Why we need a summer gas blend

Q: The oil companies say they had to raise the price of gasoline to produce what they call the “summer blend.” Will they reduce the price when they start shipping the “winter blend”? My vehicle’s engine runs at a constant temperature controlled by a thermostat, so why do they have to have summer and winter blends?

A: Were you ever dumped by a woman who tried to make you feel better by using the classic breakup line, “It’s not you. It’s me.”?

Well, there’s sort of a similar answer to your question. It’s not your car. It’s their gas. To meet government regulations and keep prices lower overall, oil companies reformulate their gasoline in the spring and fall. Here’s why without, hopefully, losing you in too much scientific gobbledegook:

If you leave an open container of gas sitting out, substances known as volatile organic compounds — or VOCs — are going to evaporate just as water does. Science has determined these VOCs are bad for the environment, because they can increase the intensity of the smog caused by atmospheric ozone. Considering that the U.S. alone used an estimated 140 billion gallons of gas last year (about one gallon for every American per day), you can see the potential impact of these rogue VOCs on the atmosphere.

To try to limit these emissions, all gas blends are rated by a system known as the Reid Vapor Pressure or RVP, which is measured in pounds per square inch (like your car tires). Simply put, the higher a gasoline’s RVP, the more prone it is to vaporize. So to keep it from vaporizing, the government requires all gas to have an RVP of less than 14.7 PSI, which is the normal average atmospheric pressure. Gasoline with higher RVPs would give off those nasty VOCs increasingly more rapidly.

OK, you ask again, why can’t you just use one blend of gasoline all year? Because there’s another complication. Remember, I said that as temperatures increase, so do VOC evaporation rates? To counteract the dreaded heat of our Midwest summers, the government limits a gasoline’s RVP to between 7.8 and 9.0 during the hottest months of the year. The numbers are then relaxed in the fall and winter months when VOC evaporation is slowed by the colder temperatures. (The exact number depends on where in the country you live. There are nearly two dozen different blends of gas produced to meet various state and federal guidelines.)

To meet these RVP rules and changing climate conditions, the oil companies change their blends — and, believe it or not, it’s in the best interest of your wallet that they do so. When they’re allowed to produce gas with a higher RVP for winter usage, they can blend in butane, which is relatively plentiful and cheap, with gasoline. Thus, prices can drop in the winter.

But butane has an eye-popping RVP of 52, which would be strictly verboten in the summer. As a result, the summer formulation to meet the stricter RVP rules is more expensive. Adding to the increase is the fact that plants must shut down for a bit to rejigger the flow of various ingredients. In the end, prices rise, but, companies argue, your overall annual gas bill is less than it would be if they didn’t return to a cheaper blend in the fall.

Your other question — do prices actually go down in the fall — is much trickier to answer because the price you pay at the pump is based on other factors. If the price of crude oil suddenly starts exploding in, say, November, prices may increase despite the cheaper blend. The same is true if a couple of major plants shut down because of production problems or if, for whatever reason, there would be a sharp increase in consumer demand for gas.

I guess the best way to answer your question is to ask you to look at a chart of average retail gas prices throughout the country on www.gasbuddy.com. If you examine, say, a five-year period from Aug. 3, 2011, you’ll go on a roller coaster ride that often has peaks in the summer and troughs in the fall and winter, indicating that prices do indeed change both ways with the seasons.

Last year, for example, gas was about $2.05 on Feb. 3, climbed to $2.81 on June 16 and then dropped like a rock to $1.69 last Feb. 16. So far, this year’s path seems similar, peaking at $2.36 in early June before falling to as low as the $1.99 I paid at the Belleville MotoMart on Wednesday. Tumbling oil prices because of a current glut are certainly playing a role, but oil companies say the changing formulations remain a factor in this complicated relationship.

Q: About your recent column on the October 1952 plane crash in West Belleville: We have lived in the 7900 block of West A Street for more than 45 years. Back in the 1970s, our son found a .50-caliber shell casing in the woods behind our house. We have had it all of these years, but until we read your article, we had never heard the whole story of the crash. Is there a possibility that this shell is from that plane? According to our research, it was made in 1945 at the Des Moines Ordinance plant.

A: Although nobody would offer a 100 percent link from a simple description, I would say the chances are very strong that you have a remnant from that black October Friday when 2nd Lt. Carlos del Mercado’s P-51 exploded in the sky, leaving a trail of wreckage from 59th Street to Mount Carmel Cemetery.

Here’s the big clue: “The plane was heavily loaded with .50-caliber ammunition, which scattered over the area,” according to an Associated Press account later that day. Some shells even exploded, according to other reports.

As a side note, my friend James Haeman, of Belleville, called to say that he was working at Scott Air Force Base at the time. Shortly after the crash, he said, all of those .50-caliber guns were removed from the planes and replaced with dead weights to prevent civilians from being hurt in a future disaster while maintaining the plane’s aerodynamics.

I also should set the record straight on one other matter. Without thinking, I copied from one account of the tragedy the fact that “one of the plane’s engines” fell into a backyard on West Washington Street. I should have realized the P-51 has only one engine. Thanks to Norman Vitez, Belleville’s well-known cookie-jar man, for setting me straight.

Today’s trivia

What may have been the first stadium with a retractable roof?

Answer to Friday’s trivia: What color are bluebirds? Silly question, right? Well, not so fast. If you took a feather from a bluebird or blue jay and ground it up, the resulting powder would be brown, not blue, says Josh Brown at the American Council on Science and Health. How could this be? It turns out that Mother Nature endowed these birds with a protein called keratin along with zillions of teensy-tiny air pockets in their feathers. The combination works like a prism so that when light hits the feathers and encounters these keratin-air nanostructures, all colors pass through — except blue, which is reflected. Thus, you see a blue bird even though it’s really not. However, if you ground up a cardinal’s feather, you would wind up with red powder, Brown assures us.

This story was originally published August 5, 2016 at 9:23 AM with the headline "Why we need a summer gas blend."