Tag Archives: engine
Fuel Mileage How To Improve It
As fuel prices climb people naturally look for ways to increase the miles per gallon. At the same time shysters start heavily promoting engine and fuel additives as well as “Miracle” products to improve car fuel economy to a public that wants to believe.
Unfortunately most of those products are based on unsubstantiated claims. Those that present “scientific” results generally either have too little supporting data to be conclusive, poorly conducted experiments, or results that cannot be substantiated by anyone other than the product’s manufacturer.
There are things you can do to increase your fuel mpg. The first group of fuel saving tips has to do with you. The second group is about your car. Both groups are needed so that you might achieve those fuel mileage ratings.
Change Driving Habits
Slow Down, Drive Smoothly – Avoid fast/full throttle acceleration from a standstill. Avoid high cruising speeds on the interstates. Optimum gas mileage for highway cruising speed varies by vehicle and driver however faster is almost always worse.
Empty Your Trunk – Remove unnecessary items in your trunk. It takes power to move increased weight even in SUVs with good gas mileage, and that increased weight means more gasoline consumption and reduced performance.
Avoid Extended Idling – There is no reason to idle your engine until it reaches operating temperature. Idling cost gas mileage.
Combine Trips – Combine errands or trips so that the vehicle only needs to warm up once to encompass many different stops. Plan your route so that you drive less miles but accomplish the same tasks.
Vehicle Maintenance and Considerations
Use Proper Viscosity Oil – Always use the proper viscosity oil in your engine. Oil that has a higher than required viscosity will create more drag on the internal components of the engine. Many shops recommend increasing the viscosity as the vehicle ages, but this is wrong. This causes the engine to work harder especially when cold and reduces the gas mileage at all times.
Tire Pressure – One of the largest contributors to poor fuel mileage and increased safety risk is under inflated tires. Tires low on pressure create drag which the vehicle’s power train must overcome thus reducing the cars fuel efficiency. Always keep your tires inflated to the proper pressure as shown on the vehicles placard. Perform this check and adjustment on cold tires. You may want to consider increasing the pressure by a couple PSI, but not above maximum pressure indicated on the tires. This serves to increase gas mileage and cuts down on tire wear, which further decreases your operating costs per mile.
Air Filter – A vehicle that has a dirty air filter or a restricted duct can’t efficiently draw air into the engine. This restriction whether it is the air filter or a duct problem forces the engine to expend energy to “breathe” and reduces the cars fuel efficiency.
Use the Proper Grade Fuel – Purchasing higher than required grade (octane) fuel is a waste of money. It has been shown that higher octane (grade) fuels are more prone to carbon build up, which requires cleaning and can cause reduced fuel mileage because of an over active Electronic Spark Control System. Using higher octane fuels in a vehicle that only requires regular fuel will neither increase performance nor improve gas mileage.
Spark Plugs – Even though many vehicles have 100,000 mile service intervals for spark plugs. Most vehicles including SUVs with good gas mileage can benefit from replacing them at 60,000 mile service. If your vehicle is at that point, have the spark plugs changed to assure proper running and continued fuel efficient, trouble free operation.
Check Engine/Service Engine Soon Light – Is the Check Engine/SES light on? When this light is on, the vehicles On-Board diagnostics (OBD II) computer has noticed that something is wrong. Vehicles have many sensors that the computer uses to both control and sense actual fuel usage. When the Check Engine/SES light illuminates it signals that the OBD II system has lost some ability to run efficiently. Typically when this happens it substitutes a programmed value for a sensor, which is not as fuel efficient as the correct readings from the sensor. This typically results in increased fuel consumption, increased emissions, and/or driveability problems.
Removing Carbon and Cleaning The Air Induction System If it has been a long time since the last carbon and air induction cleaning, you should have your mechanic perform this service. Using something like the Mighty VS7 system or GMs Top Engine Cleaner will remove the carbon from the combustion chamber and deposits from the air induction system. This will allow the engine to operate better for increased fuel mileage.
Vehicles With a Distributor If you have one of these vehicles and after you have cleaned the carbon, and verified the performance of your EGR system, you may be able to advance the ignition timing by a maximum of 2 degrees from specifications. If you can this will improve your fuel mileage and performance, however if you notice spark knock (detonation) reduce the timing, but not lower than specifications.
If you wish to view a list of some of the engine and fuel additives as well as the “Miracle” products that have been tested by the Federal Trade Commission please visit their site at