Difference between revisions of "Hypermiling Techniques"

b) carpool;

c) bicycle;

d) walk;

e) take public transit

[1]

DIY: MPGuino and others

MPG vs speed graph

EcoDriving 101 – Reducing Speed

2) coasting in neutral, engine idling; 3) regenerative coasting (hybrid vehicles) 4) regenerative braking (hybrid vehicles) 5) coasting in "deceleration fuel cut-off" mode (in gear, above a certain engine RPM) 6) conventional friction braking (non-hybrid or hybrid) Choosing the right method depends on traffic conditions (following vehicles) and how quickly you need to stop.

It shouldn't be that surprising. Race car drivers typically wear extremely thin-sole boots for similar reasons: for the highest level of tactile feedback from the vehicle, and to better finesse the pedals.

An example: approaching a fresh red traffic light that had no other indicators to predict the change (no pedestrian signal and no cars waiting on the cross street). If you brake lightly/moderately, you will cover the entire distance to the intersection and have no option but coming to a full stop.

But if you brake quite hard initially, you can potentially scrub enough speed and buy enough time to coast the remaining distance to the intersection at a low speed. With judgment and some luck, you'll arrive at a fresh green light and avoid a full stop.

Obviously, rapid deceleration isn't a safe option if there is following traffic.

Several web sites like EcoModder.com permit you to track and compare your fuel economy against other drivers, and some organize informal fuel economy challenges.

Hybrid festivals (e.g. hybridfest.com, greengrandprix.com) periodically run fuel efficiency rallies where you can hone your skills in competition with others in real time.

Note this isn't advocating high speed turns, where the cost of increased tire wear may outstrip fuel savings. Even at low speeds, choosing the "racing line" has benefits.

"Faking" a turn by signalling and moving into a turning lane (even though you intend to continue straight on) is one option.

Note: judgment and care is demanded so you don't mislead any driver into making an unwanted move as a result of your "miscommunication". You must be prepared to actually make the turn if your actions create a situation that would make it the safest option.

One method of gaining the attention of the driver behind is to move your vehicle very obviously to the extreme right of the lane you're traveling in when it's safe for the following vehicle to pass.

Adding a turn signal to the move or the 4-way flashers may be even more effective.

Of course, pulling completely off the roadway onto the shoulder to let following traffic by is also worthwhile, if you have the option.

EOC can be accomplished in non-hybrids as well simply by shifting to neutral and switching the key from "Run" to "Acc" (being careful not to switch to "Off" and cause the steering to lock). As soon as the engine stops, return the key to the "Run" position or else you will be in danger of locking out your steering and crashing. Also be careful to not steer at all while the key is off to prevent a lock up.

This technique is best suited to cars with manual steering and manual transmissions. (Dramatically increased steering effort may be required in some cars with power assist. Also, most vehicles with automatic transmissions are not designed to travel with the engine shut off; the transmission may be damaged).

In non-hybrids, EOC is considered an advanced technique and should not be attempted until the skill developed away from traffic. In addition, coasting with the engine off is illegal in some areas.

the best way to EOC is with a kill switch that shuts off the engine without removing the key, thereby eliminating the dangers of locking the steering wheel.

Note: When the engine is off the brake vacuum reserve is not recharged by the engine therefore drivers with the engine off will only get a few brake presses before the brakes no longer work.

In other words, you will back off the accelerator and lose speed (possibly also downshifting) as you climb, and gain that speed back on the descent.

It's far more efficient than pressing the accelerator more and more to maintain speed on the way up a hill and then releasing it down the other side.

DWL is how an efficiency minded person can greatly outperform cruise control in hilly terrain.

Obviously the ability to use this technique without adversely affecting other drivers depends on the traffic situation.

As well, fuel economy instrumentation is required to DWL/target drive to the maximum extent, though it can also be done using a vacuum gauge, and to a much lesser extent by the seat of the pants.

Yes, some people will cut into the space you create ahead of you. Deal with it.

Note that this may aggravate following drivers who can't absorb the big picture, and that must be taken into account.

You can plan even further ahead: don't turn the key until you know you can time the next traffic light down the street.

(the extent to which you might continue 'orbiting' depends on whether your engine is on/off and whether you're driving a manual or automatic. Also, it depends on traffic in the lot, obviously.)

Gravity can be a hindrance in parking as well. Avoid driving down into a parking "hole" which you must drive out of later. Even if you EOC into the hole, you'll face a net efficiency loss when you drive your cold vehicle up and out later.

Also note that reversing into a flow of traffic is riskier (and therefore much slower and less efficient) because you may not have a clear view until your vehicle's back end is well out of the space.

EG. if the posted speed is 30 and your car shifts into 3rd at 35, you may be able to achieve the 3rd gear shift, then reduce and hold 30 without causing a downshift.

Note: Some older cars which do not compensate the idle speed depending on engine load may use more fuel when in idle as the RPMs will go higher and therefore pump more fuel through the engine. Check your fuel usage meter to be sure.

Similarly, getting stranded in a ditch or snow drift because you set out in bad weather is a surefire way to waste fuel if you need to idle the car to stay warm while waiting for help.

Wheelspin is especially inefficient if your vehicle is equipped with brake assisted traction control.

An exception to this tip may be on "rutted" surfaces where water tends to pool in the ruts. In that case, driving on the ridges between the ruts offers less resistance.

Start to drive - under light loads - as soon as the engine is running smoothly (usually immediately). It's a more efficient way to warm the engine and entire drivetrain, including tires.

If you must park in the sun, placing a sunshade in your windshield will keep your car significantly cooler.

Other non-A/C options include ice vests and DIY ice water A/C units.

Driving at city speeds, you'll save fuel by using your flow through vents and opening windows.

At highway speeds, whether A/C is more or less efficient than opening windows will depend on the speed, your vehicle's aerodynamics and A/C design.

IE. avoid driving for any length of time beside a vehicle in the next lane. the more options you leave open for making a prompt lane change if one is needed, the afer and more efficient you'll be (if it means avoiding an unnecessary slowdown).

Leave enough space that you have time to choose other options (perhaps a lane change).

In addition, the greater your following distance, the better your forward visibility will be, which enables you to look well ahead and anticipate changes in the driving environment.

Being proactive will save fuel if it means you can avoid having to brake or stop unnecessarily.

In city driving you should know what's happening at least 10-15 seconds ahead. On the freeway, at least 30 seconds visual lead time is appropriate.

This is more important the faster and further you intend to go.

Meaning, if you think about spending energy as wisely in your car as you do when you ride, you should automatically become aware of several of the major tips on this list, such as:

a) Ensuring your tires are properly inflated & vehicle is in good mechanical condition, for reduced rolling & mechanical resistance.

b) Smart braking: you'll spend more distance coasting up to stops (you don't pedal madly towards stop signs and then jam on the binders, do you?)

c) You'll "drive with load" on hills (you don't usually power up hills trying to maintain your previous cruising speed, do you?)

d) You'll reduce speed (because cyclists are highly attuned to the relationship between aerodynamic drag and the BIG DOG energy consumed to travel at high speed).

Carry loads in the vehicle if possible.

If not, minimize towing speeds and adjust your technique to account for the extra momentum the trailer and its load will add.

Generally useful anywhere it will help you avoid the stop-and-go/idling in lines approaching the toll booth.