Book on better gas mileage

I just came across a book on improving gas mileage and thought you might find it helpful.

Spark plugs and gas costs

You pay have never thought about this but if your spark plugs aren’t working effectively you’ll get lower gas mileage. This is another simple idea to help you save on gas.

Here’s some related stories:

Low resistance tires

Low Rolling Resistance Tires

Rolling resistance is fundamentally the parasitic energy a tire consumes while rolling under load. The phenomenon is quite complex, and nearly all operating conditions can affect the final outcome. It is estimated that 5%-15% of light-duty fuel consumption is used to overcome rolling resistance for passenger cars. For heavy trucks, this quantity can be as high as 15%-30%.

Some of the following documents are available as Adobe PDFs. Download Adobe Reader.

Sensitivity Coefficient

A modeling study conducted at the National Renewable Energy Laboratory, Analysis of the Fuel Economy Benefit of Drivetrain Hybridization (PDF 268 KB), shows the sensitivity coefficient (percent increase in fuel economy per percent decrease in rolling resistance) to be as high as 0.2 for a conventional vehicle. The current study quantifies this number by duty cycle and comes up with a range of 0.1-0.2. A report written by Green Seal (PDF 285 KB) indicates that a 1.5%-4.5% savings is possible for high rolling resistance tires. The same report quotes testing done for rolling resistance on tires with rolling resistance coefficients varying from ~0.01 all the way down to ~0.006 implying up to 3% improvement in fuel economy for a very low rolling resistance tire.

New vs. Replacement Tires

New cars are generally equipped with low rolling resistance tires that offer better fuel economy. This helps the auto manufacturer to meet their Corporate Average Fuel Economy (CAFE) standards. However, no requirements are currently placed on replacement tires. Therefore, if you want to purchase fuel-efficient replacement tires, you must research to figure out which tires have low rolling resistance.

Tire Inflation

Proper tire inflation also plays a large role in keeping vehicles fuel efficient. For example, a vehicle with a recommended pressure of 35 psi whose tires are at 28 psi will have increased its rolling resistance by 12.5%.

Cost Effectiveness

According to a California Energy Commission report, the use of low rolling resistance tires on light-duty fleets is cost effective over the life of the vehicle. That is, the fuel savings pays for the additional cost of the low rolling resistance tires. This report finds that the opportunity for cost-effective energy savings in California from low rolling resistance tires is substantial—about 300 million gallons of gasoline per year resulting from a 3% average improvement in the fuel efficiency of light-duty vehicles currently operating on replacement tires. For more information visit the California Energy Commission’s Fuel Efficient Tire Proceeding Documents Web page.

In the equation, it is assumed that the baseline rolling resistance is 0.009. RRC_replacement is the rolling resistance of the replacement tire which can be obtained from sources such as Green Seal’s Choose Green Report, March 2003 (PDF 285 KB) Download Adobe Reader. Negative values indicate an increase in fuel consumption.

Use the right grade oil

You  can improve your gas mileage by 1-2 percent by using the manufacturer’s recommended grade of motor oil. For example, using 10W-30 motor oil in an engine designed to use 5W-30 can lower your gas mileage by 1-2 percent. Using 5W-30 in an engine designed for 5W-20 can lower your gas mileage by 1-1.5 percent. Also, look for motor oil that says “Energy Conserving” on the API performance symbol to be sure it contains friction-reducing additives.

Keep your tires properly inflated

You can improve your gas mileage by around 3.3 percent by keeping your tires inflated to the proper pressure. Under-inflated tires can lower gas mileage by 0.4 percent for every 1 psi drop in pressure of all four tires. Properly inflated tires are safer and last longer.

Change your oil filter often

One good tip for improving your gas mileage is to change your oil filter often. The oil filter is a very important part of the lubrication system as it filters impurities from the oil. The smoother the engine runs the best gas mileage it will produce. You should change your filter at at every oil change for best results. There are many top name oil filters all producing quality products.

If you use Synthetic oil will be wise to pick a high grade performance oil filter. Keeping the engine well lubricated and free from broke down oil that becomes gummy will help maintain a better gas mileage and a healthier engine. A clean oil filter will decontaminate the oil and provide a better lubrication system for the engine. A clean oil filter will lessen the stress on your engine- and stress causes poor gas mileage and also lessens engine life.

Change your own oil

One easy way to improve your gas mileage is to change your oil often following your automobile manufacturer’s guidelines. Although having your oil changed by a gas station or other auto service provider isn’t that expensive, here’s info on doing it yourself. The process takes only 20-30 minutes.

Material You Will Need
1- The right grade oil for your car
2- An oil filter and filter wrench
3- A socket wrench and ratchet
4- An oil catch pan
5- Shop rags

Here’s the steps to change your oil:

1. Locate a level, paved area; and raise the vehicle by driving up onto ramps or by using a floor jack and jack stands
2. Set the parking brake, and chock the rear wheels to prevent roll back.
3. Locate the oil drain plug at the bottom of the oil pan, and place a catch pan underneath it.
4. Then, remove the drain plug, allowing the oil to drain from the engine. After the oil has completely drained, replace the drain plug – being careful not to over tighten.
5. Find the oil filter, and position the catch pan underneath it.
6. Then, remove the filter, taking care not to spill the oil that remains inside. If your oil filter does not have a built-in grip coating on the outside of the canister, you’ll need to use a filter wrench to complete this step.
7. Lubricate the gasket on the new oil filter with a small amount of new oil. This will ensure that the filter twists on smoothly, and that the gasket does not break off during installation.
8. Prefill the new oil filter half way with fresh oil to ensure that your engine has oil for the first start up.
9. Then, carefully screw the new filter into place. Tighten by hand until the gasket contacts the base; then turn, one additional turn. (Don’t overtighten because this can result in leaks)
10. Open the hood of the car, and remove the oil cap. Then, insert your funnel and refill the engine with oil.
11. To avoid overfilling, hold back the last half quart of oil – a certain amount of old oil will remain in your engine even after it has been drained.
12. Replace your oil cap.
13. Start your engine and allow it to run for one minute to circulate the oil. Then, turn off, and wait an additional three minutes for the oil to return to the oil pan.
14. Remove and inspect the dipstick. Add a small amount of oil if the dipstick reads low.
15. Then, recheck. Repeat until you reach the right level.

Note: Be sure to put your oil cap back on, if you had to add oil.