could also be that. They're really bad for your engine block. Like, reeeeally bad because their mixture is very unpredictable and varies too much for a proper ethanol ECU map.
There is quite a bit more expansion & contraction of hydrocarbons with temperature than many peoople expect.
Fuels containing a higher amount of Aromatic class hydrocarbons, (or just lesser "light" hydrocarbons) will have a higher density (lb/gal) compared to fuels having lower amounts of the heavier molecules.
Also the aromatics bring with them higher antiknock ratings which can also be better for efficiency in a number of different engines.
When acceptable octane rating is achieved by ethanol content instead, it works good too, but fuel efficiency is reduced chemically because alcohol does not consist of only carbon & hydrogen, alcohol molecules also contain oxygen which provides bulk but not energy, so alcohols can be considered to already be "partially oxidized hydrocarbons" to begin with. It's really the oxidation process of the burning fuel that provides the energy, and alcohols just have less to give than hydrocarbons.
Miles per gallon is the conventionally understandable measurement units, and even fuel injectors meter the fuel in by volume, but actual energy obtained and resulting engine efficiency depends on performance per weight of fuel, not exactly per gallon directly.
During changing seasons I like to feel the metal part of the gas nozzle for temperature during dispensing. One of the worst times is when a tank trailer has been sitting in the sun a while before delivery, and it's 95 Fahrenheit when it's not even that hot outside. I like it much better when a trailer comes from northern locations where the fuel is less than 60 degrees, then I buy more but don't fill it up. It's nice when it is colder fuel to purchase and if it's a hot summer once the gas warms up to ambient conditions you end up with more gallons than you pumped, but if you are not careful the gas tank will overflow "autonomously" if you fill it too much with cold fuel when it warms up like that :0
There are a number of other factors too, but this one is often overlooked.