Winter vs Summer Gasoline Blend

[RAM Patriot]

I have noticed that my mileage usually drops about 1 MPG once my state switches over the the winter blends at the end of October.

I average about 19.5 MPG in the summer and drop to 18.5 MPG in the winter.

After some research I found out that: "Winter-blend gas has a higher Reid Vapor Pressure (RVP) because the fuel must be able to evaporate at low temperatures for the engine to operate properly. Summer-blend gas has a lower RVP to prevent excessive evaporation when outside temperatures rise."

What that means is that the refiners have to add butane to the winter gas so that it will ignite at lower temperatures making it more volatile in the winter.

This lowers the density of the BTU's meaning that summer blends have 1.7 percent more energy than winter blends.

This accounts for the drop in my fuel economy.

See the following article for more details:

The Vapor Rub: Summer versus Winter Gasoline Explained

Starting in 1989 before the 1990 Clean Air Act, the Environmental Protection Agency began restricting the volatility of retail gasoline sold in the summer. Here's why.

www.caranddriver.com

 

[ferraiolo1]

Us in the north loose even more than that.

Between the winter blend and warming the vehicle up.


Sent from my iPhone using Tapatalk

 

[Richard320]

All I can tell you is that in California, the price goes up because "we're switching to winter blend" and then a few months later the price goes up again because "we're switching to summer blend." I never noticed much in the way of decreased economy either way.

 

[millerbjm]

I don't notice a price change at the seasonal switch but certainly notice lower mpg on winter blend in MN as much as 3-4 mpg.

 

[RAM Patriot]

I don't notice a price change at the seasonal switch but certainly notice lower mpg on winter blend in MN as much as 3-4 mpg.

That is a significant drop in MPG's.

 

[2019REBEL]

Usually drops a few cents/litre here but with our carbon tax it might not this year. Thanks Trudope(Canadians will know who this is)

 

[CreepingDeath]

Colder weather means your engine has to work harder thus it's less efficient than in warmer weather.

 

[GM26J]

always a couple mpg less here in the winter because of the fuel blend

 

[Rammit]

I always knew there was a difference but didn’t know what was actually different. Nice write up and good information.

 

[zlman]

I don't notice a price change at the seasonal switch but certainly notice lower mpg on winter blend in MN as much as 3-4 mpg.

I'm seeing this too, also MN resident. I was getting a solid 18mpg all summer, averaging 16.1 now, exact same driving conditions.

 

[brian42]

All I can tell you is that in California, the price goes up because "we're switching to winter blend" and then a few months later the price goes up again because "we're switching to summer blend." I never noticed much in the way of decreased economy either way.

California gas prices also go up when there are refinery/pipeline issues on the East Coast.

 

[Scram1500]

Wonderful, gas that now costs a fortune gets less miles per tank. I can't imagine what will happen when Brandon shuts down another pipeline

 

[Idahoktm]

I'm seeing this too, also MN resident. I was getting a solid 18mpg all summer, averaging 16.1 now, exact same driving conditions.

Cold air is more dense than warm air, so your computer compensates by increasing the amount of fuel needed so your tuck doesn't run lean. Add that to a winter blend fuel and your mileage decreases by a couple mpg's. There is a positive...your engine produces more power in cold air. The perfect combination for a snow covered Minnesota road.

 

[truckless]

Usually drops a few cents/litre here but with our carbon tax it might not this year. Thanks Trudope(Canadians will know who this is)

You mean The Supreme Groper? The Titty Puncher? The Woman Disempowering Feminist? He Who Gives Untendered Government Contracts to Non-profit Organizations Who His Wife, Mother and Brother all get Financial Kickbacks? That guy?

 

[Scram1500]

You mean The Supreme Groper? The Titty Puncher? The Woman Disempowering Feminist? He Who Gives Untendered Government Contracts to Non-profit Organizations Who His Wife, Mother and Brother all get Financial Kickbacks? That guy?

Was that before, after, or during his dressing up in blackface?

 

[truckless]

Was that before, after, or during his dressing up in blackface?

Depends. Which time you are referring?