winter gasoline = increased fuel consumption

NewJLU2019

Well-Known Member
Joined
Jul 19, 2019
Messages
934
Reaction score
1,472
Location
Wylie Tx Suburb of Dallas
Vehicle(s)
2021 Rubicon Unlimited 2019 Sahara Unlimited
Occupation
Retired Now
Vehicle Showcase
1
Every spring gas prices seem to skyrocket to the highest prices of the year. Why does this happen? In explanation, we hear the experts say that many of the refineries are “down for maintenance while transitioning from winter-blend to summer-blend gasoline,” but what does this mean?

The difference between summer- and winter-blend gasoline involves the Reid Vapor Pressure (RVP) of the fuel. RVP is a measure of how easily the fuel evaporates at a given temperature. The more volatile a gasoline (higher RVP), the easier it evaporates.

Winter-blend fuel has a higher RVP because the fuel must be able to evaporate at low temperatures for the engine to operate properly, especially when the engine is cold. If the RVP is too low on a frigid day, the vehicle will be hard to start and once started, will run rough.

Summer-blend gasoline has a lower RVP to prevent excessive evaporation when outside temperatures rise. Reducing the volatility of summer gas decreases emissions that can contribute to unhealthy ozone and smog levels. A lower RVP also helps prevent drivability problems such as vapor lock on hot days, especially in older vehicles.

The US Environmental Protection Agency (EPA) says conventional summer-blend gasoline contains 1.7 percent more energy than winter-blend gas, which is one reason why gas mileage is slightly better in the summer. However, the summer-blend is also more expensive to produce, and that cost is passed on to the motorist.

The switch between the two fuels happens twice a year, once in the fall (to winter-blend) and again in the spring (to summer-blend). The changeover requires significant work at refineries, so oil companies schedule their maintenance for those times when they will already be “down” for the blend switches.

As a consumer, the main thing to understand is that there are real reasons for the switch from winter- to summer-blend fuel, even if it results in some pain at the pump.
 

geem03

Well-Known Member
First Name
Gary
Joined
Oct 19, 2019
Messages
724
Reaction score
1,756
Location
New Brunswick Canada
Vehicle(s)
2019 Jeep Wrangler Sport
Occupation
RN/ Firefighter
Vehicle Showcase
1
Here in New Mexico it's around the start of November through the end of March. Our JL mpg goes down about 10% in winter unless I find a station on our road trips that sells Ethanol-free gas.
So does ethanol free gas give better gas mileage?
 

viper88

Well-Known Member
First Name
Nick
Joined
Apr 22, 2018
Messages
3,417
Reaction score
3,162
Location
IL
Vehicle(s)
'19 JLR 2.0T
So does ethanol free gas give better gas mileage?
I live in IL, right in the the corn-belt, so almost all of our gas has ethanol. Years ago I did find ethanol-free gas and tried it for several tanks. It was not a scientifically controlled study or test but I think got better MPG with ethanol-free gas. It also cost more so any improved MPG was probably offset by the additional cost.

https://www.roadandtrack.com/car-culture/a17240/how-does-ethanol-impact-fuel-efficiency/

https://www.cars.com/articles/anoth...may-vary-for-the-worse-ethanol-1420663037150/
 
Last edited:

geem03

Well-Known Member
First Name
Gary
Joined
Oct 19, 2019
Messages
724
Reaction score
1,756
Location
New Brunswick Canada
Vehicle(s)
2019 Jeep Wrangler Sport
Occupation
RN/ Firefighter
Vehicle Showcase
1
I live in IL, right in the the corn-belt, so almost all of our gas has ethanol. Years ago I did find ethanol-free gas and tried it for several tanks. It was not a scientifically controlled study or test but I think got better MPG with ethanol-free gas. It also cost more so any improved MPG was probably offset by the additional cost.

https://www.roadandtrack.com/car-culture/a17240/how-does-ethanol-impact-fuel-efficiency/

https://www.cars.com/articles/anoth...may-vary-for-the-worse-ethanol-1420663037150/
Out here in the east coast of Canada, we can get ethanol free gas but it comes at a higher price... like you said...I am assuming the cost offsets the mileage gains....
 

