Does this advice apply to all cars?
In: 156
An object put in motion wants to stay in motion, right? If you are peddling a bicycle from a stop, you have to really stand on the pedal to get moving, then when you are moving it gets easier. The same with a car, it takes more effort to start moving which takes gas really dumping into the engine.
When you are coming up to a stop on your bike, if you kept peddling all the way to the finish line you will be expending energy all the way until you stop peddling. So you coast to a stop so your legs can rest. That is the same as an engine, it can not work to maintain speed and instead allow itself to slow down.
Braking essentially turns gasoline into heat and brake dust, and it just so happens you slow you down.
Think about every time you ride a bike. Do you try and keep rolling as much as possible, or do you hit the brakes hard, only to have to pedal hard again to get back up to speed?
For accelerating, its the same principle as a bike. If you gradually come up to speed, you have time to use your gears efficiently and keep your cadence (pedaling speed) low. But when you are trying to get up to speed fast, you are more likely to pedal your legs really quickly, which does deliver a lot more power, but it is a lot more draining.
In a car, you are burning more fuel in the engine if you revv it really high, but it does get you up to speed quickly. By being more gradual, you are allowing the car to shift through the gears for the best advantage.
For accelerating:
When you want to accelerate your car’s brain has to make many decisions, like when to change gears, how much fuel to use, etc. When you floor the pedal, you’re telling your car “forget fuel, I wanna go FAST!” And your car zooms off
If you press the pedal softer, your car goes “Oh, he doesn’t wanna go fast. Here lemme save him some more fuel since I can”, and that’s why you use less fuel.
As for braking, think of a bicycle. If you brake hard on a bicycle, you never “coast”, which is time you’re not pedaling. Same thing for cars, by braking slower, you’re actually breaking **earlier**, which means you coast more and save fuel.
A lot of answers, none technically correct.
Vehicles are most efficient (by design) when under a comfortable acceleration between a set RPM range, pushing that same engine outside of it’s efficiency zone (hard acceleration, to high or low RPM, wide open throttle etc) will have the engine performing the same task but at a greatly reduced efficiency, resulting in more fuel being burnt for the same result (speed).
Moving a mass to a certain speed requires the same amount of energy regardless of the amount of time taken to do it. The variable for internal combustion engines is the efficiency of converting fuel into usable energy.
Accelerating slowly in cars with automatic transmission or CVTs allows them to shift to a higher gear (or lower gear reduction) for more of the time and distance they are accelerating compared to accelerating fast. Higher gears are better for fuel efficiency because the engine spins slower to make the car go the same speed than in lower gears. Just like how riding your bike in higher gears uses less energy per mile than lower gears.
The most efficient way to slow down in modern cars is to not touch the brake or accelerator pedal at all and let the car slow down on its own. This is called engine braking and modern cars cut of the flow of fuel to the engine entirely while you’re doing it. Manual transmission cars can coast in neutral as well, but the engine will still consume fuel just to maintain idling RPM. A lot of driving situations keep you from slowing down like this. However, coasting in neutral, engine braking or gentle braking still improve fuel economy because, if you’re decelerating very slowly like this, you probably didn’t use a lot of fuel getting up to an excessive speed in the first place. Gentle braking or coasting necessarily means you’re lowering your fuel consumption to get up to speed before you ever start slowing down. And the next traffic light might change or the cars ahead of you might start moving again if you’re going slower compared to when you’re going faster. So you need less fuel to get back up to speed in these situations.
Braking slowly – feathering the brakes – helps them last longer. I had a friend who drove me crazy when I’d ride with (she was elderly). She would ride the brakes. Her husband told me they had to have the brakes replaced on a newish model about every 18 months.
I don’t think being easy on brakes saves any gas but it certainly saves money by not needing brakes replaced sooner than they should be.
The difference between slow acceleration and rapid acceleration is that the acceleration (a) is different. The magnitude of the acceleration is related to the traction force (F) and the mass (m). F=m*a, the greater the acceleration, the greater the traction force required. The work of the car running (W) = F*s (distance), so the greater the traction, the more work, and the more fuel it consumes. There are other factors that are not considered
Specific to hybrids…
When you’re not pressing the accelerator, your electric engine is actually slightly braking, and pressing the brake pedal usually increases this. When your electric engine is braking, it’s more or less running in reverse. So instead of draining the battery to go, it’s “borrowing” some “go” for later and storing it back in the battery. Gently braking gives the optimal charging rate and wears your actual friction brakes much, much less.
As for slow, steady acceleration, the slower you accelerate, the more of that acceleration your electric engine can do. Accelerate too quickly and you’ll either drain the battery very quickly (at which point you’ll need the gas engine to help it recover) or you’ll have the gas engine kick in to pick up more of the slack.
Learning to use the cars own weight move it naturally as opposed to engine power is a useful skill kind of a like throwing a stone that skips your initial throw launched it but it’s own weight Carries it to some degree
I think it helps to flip it. If you consider that it is braking, not accelerating, that causes overconsumption, you can’t go wrong.
An ideal scenario for high efficiency is a straight line from start to finish, you accelerate in the beginning, find your happy speed, and let go of the gas pedal when destination is near. If you time it right, you’ll come to a stop without need ing to brake.
If keep the foot on the gas pedal too long, you’ll need to use the brake. Braking doesn’t use gas per se, but it’s a symptom of you having accelerated too long. Which does use gas.
If you can drive with minimal use of the brakes, you’re saving gas. By thinking ahead and stoping acceleration earlier than a braker.
It’s fun too. Keeps you focused. Makes you a fiend to brakers, but hey, everyone is someone’s fiend.
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