Summer Gas Blend & Better MPGs

[johnnyd2k2]

Now that we should all be getting the summer gas blend I was curious if people are getting better MPGs. I've noticed over the last 4 tanks about a 10% increase over what I got durring the winter months. I know there are a lot of variables involved here but I know once the winter blend came out my MPGs dropped noticably. So am I crazy or am correct to think that the max likes the summer blend or maby just the warmer weather?

[MadMax07SL]

What is a Winter Blend? I'm from FL, is this a northerner thing?

[NismoMax80]

what blend?

warmer air temps provide higher MPG. i thought that ethanol was 10% pretty much all around now. heard "they" were pushing to increase it though

[nissandrvr98]

Maybe to shine a little light in here...maybe not

The term "summer blend" is shorthand for a menu of federally and locally mandated summertime fuel recipes that are designed to cut down on smog. The gasoline we use is always refined from an intricate blend of ingredients; the process combines coffee-dark crude oil with various additives that increase performance or make fuel burn more cleanly. Because overlapping federal and local requirements call for different recipes in different locales and seasons, there are approximately 20 distinct "boutique blends" of gasoline sold in the United States. Some Americans end up pumping a blend called Carb (named for the California Air Resources Board) while others burn Atlanta (named for Georgia's capital, where it's sold).

Refineries brew their summer blends by removing hydrocarbons that are more prone to evaporate in hot weather. These chemicals, called volatile organic compounds, react with airborne pollutants in the summer sun to form ozone, one of the main components of smog. From June 1 to Sept. 15, the EPA mandates that pumps in 12 high-ozone urban areas—such as Los Angeles, New York City, and Baton Rouge—deliver gasoline that meets special low-evaporation standards. Several states have voluntarily adopted the rules, and 15 have enacted their own seasonal-blend regulations on top of the EPA's. For example, pollution-conscious California has mandated that service stations must start selling its summer blend in May.

Summer-blend gas isn't new. It was first sold in 1995, as required by the Clean Air Act's 1990 amendments, and the current, even cleaner, concoction was phased in for the summer of 2000. Since then, there have been sharp spikes in fuel prices every spring as summer blends get rolled out. This is not so much because it's expensive to make the gas—the added cost per gallon is only 1 or 2 cents—but because refineries generally try to sell every last bit of winter fuel before mixing in the slightly more expensive summer batch. Sometimes they draw down the stock too far, creating shortages before the first deliveries of summer blend enter the supply chain. The return to normal blends in the fall causes a far less pronounced spike because the industry, free from summer standards, doesn't bother selling off the summer gas before mixing in the less pricey stuff.

So why not use the summer blend year-round? The main reason—apart from the fact that the 1990 law isn't written that way—is that summer-blend gas doesn't work as well in the winter. Summer blend's low-evaporation rate makes engines less likely to stall in hot weather but can make them difficult to start in the cold.

i learned something...and thats why i hang out here

[xWasX08]

Im noticing more MPGs 2... I live here in MA and the winter MPGs suck.. at least for me. Summer for gas is great, although theres a hike in prices. Theres always a plus/negative side.

And +1. ^ Ever since I joined this site and even before (browsed as a guest for a LONG time.) Ive learned so much about cars in general and also my Max. Love it.

[NismoMax80]

I just spent half an hour cleaning my stuffed K&N filter... hope that helps a little

[SilverMax_04]

The information in the 4th post seems to be reasonably accurate, but not complete. I worked in the oil industry for 35 years before retiring in 1998. Points I would make:

- The posting implies that "coffed-dark crude" is blended with additives. In fact, the crude is first refined into hydrocarbon components and these different components are then blended with additieves to meet a range of different specifications - in addition to volitility. Also, not all crude oil is "coffed-dark" - it comes in all different shades from "cow-piss" yellow to black.

- There were winter and summer grades of gasoline before the law was passed in 1990 (or so). Before the law, oil companies worked to make the cheapest gasoline without having customers with vapor lock (which occurs with carburators and winter grade gasoline on a warm day).

- It is cheaper to make winter grade gasoline because it is possible to blend more butane into the fuel than you can in the summer, when you essentially can not use any Butane in gasoline. Butane is relatively cheap and has good octane properties. It also greatly helps an engine start when the temperature is 10 degrees below zero.

- I believe there are more than 20 different mandated gasoline blends across the USA in the summer time. One reason the prices get so high - too many politicians getting into the act and making production of gasoline more difficult and expensive with all of the slightly different specifications by political district.

- I suspect, but can't prove, that it costs more than 1 to 2 cents more per gallon to make summer grade versus winter grade gasoline.

Hope this helps clarify some to the points in post # 4.