Saving Gas Money in the Face of Gas Price Rise
Update, March 10, a poll by AAA on American’s how and when they are planning to adapt to the rising gas prices. With the price of gas greater than $4 a gallon, 59% of Americans will adapt their driving habits. In the age group 18-34, 29% would carpool, while for 35+, only 11% would. They will combine trips and errands, and cut shopping and dining out. If the price of gas exceeds $5 a gallon, 75% would make changes, and 80% would drive less. Gas has increased by 38% nationwide this year, and the national average is now $4.32 a gallon. California’s average cost for a gallon is $5.69 today, with LA County at $5.78, Orange County at $5.76, and San Diego County at $5.71 a gallon.
A barrel is 42 gallons, but crude can be made into many petroleum products as well as gasoline. A barrel yields 19 gallons of gasoline. If oil usage were elastic, meaning we adjusted consumption to the price, we would respond to the steep price rise by driving less, more economically, and carpooling where possible. There is also combining destinations in an economical way. Then using the most energy saving car for longer commuting drives. Cars now also have an economy setting to stretch out the gas usage. Something we didn’t have before was home or office delivery for food or items in an energy saving way. Finally, many people who could work from home are already set up for that, and could save gas and pollution by spending some days working at home or at a local business hub.
American autos are designed with a plateau in efficiency from about 25 to 55 mpg, and then their efficiency declines. There is also high wind resistance which uses 40% of the energy at 55 mph, and then increases exponentially after that.
Table of Engine Efficiency Loss with Speed from mpgforspeed.com.
| Speed | Loss of Efficiency |
| 55 mph | 0% |
| 60 mph | 3% |
| 65 mph | 8% |
| 70 mph | 17% |
| 75 mph | 23% |
| 80 mph | 28% |
Calculation of energy savings at various gas costs. The first one is for the price of $5.40 a gallon that I just filled up at the unnamed UC Irvine campus gas station in California. The table is from mpgforspeed.com
The average price of gas over the US today is $4.17 per gallon. The effective MPG and cost increase table for that is below from mpgforspeed.com.
If you should be lucky enough to find a stretch of freeway that you can commute at 80 mph, slowing down to the actual legal speed limit at 65 mph would save you $2,113 minus $1,653 equals $460 a year if you commuted every day of the year. Over 365 days commuting, that would be the $1.26 a day difference between $5.79 a day and $4.53 a day.
If you just commute 5 days a week for 50 work weeks a year, the 250 days commuting times $1.26 a day would save you $315 a year. Compared to a someday $15 per hour minimum wage, that would be equivalent to 21 hours of extra pay, or two days and 5 hours extra work. While you would be driving 5 extra minutes a day, it would be much more stress free at 65 mpg, and would also save on speeding tickets, court appearances, and hours of driver safety training on the weekends.
The conversion factor for the last column from the 365 day commute to the 250 day commute is just the factor 250/365 = 0.685, or about two-thirds.
Another way to look at the table, is that the vehicle which you bought that promised 30 mpg but only read 21.6 mpg on your mpg reading while driving 80 mph, will now suddenly be reading 27.6 mpg, close to the promised value. Hallelujah!
Unfortunately, the cost of gas in California had risen to $6.00 a gallon in places, so we include that price in this article now.
At 80 mph, Californian commuters can be paying an extra $927 a year in gasoline costs, and extra 44% than the rest of the US.
