Ask HN: Does anyone else notice that gas runs out faster than usual

- gas smells less like gas - not getting as much mileage as usual

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?

Do you always fill up at the same station or same brand? Maybe they are adulterating the fuel (higher ethanol content, etc.). You can get test kits for ethanol content. Maybe your vehicle needs a tune-up? They could also be fiddling with the dispensing measurement, saying that you put in 12 gallons, when it was really only 11. Harder to check than you might think, since some operators were adjusting things to come out correct at like 5 gallons, or whatever the local authority was using to audit things. Also, internal combustion vehicles get less efficient as they age/wear.

>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.

Unless you find a fast station that sells ethanol free gasoline (and you'll know because it costs more), gasoline is cut with up to 10% ethanol. 1 gallon of ethanol is equivalent to 2/3 a gallon of good old gasoline. So to keep things simple, if you buy 10 gallons of gasoline @ 20 mpg is 200 miles. But 10 gallons of gasoline with 10% ethanol filler is really 9.6 gallons, that's only going to get you 193 miles. That's a 3.3% loss. Probably not enough to account for your "much less" observation.

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.

Up to 15% in winter. But as xvxvx pointed out, they're going to extend it into this summer.

Gasoline and diesel usually sell by volume, and if the temperature of the fuel is cold when you purchase it, you get more kilos per volume than you do when the dispensing tank is warmer.

There is quite a bit more expansion & contraction of hydrocarbons with temperature than many peoople expect.