Switch to Summer Fuel?

[The Critic]

I noticed that starting with two fill-ups ago, I have been averaging about 2 mpg more (5%) than usual. It was coincidentally the same time that I began using RLI Bio-Plus.

However, someone mentioned the switch from winter fuel to a summer blend. Does anyone know when that switch takes place?

 

[dparm]

It varies based on geography. Winter gas is used for shorter periods as you go further south. I'm sure there's some formula based on average temperatures.

Chicago, for example, is September 15 - April 15.

 

[dparm]

http://www.theoildrum.com/story/2006/9/13/234043/431

http://www.theoildrum.com/node/2374

 

[Indydriver]

IDK but, here in Indy we got a nice .35-.40/GL increase over the weekend.

 

[shanneba]

Winter blend should be from December to March 1, at least here in the midwest. CountryMark shows these dates:

http://www.countrymark.com/documents/user_assets/Gasoline%20Specs%20(02-15-11)%20Rev-21.pdf

SUMMER - April 10 – Sept 15
LOW INTERMEDIATE - September 16 – September 30
HIGH INTERMEDIATE - March 1 - April 9 and October & November
WINTER - December - February

 

[ahoier]

Wow, that's good news.....but in a way alarming too

Seems almost "too soon"....then again, according to my calendar, "Winter" actually doesn't "begin" until December 19-25th somewhere in that range....but I know it was very cold before that date We had a very cold "Fall" I guess you could say....and a milder Winter

 

[InvalidUserID]

I hope the winter gas goes away soon as I've noticed a 10% (give or take) drop in MPG the past few months.

 

[morris]

one thing that is involved is the reid vapor pressure. its an good read, no pun intended. but i havent looked at in a while.

 

[mechtech2]

Reid vapor pressure was more critical with carbureted cars that needed the fuel to atomize quickly in the manifold.
Port FI cars are not so greatly influenced.

 

[shanneba]

Reid vapor pressure also affects the evaporation of gasoline -


Volatility is the property of a liquid fuel that defines its evaporation characteristics. RVP is an abbreviation for "Reid vapor pressure," a common measure of and generic term for gasoline volatility. EPA regulates the vapor pressure of gasoline sold at retail stations during the summer ozone season (June 1 to September 15) to reduce evaporative emissions from gasoline that contribute to ground-level ozone and diminish the effects of ozone-related health problems.

To see the regualtions and RVP levels for your State/Counties -
May through September 15th

http://www.epa.gov/otaq/fuels/gasolinefuels/volatility/standards.htm

 

[Cutehumor]

Originally Posted By: The Critic
I noticed that starting with two fill-ups ago, I have been averaging about 2 mpg more (5%) than usual. It was coincidentally the same time that I began using RLI Bio-Plus.

However, someone mentioned the switch from winter fuel to a summer blend. Does anyone know when that switch takes place?


gas prices are blowing up this summer. good thing, you got that Prius. I vaguely remember you didn't like it at all when you got it.

 

[morris]

see i for got you cats know more about this stuff than i do. and mechtech2 is right the newer engines are more forgiving. wish i dime for ever time a throttle plate froze at 40 -45 f temp with high moisture.