Why braking affects fuel economy for beginners along with tips

[jedi_sol]

Thanks for the tips , they are a little more detailed than the 100 efficiency hypermiling techniques sticky.

[Prophecy99]

what's the best way to brake?

all of us hear understand the basic coasting to up coming red lights/traffic but what is better - waiting to the last second to brake really hard once and continue rolling or more earlier on tap the breaks moderately 1 or 2 times and more gradually transition into re-accelerating?

In other words I don't like using brakes to slow down which is the biggest point here but when I use them I like to use them aggressively. Is this eco-friendly?

[jedi_sol]

Per the 100+ hypermiling techniques sticky, there is a "braking hierarchy":

BRAKE TIPS
44) The most efficient way to slow down
When you *have* to slow down, here's an approximate heirarchy of methods, from best to worst.

1) coasting in neutral, engine off (ie. roll to a stop);
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.


45) Conserve momentum: avoid stopping
Avoid coming to a complete stop whenever possible (and when safe and legal of course). It takes much less energy to accelerate a vehicle when it's already traveling just a few kilometers per hour than it does from a complete stop.

47) "Drive without brakes" (DWB)
Minimize use of the brake pedal. Each time you press it, you're effectively converting gasoline into brake dust and heat.

Driving as if you have no brakes will cause you to do two things: 1) reduces 'excessive' acceleration, and, 2) extends the amount of time you spend coasting down to stops and turns.

Obviously you have to balance use of this technique against traffic conditions so as not to adversely affect other drivers.

See the Ecomodder Blog for more information on DWB.

Therefore, in your situation, it all really depends on timing. Ultimately, the goal is to conserve momentum and to avoid coming to a complete stop.

If you have the room to coast to a stop at the stopsign, then use methods 1 or 2.

If you're going too fast and need to scrub off some speed...but still able to coast thru the light...then use method 5.

[Diesel_Dave]

Originally Posted by Prophecy99

what's the best way to brake?

all of us hear understand the basic coasting to up coming red lights/traffic but what is better - waiting to the last second to brake really hard once and continue rolling or more earlier on tap the breaks moderately 1 or 2 times and more gradually transition into re-accelerating?

In other words I don't like using brakes to slow down which is the biggest point here but when I use them I like to use them aggressively. Is this eco-friendly?

After you've begun the glide, the goal is to pass though the red light with the greatest possible speed. As far as braking early vs late it's a tradeoff you have to make. The advantage of braking early is there's a greater likelyhood that you won't have to use the brakes as aggressively later--braking early gives more time for the red light to change/traffic to move. The advantage of waiting to later is that the light may change eariler than expected and you may avoid having to use the brakes at all.

So it's a bit of an art. You can help yourself somewhat with different "hints" (looking ahead, watching cross traffic, watching walk signs, etc.) but there's still some luck involved. All you can do it try to maximize you chances.

[Fat Charlie]

[briank]

45) Conserve momentum: avoid stopping
Avoid coming to a complete stop whenever possible (and when safe and legal of course). It takes much less energy to accelerate a vehicle when it's already traveling just a few kilometers per hour than it does from a complete stop.

While the title of 45) is good, the explanation is confusing. I maintain it doesn't take much less energy to accelerate a vehicle when it's already traveling compared to when it's stopped.

It takes about the same energy to accelerate a car from 60 to 61 mph as it does to accelerate a car from 0 to 10 mph.

[NeilBlanchard]

It takes a lot less energy to accelerate from ~15mph to XYmph than it does to accelerate from 0mph to XYmph. That is the situation that the tip is about.

[jedi_sol]

Originally Posted by briank

45) While the title of 45) is good, the explanation is confusing. I maintain it doesn't take much less energy to accelerate a vehicle when it's already traveling compared to when it's stopped.

It takes about the same energy to accelerate a car from 60 to 61 mph as it does to accelerate a car from 0 to 10 mph.

thats the point...even though it doesnt take much less energy to go from 60-61 vs 0-10...it still takes less

[101Volts]

Originally Posted by Old Mechanic

I just walk in an order my food, eat it, and drive away. I also will slow down more rapidly when approaching a light to see if I can avoid stopping altogether. On a good day I will only have to stop for 4-6 of the 46 lights on my usual route. Try to time it so you go through the intersection at the highest speed possible, within legal limits. In some cases that means stopping, or slowing down fairly rapidly. Other times you can coast through the light just as it changes and pass all the dummies that blasted, by you, to the light when it was red.

regards
Mech

I'll add one true story from 2012 or 2011; I was going at just the speed limit of 45 MPH or so according to the 1997 Plymouth Voyager (Extended)'s speedometer about six miles away from home and then one or two people in a Red Corvette passed the van but I kept going the speed limit. Then about 2.3 miles later I caught up to them closely at the very first red light in town; There was only one car between the van I drove and the corvette. I'll let the reader think of that, I'm not about to add any "How much time they saved VS how much fuel they used" comments.

[basjoos]

When driving a manual, when you have to slip the clutch to get moving from a standstill, you are wasting a lot of energy. So when driving a manual, when feasible try to keep your speed from ever getting below the speed your car travels at when in 1st gear with the engine idling. I consider both brake linings and clutch linings to be consumables and try to avoid using them whenever possible.