Saving Gas: Tips

  • Posted by a hidden member.
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    May 13, 2008 2:42 AM GMT
    Well it's big day here. Gas broke $4.00 per gallon at the expensive highway Mobil station. Not that I fill there but 3.93 at Shell is bad enough. Seeing as how gas isn't going to be going down substantially anytime soon I'd though I'd share a few tips and words.

    Overall there are countless tips and habits that can help save gas. Walking, mass transit, carpooling, etc are all way. If anyone wants to chime in this some feel free! FYI: Some of these tips can be illegal or dangerous if misused. Consider your own safety and the safety of others when attempting some of the more advanced techniques.

    Long post Alert! Consider yourself warned:

    First: Some definitions:

    FE = Fuel Economy
    mpg = Miles Per Gallon (duh*)
    ICE = Internal Combustion Engine

    To start: If your car doesn't have a fuel economy display then consider a device such as the Scangauge II. This device works in any modern car and displays not only instant mpg, but trip meters, lifetime, engine load, engine temp, accurate RPM's, and other features. Expert use of a device like this helps you track your progress FE wise and identify trends and driving patterns that lead to better FE.

    Basic FE related tips:

    Light acceleration and braking: This is the common sense one needing no explanation. Yes it's probably fun to gun the engine, lean into the turns, and tear up the pavement but your only wasting gas and wearing your your car faster. EPA numbers for cars are assumed using "light" driving on flat surfaces in good warm conditions. Obviously if you drive hills, winters, rain, or fast your NOT going to hit your numbers.

    Avoid higher speeds: Speed kills fuel economy. Depending on the car most work most efficiently inside a certain speed range. Generally speaking this range ends after 55 mph where wind resistance from higher speeds increases. At about 60-65 mph wind resistance doubles and increases even more at high speed. For modern highway driving staying under 70 is a big help.

    Example: Look below the Tach for the mpg at 50 mph cruise control vs 60 mpg cruise control:

    Avoid short trips: short trips kill FE, especially in cold weather. When you first start the car it goes into a more fuel thirty warmup of a higher fuel mixture and higher RPM's. If you have multiple short trips trying combining them all into one run, go to the furthest destination first to allow the car to warm up.

    Route Planning: Planning how your going to get somewhere can be a big aid to FE. Sometimes the shortest trip isn't always the best route. Consider routes that avoid excessive amounts of lights, hills, and traffic.

    Example: Below if I'm heading on Buckland Street and need to go east on Route 30 it looks like cutting along Deming street is faster than going further up the road. But in fact Deming cuts over a large hill while Staying on 30 avoids the hill. Test with Scangauge proved that the longer route was the more fuel efficient choice.

    Proper footwear: Wearing just socks, or any smooth bottom light shoe or sandal gives the best FE. Wearing blocky boots or ridged surface sneakers doesn't allow for the best foot pressure. Consider keeping a pair of clogs or crocs in the car for driving.

    Fill up in the morning: A small impact but over time it can add up. When you need gas fill up first thing in the early morning, when even underground gas can be slightly colder and hence more dense.

    Engine Block Heater: Offered for most cars and SUV's this is just a heater element that you can plug in to keep the engine block heated while parked. Useful in cold weather, it prevents the FE loss from cold starts especially in the northern climates. Even in the coldest weather my block heater keeps the engine bay at about 50 degrees F.

    Good selection: Good choices in what you drive. Consider cars with smaller engines, and if you need 4WD try for something that can switch out of 4WD instead of all time AWD. Generally speaking the smaller the engine the better the fuel economy. This is why a 1.8L Civic gets better FE than a 2.2L Focus.

