Help with preparing an ecodriving booth

[Weather Spotter]

You tried, most people have there heads in the sand. It will take something major to shock them into thinking.

[Piwoslaw]

Originally Posted by Piwoslaw

We also made two quizzes, one was about the public transport system (How many subway stations in Warsaw?, How many bus lines?, How much more space does it take to carry X people in cars than in a bus?, etc.), the other about ecodriving. If I find a minute, I'll translate and post it for others to use. (If I don't post it within a month, then someone please bug me about it.)

And here it is:

1. By how much does air drag increase when after accelerating from 50 km/h to 70 km/h?
   a) 20%
   b) 50%
   c) 100%
   d) 200%
   
   Answer: c) 100%. Drag increases with the square of speed, so a 40% increase in speed doubles the air resistance, while going twice as fast - increases drag fourfold.
   
2. Which braking method uses less fuel?
   a) Accelerating until the last moment, then sudden hard braking.
   b) Coasting in neutral, then lightly braking.
   c) Engine braking (gear reduction if necessary).
   
   Answer: c) Engine braking. Engines with fuel injection cut off fuel when engine braking, allowing the car to travel a certain distance "for free". Coasting in neutral still requires fuel to keep the engine idling.
   
3. An underinflated tire has less rolling resistance than a well inflated tire.
   a) True
   b) False
   
   Answer: b) False. Higher pressure = Lower RR.
   
4. An underinflated tire has less grip than a well inflated tire.
   a) True
   b) False
   
   Answer: a) True. In spite of what most people believe, research has shown that underinflated tires give a longer braking distance, reducing safety.
   
5. Which acceleration method uses less fuel?
   a) Slowly building up speed.
   b) Quick acceleration with upshifting as soon as possible.
   c) Quick acceleration with high rpms.
   
   Answer: b) Quick acceleration with upshifting as soon as possible. You should get up to speed as quickly as possible, but without exceeding 2000 rpm (diesel) or 2500 rpm (petrol). Throttle should be at about 75%-80%.
   
6. How much fuel does an engine consume when idling?
   a) Idling doesn't consume fuel.
   b) About 0.1 liter per hour.
   c) From 0.5 to 1 liter per hour.
   
   Answer: c) From 0.5 to 1 liter per hour. This depends on the size and type of engine, and on accessories that put a load on the engine (lights, wipers, radio, heated seats, window defogger, etc.).
   
7. After starting a cold engine:
   a) You should wait 5-10 minutes until the engine warms up.
   b) You should immediately start driving, but without "flooring it".
   c) You should immediately start driving, putting a load on it to help it warm up faster.
   
   Answer: b) You should immediately start driving, but without "flooring it". An idling engine takes longer to warm up, so parts are moving without proper lubrication for a longer time. Hard acceleration at high rpms also causes accelerated wearing of parts.
   
8. Driving with a roof rack increases fuel consumption by:
   a) Up to 10%
   b) Up to 20%
   c) Up to 30%
   d) Over 30%
   
   Answer: d) Over 30%. Even an empty roof rack or roof rails can increase fc by as much as 5%-15%.
   
9. Below what speed does air drag stop effecting fuel consumption?
   a) 100 km/h
   b) 70 km/h
   c) 50 km/h
   d) 30 km/h
   
   Answer: None of the above This is a trick question. Air drag causes resistance at any speed, as anyone who tries to ride a bike at 40-50 km/h for a longer time will find out.

[tumnasgt]

Originally Posted by Piwoslaw

And here it is:
An underinflated tire has less rolling resistance than a well inflated tire.
a) True
b) False

Answer: a) True. Higher pressure = Lower RR.

I think you have your words backwards there, it should be more for an underinflated tire.

[Piwoslaw]

Originally Posted by tumnasgt

I think you have your words backwards there, it should be more for an underinflated tire.

Thanks for catching that
I was pretty tired yesterday evening...

[bestclimb]

#5

...Quick acceleration with upshifting as soon as possible. You should get up to speed as quickly as possible...

Implies full throttle.

[Piwoslaw]

Originally Posted by bestclimb

#5

...Quick acceleration with upshifting as soon as possible. You should get up to speed as quickly as possible...

Implies full throttle.

OK, OK, I've added 80% throttle.

[euromodder]

Originally Posted by Piwoslaw

[*]Which braking method uses less fuel?
a) Accelerating until the last moment, then sudden hard braking.
b) Coasting in neutral, then lightly braking.
c) Engine braking (gear reduction if necessary).

Answer: c) Engine braking. Engines with fuel injection cut off fuel when engine braking, allowing the car to travel a certain distance "for free". Coasting in neutral still requires fuel to keep the engine idling.

Well, I disagree

Coasting gets you a lot further than using DFCO.
The difference in distance travelled would be covered at constant-speed fuel consumption, which will be a lot higher than the idle FC during coasting.
Both techniques may require a dab on the brakes anyway to come to a full stop - but that's when coasting with the engine on is getting less efficient.


I was using DFCO quite a lot before joining EM, only twice doing better than 5L/100km (47mpg).
Coasting engine-on has had a significant impact on my FE since : I think it's the main reason I can regularly get my FC below 5L/100km (or above 47mpg) now.

I had driven @ 100 kph before, without much effect on FE.
Actually, I still see little difference between 100 and 105 kph in FC as the engine seems to be running in a less efficient rpm / load situation at 100kph.
I gain from not accelerating the extra 5kph though.

[tumnasgt]

I think he was meaning if you have the same amount of space to stop in.

I agree that DFCO isn't as good as coasting if distance isn't such a problem, I have a driving test coming up, and I found out that if I coast I will fail, so I'm trying to unlearn the habit until after the test. My last two tanks have suffered as a result, my last being only 31MPG instead of the 33MPG I was getting when coasting wherever possible.