A higher fuel economy can be achieved by accelerating up to a speed and then coasting.
BHPian toyotafanboi recently shared this with other enthusiasts.
Hypermiling refers to a set of driving techniques used to extract the most miles per unit of fuel from your car. Achieving the highest possible fuel economy is all about the conservation of momentum. Here are some ways in which you can save some gas and be a more efficient driver.
- Remove unnecessary weight from your car. This is something simple but can have a huge impact on your fuel consumption.
- In terms of fuel consumption at cruising speed, AC on >/= AC off windows down (due to increased drag) > AC off windows up
- On highways, try to maintain a steady speed of 80-90 km/h. Fuel economy drops significantly at higher speeds (more info here)
- Contrary to popular belief, shifting to a higher gear as early as possible does not necessarily give better fuel economy. An important concept to understand here is BSFC (Brake Specific Fuel Consumption). Simply put, BSFC is the amount of fuel consumed per unit of power produced. Although less fuel is consumed at a lower rpm (e.g. 2000 rpm vs 2500 rpm), when accelerating, you would ideally want the engine at an rpm range where the BSFC is lowest. This rpm range is called the sweet spot and can be anywhere between 2000 and 3000 rpm in most cars.
Side note: I came across conflicting information online whether full throttle or part throttle achieves better efficiency when accelerating. Maybe someone more knowledgeable can shed some light here.
- As a general rule, use the ABC pedals as little as possible and try to conserve the car’s momentum. For example, when you see a red traffic light ahead, let off the accelerator and coast in gear. It requires more energy to move a car from a standstill than one in motion. However, in emergency situations remember safety always comes first.
- Almost all modern cars have a feature called deceleration fuel cut off (DFCO) which essentially cuts off fuel when decelerating in gear above a certain engine rpm. This means when going downhill, staying in gear not only provides engine braking but uses virtually no fuel (when off the accelerator).
- The above feature (DFCO) also means, a higher fuel economy can be achieved by accelerating up to a speed and then coasting, instead of keeping the accelerator depressed all the time. (e.g. accelerate to 100 km/h and coast till 80 km/h, then repeat). This technique is called Pulse and Glide.
Are there any hypermiling techniques you guys use that are not mentioned here? Please share them below.
Here’s what BHPian adisan had to say on the matter:
Thanks for sharing.
When going uphill, maintain the same level of A pedal input. Downshift if needed. Increasing the A pedal input to maintain the same speed as before decreases FE.
Here’s what BHPianIndigoXLGrandDi had to say on the matter:
Does Cruise Control decrease FE?
Suppose I have set CC to 80km/h and driving on a downslope. The speed of the car would try to increase over 80km/h due to downslope but CC will apply the brake and try to maintain the speed at 80km/h. So fuel gets wasted.
The opposite happens for an upward Slope. The speed of the car would try to fall below 80km/h due to upslope but CC will increase and try to maintain the speed at 80km/h. So again fuel gets wasted as the car tries to accelerate in the higher gear.
Experts, am I wrong here?
Here’s what BHPian Turbohead had to say on the matter:
I have one regarding safety:
I’ve tried driving to get some really high mileage for fun. In the pursuit of extracting every possible meter from every drop, I noticed that I tried to avoid braking as much as possible in order to maintain the momentum. I soon realised that it was as dangerous as driving over the speed limit after putting myself into a number of incidents for which I would usually try to brake in advance.
Long story short, don’t get carried away with mileage or adrenaline cause you can lose way more than you gain.
Keyword: Improving Fuel efficiency on any car: Hypermiling techniques explained