Relationship between speed and mpg

Relationship between MPG & Average speed | PriusChat

relationship between speed and mpg

Gas is made up of a mix of molecules—all in the same family, but Ridge, tested cars' fuel economy at speeds over 50 miles per hour. the front of the car, which is what makes by far the largest difference in wind resistance. Average decreases in fuel economy for all cars in the sample were 8% from 64 to Sensitivity of the fuel consumption rates to speed increased with increasing. What you are asking is what constant speed will give the best mileage. The letter v represents the velocity of the car, and the letters a, b and c represent three .

The graph on the right is based on EPA and fueleconomy. There are many factors that affect fuel economy, however, and these figures can vary significantly. To learn how to calculate your gas mileage, read our guide. Older vehicles, however, may need more idling time when first started.

Five properties of physics that affect your gas mileage

In cold, wintery conditions, all vehicles may need more idling time to warm up and ensure the windshield is fully defogged. Be sure your vehicle is warmed enough to prevent stalling when you pull out.

Start by checking tire pressures in your driveway. Note any tire that is underinflated, and then drive to the nearest gas station to add air.

relationship between speed and mpg

Check tire pressures again at the station, and inflate the low tires to the same level as the others these will likely have higher pressure than they did in the driveway, since the tires have heated up. Radial tires can be under inflated yet still look normal. Always use your own tire gauge for consistent results.

On average, tires lose about 1 psi per month and 1 psi for every 10 degree drop in temperature.

relationship between speed and mpg

According to the Energy Information Administration, tire efficiency could save approximatelybarrels of oil a day. Select the Right Gear Change up through the gears and into top gear as soon as possible without accelerating harder than necessary. Driving in a gear lower than you need wastes fuel; so does letting the engine labour in top gear on hills and corners.

Automatic transmissions will shift up more quickly and smoothly if you ease back slightly on the accelerator once the car gathers momentum. Use the Cruise Control On long stretches of highway driving, cruise control can save fuel by helping your car maintain a steady speed.

However, this efficiency is lost on steep hills where the cruise control tries to maintain even speeds.

relationship between speed and mpg

In hilly terrain, it is best to turn off the cruise control. Many cars are designed to use regular low-octane fuel.

Most of the tips above apply to hybrid and gas-powered vehicles alike. You get energy by breaking the molecules apart. Short ones, like butane, have less energy, and they cost less so it makes sense that a company would want to add more of them.

relationship between speed and mpg

The part the EPA cares about is that short molecules also evaporate more easily, contributing to pollution. So in summer, the EPA restricts how many short-chain molecules can be in the blend, and your mileage increases because there's more energy in the gasoline overall.

Unfortunately, it also makes the gas slightly more expensive. For each extra 10 mph over, you lose a little over 12 percent of your miles per gallon. That increases as you go faster. Going from 70 to 80 mph costs you 15 percent, not Depending on the make of your car, it could be more or less.

Some cars dropped as much as 25 percent. So keeping the car going at 80 mph is using eight times the power you'd be using at 40 mph.

Relationship between MPG & Average speed

If the car is a box, that's bad," Ciatti said. You can see the coefficients of various shapes in the sidebar. You can demonstrate this effect yourself, Ciatti said, when you hold your arm out the window while you're driving on the highway. If you lay your hand flat, parallel to the ground, the force isn't too bad.

Fuel Efficient Driving | Eartheasy Guides & Articles

But if you hold your palm out, facing front, exposing more surface area to the direction of travel, the force is much stronger. That's the difference drag coefficient makes. Automakers today pay close attention to drag coefficientdesigning cars so that air slips easily around them.

  • Fuel Efficient Driving
  • MPG For Speed .com
  • Five properties of physics that affect your gas mileage

Choosing a car with an aerodynamic front—compared with a boxier make—will mean its gas mileage tends to be better. It takes a lot of power to get an object of that mass moving, but once it does, you can use the momentum to coast—especially during city driving, with frequent stops and starts.

relationship between speed and mpg