    Third box for Advanced tips:

  • Posted by a hidden member.
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    May 13, 2008 2:43 AM GMT
  • Posted by a hidden member.
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    May 13, 2008 2:44 AM GMT
    Wasn't finished! icon_mad.gif

    More Advanced FE tips:

    Tire Pressure: Many cars will come with two recommended tire psi ratings. One in the car manuel, the other on the tire sidewall. The sidewall rating or normally higher. Example my car has 35 psi rating but the stock Bridgestones were 44 psi. Higher psi in the tires leads to lower tread wear and better FE through the ability to extend glides (discusses later). The result will be some possible additional road noise and vibration. While I will not comment on going above sidewall I will recommend staying max. The lower number provided by the carmaker reflects their desire to sell you comfort and performance.

    FAS: Force Auto Stop: FAS is forcing the engine off during specific conditions. When used right it can lead to FE gains. Used wrong it can damage an engine. The first condition is when at a stop. Wasting fuel at idle has no gain. The simple solution is shift to N then to Key off the car when at a long light then key back up once to power the electronics. Simply key back on the engine, shift and go at green. AN advanced setup can be used while in motion. Shifting to N, then keying down puts the car into glide mode without spending fuel. There is some loss of steering and this is of course illegal in some states. A note on an FAS while in motion is some cars need the engine to be on to lubricate the transmission. Read your cars manual. If you car CANNOT be towed on all 4 wheels then do not attempt an FAS in motion. This can also be used in hybrids when its to cold or conditions don't support the autostop. The CVT transmission is unaffected by FAS.


    P&G: Pulse and Glide: P&G is an alternative to constant speed driving that can have big FE gains. This technique can be used on both backroads and highways, best applied on long stretches of flat surfaces. You start by pulsing up to a set max speed, the doing an FAS at speed. The car will glide for a distance losing speed slowly. Once you hit you determined lowest desire speed simply restart and repeat the process. This takes effort and focus but a good glide with high psi tires can last for several thousand feet. This is the difference in a normal Accord between 28 mpg cruising and 48 mpg P&G runs. Note: Hybrid cars can do this without a FAS since the ICE ceases to consume fuel in most hybrids while gliding.

    DWL: Driving With Load: For situations with hills this is useful as it helps save fuel. Basically when you know a hill is coming up down the road you accelerate beyond normal driving speed in preparation. As you come into the rise, bleed off speed by holding steady on the pedal pressure. You will lose speed but your mpg will remain near constant. Example: a moderate highway rise you will go from 75 mpg - 55 mph while avoiding an FE drop. It helps to stay in the right lane for this or avoid it on one lane state roads. For smaller hills this works just as well without to much loss of speed.

    DWB: Driving Without Brakes: Basically drive pretending you don't have brakes. Sticking to a routine route know the lights and potential stops ahead of you. allow yourself to glide slower if needed to avoid a red light. Avoiding reds at all cost is the goal, because acceleration is a killer to FE.

    Rabbit Timing: When nearing a red light you have to trigger use "rabbit" timing by allowing someone else to be the "rabbit" Slow down if lanes allow and let others pass you and trigger the light so you can glide steady on through the green.

    PP: Potential Parking: Park facing out is possible and always on a rise. Reverse, especially after a cold start wastes gas, as does climbing a rise after a cold start. Allowing yourself the ability to just glide out with little pressure helps FE.

    Drafting: Drafting is traveling using the wake of another car or truck as a win buffer. Although it can be dangerous if abused it can lead to much better FE especially if your required to travel at a faster speed. Following in the wake of trucks in the common form, (although avoid this at night as the trucker will assume your a drunk driver and attempt to shake you). Also traveling in the far right lane at a lower speed than passing traffic creates a wind buffer effect leading to better FE as well.

    Fake Shifting: This can be done on VTEC and VVT engines.(Japanese: Honda, Acura, Toyota, Scion) Basically this is used on AT transmission cars where you slightly reduce foot pressure for a second then return the pressure. The Tach will drop slightly, "faking" the engine into less RPM's and a small FE gain.

  • GQjock

    Posts: 11648

    May 14, 2008 2:23 AM GMT
    a fill up on my car finally broke the $50 dollar mark
    My next car is SO gonna be a hybridicon_neutral.gif