Winter blend gasoline VS Summer blend ?

Which is better ?
Not sure what the difference is,
Winter blend is easier to produce, & a bit cheaper.
What's in the summer blend that makes it cost more & handle
the higher ambient temperatures ?

Popular mechanics article:
"During the summer heat, the RVP of gas has to be especially low to keep it from boiling off. The EPA mandates an RVP maximum of anywhere between 9.0 PSI and 7.8 PSI for summer-grade fuel, depending on region (though you get a fudge factor of 1 psi for using gas blended with 10 percent ethanol). There are even lower RVP-rated fuels for cities like Houston, New York, and L.A. Different states and cities have their own rules based upon their seasonal temperatures—Washington state needs different summer gas than, say, Florida. That’s why there are so many blends. To make it more complicated, the time for switching from summer- to winter-blend gasoline varies by state too.

Generally, the lower the RVP of a gas blend, the more it costs. For example, in winter you can blend butane, which is relatively plentiful and cheap, with gasoline. But butane, which has an RVP of 52 on its own, can’t be used in summer, when it would immediately boil off as a gas. So "purer" summer gasoline is by default costlier. (And there are other factors at play too. More people travel in summer during peak driving season, for instance, putting more stress on demand.) "

http://www.popularmechanics.com/car...-blend-gasoline-whats-the-difference-13747431

So what does that mean for chain saws, which is better ?
What gasoline is in the pre-mix you can buy now(winter or summer blend)?

My thoughts are the summer blend is better, purer gasoline, flash point is lower so less high end evaporation in a vented saw tank . Should store better in a sealed jug & less vapor flash off during use.

I do notice my plastic gas jugs like to swell , due to the vapor pressure.
Maybe a good , tight metal jug is better gasoline storage. ?

 

All I know is my Jeep loses 2 mpg as soon as the cold hits.

 

Heavier loads, fuel & thicker lubes ?

 

I suspect pushing a box through colder, more dense air is also a factor.

 

Being a mechanic,and used to sell bg products(44k is still the best )you all are right.Out here winter blend is allowed to add more products(ethanol mostly) for better cold weather starting and decreased emmissions.Quite some time ago they only told us it was "oxeganated" fuel.Ran fine,poor mileage.Also when temps got below -15 a chemical reaction happened in fuel tanks,and a fine brown powder plugged intank filters,burned up pumps and injector problems.A lot of gas stations got blamed needlessly,this is your government at work.Out here it is winter blend 8-9 months of the year.So when you go to a pump that says"no ethanol" for regular,not true if it is winter blend,as they do not use the other oxagenator chemicals anymore.Just found out my buddy that has one of the last independant stations,that has ethanol free,put the station up for sale,don't know what I'm going to do for my small engines.And by the way,anything ethanol produces less hp per gal,so you use more fuel to go the same distance.So your emmissions are less,but you are using more fuel,another lie about ethanol.

 

Like driving up hill all the time with the tires packing down snow.
Walking & driving on sand in the winter would be better, Hawaii, Florida

 

Yep,burned up a lot of gas in the 70's in N carolina,surf fishing,tires at 10 psi,don't slow down in the soft spots or have to get the anchor and come a long out!Good times though!

 

Winter blend is garbage.
My CRV dropped from 26.5mpg down to 20.8 3 weeks ago

 

It's all about the "light-ends"- gaseous hydrocarbons that are added to winter-blend gasoline. Stuff like methane, ethane, propane, butane. For cold-starting, they give the sparks something to ignite. That's what the "RVP" thing was about- "Reid Vapor Pressure".

Liquid fuel won't burn. Vaporize it and away we go. Come summer and they'll cook off; don't need it then anyway.

Avgas has a different problem. Light ends can get you vapor lock up around 10-15 thousand feet. Flameout and coast. So, not much light ends in avgas- makes for interesting complaints when folks run it in a chainsaw, sometimes.

Nobody should be burning up all that corn-likker.

 

Modern automatic transmissions burn a lot of fuel by leaving the torque converter unlocked until it gets up to temp.

 

My 6r80 doesn't lock up for several miles when it's 20 or below. Not saying there's anything wrong with that. ..just the way it is.

 

I had a Ford Ranger that actually got better gas mileage in the winter. But the rest of my cars all drop 1-2 mpg with the winter blend. You can tell when they change the blend, because it's an immediate change from one tank of gas to the next.

 

My 96 ranger was the same way. The butt dyno said it made better power too (not that a Ranger makes a lot of power).

 

Totally agree,his statement makes no sense.If you lock up convertor before all other operating systems are up to par you are actually wasting fuel.By the way master,I have put lock up convertors in th400's,Almost put one in my pellet hauler,J100 jeep golden eagle 401,used to haul a camper,but ran the numbers and would take 10 years to pay off the savings?Kind of like solar?

 

Only over a period of time,cost factor.