blnewt

Well-Known Member
First Name
Brad
Joined
Oct 8, 2018
Messages
4,098
Reaction score
4,029
Location
New Mexico
Vehicle(s)
2019 Jeep JL Sport S, 03 Toyota 4Runner, Infiniti G37, Toyota T100 (Retired 74 CJ-5, 80 CJ-7)
So does ethanol free gas give better gas mileage?
The corn mix in ethanol is similar to a filler, if you have 10% ethanol you can expect close to 10% less mpg vs ethanol-free fuel. Not sure, but the flex fuel vehicles that can accept E85 should burn Ethanol more efficiently AFAIK.

Used to run Ethanol-free fuel w/ our Infiniti G quite often, and the increase in mpg was almost exactly 10%. Haven't found Ethanol too often w/ our JL to get as large a sample size, but it did go up a couple mpg in those few times I've used it.

And yeah, if the cost of Ethanol-free fuel is greater than 10% the savings is a wash, but for those of us 2dr JL owners w/ dinky 17 gal tanks we need all the extra mpgs we can get :(
 

geem03

Well-Known Member
First Name
Gary
Joined
Oct 19, 2019
Messages
724
Reaction score
1,756
Location
New Brunswick Canada
Vehicle(s)
2019 Jeep Wrangler Sport
Occupation
RN/ Firefighter
Vehicle Showcase
1
The corn mix in ethanol is similar to a filler, if you have 10% ethanol you can expect close to 10% less mpg vs ethanol-free fuel. Not sure, but the flex fuel vehicles that can accept E85 should burn Ethanol more efficiently AFAIK.

Used to run Ethanol-free fuel w/ our Infiniti G quite often, and the increase in mpg was almost exactly 10%. Haven't found Ethanol too often w/ our JL to get as large a sample size, but it did go up a couple mpg in those few times I've used it.

And yeah, if the cost of Ethanol-free fuel is greater than 10% the savings is a wash, but for those of us 2dr JL owners w/ dinky 17 gal tanks we need all the extra mpgs we can get :(
Tell me about it! I feel I'm always at the pump!!!
 

viper88

Well-Known Member
First Name
Nick
Joined
Apr 22, 2018
Messages
3,417
Reaction score
3,162
Location
IL
Vehicle(s)
'19 JLR 2.0T
The corn mix in ethanol is similar to a filler, if you have 10% ethanol you can expect close to 10% less mpg vs ethanol-free fuel. Not sure, but the flex fuel vehicles that can accept E85 should burn Ethanol more efficiently AFAIK.

Used to run Ethanol-free fuel w/ our Infiniti G quite often, and the increase in mpg was almost exactly 10%. Haven't found Ethanol too often w/ our JL to get as large a sample size, but it did go up a couple mpg in those few times I've used it.

And yeah, if the cost of Ethanol-free fuel is greater than 10% the savings is a wash, but for those of us 2dr JL owners w/ dinky 17 gal tanks we need all the extra mpgs we can get :(
Truth!
 

geem03

Well-Known Member
First Name
Gary
Joined
Oct 19, 2019
Messages
724
Reaction score
1,756
Location
New Brunswick Canada
Vehicle(s)
2019 Jeep Wrangler Sport
Occupation
RN/ Firefighter
Vehicle Showcase
1
I've got a question!?!

Could one replace the jl fuel tank with a jlu fuel tank?

Would there be enough room?
 

viper88

Well-Known Member
First Name
Nick
Joined
Apr 22, 2018
Messages
3,417
Reaction score
3,162
Location
IL
Vehicle(s)
'19 JLR 2.0T
I've got a question!?!

Could one replace the jl fuel tank with a jlu fuel tank?

Would there be enough room?
Nope. Your best bet for a little more range in the wilderness is probably external gas cans.
 
Last edited:

Advertisement




Icon Vehicle Dynamics
 



Advertisement
Top