One Litre of Petrol Idle for How Long?

[Thaiyotakamli]

Lets say car average petrol fc is 10km/l, how much time of idling in minutes will consume one litre of petrol?

[Vega]

not sure if this piece of info will help. I know of a golf that idle for about 2 hrs and it consumes about 1/4 tank of fuel.

[Zippaboy]

haha i ever idle in an altis overnight, it dropped like 2-3 bars only.....

[Tianmo]

Lets say car average petrol fc is 10km/l, how much time of idling in minutes will consume one litre of petrol?

 

I think sld be cheaper than the cheapest hotel........... [laugh]

[F355]

We get funny questions at MCF but I'll give it a try anyway .

 

 

Assumptions :-

1) The engine is naturally aspirated and the amount of fuel consumed is directly proportional to the rpm

2) The vehicle on average is travelling at 100 km/h with engine speed 2500 rpm to achive 10km / l

3) The engine is 700 rpm at idle

 

At 100 km/h , it takes 6 minutes to cover 10km, with 1L of fuel .

 

So if 1L can supply 2500rpm x 6 mins , at idling 700 rpm , it should last

 

2500/700 x 6 = 21 mins .

 

 

 

1L 20mins

Full tank 50 L shd be able to last 1000 mins or 16.6 hrs

 

 

 

Edited November 22, 2014 by F355

[Cephas]

We get funny questions at MCF but I'll give it a try anyway .

 

 

Assumptions :-

1) The engine is naturally aspirated and the amount of fuel consumed is directly proportional to the rpm

2) The vehicle on average is travelling at 100 km/h with engine speed 2500 rpm to achive 10km / l

3) The engine is 700 rpm at idle

 

At 100 km/h , it takes 6 minutes to cover 10km, with 1L of fuel .

 

So if 1L can supply 2500rpm x 6 mins , at idling 700 rpm , it should last

 

2500/700 x 6 = 21 mins .

 

 

 

1L 20mins

Full tank 50 L shd be able to last 1000 mins or 16.6 hrs

 

 

 

Sound like psle question...lol

[Thaiyotakamli]

We get funny questions at MCF but I'll give it a try anyway .

 

 

Assumptions :-

1) The engine is naturally aspirated and the amount of fuel consumed is directly proportional to the rpm

2) The vehicle on average is travelling at 100 km/h with engine speed 2500 rpm to achive 10km / l

3) The engine is 700 rpm at idle

 

At 100 km/h , it takes 6 minutes to cover 10km, with 1L of fuel .

 

So if 1L can supply 2500rpm x 6 mins , at idling 700 rpm , it should last

 

2500/700 x 6 = 21 mins .

 

 

 

1L 20mins

Full tank 50 L shd be able to last 1000 mins or 16.6 hrs

 

 

 

Thanks bro! It gives me a better idea of my car FC when idle

 

I think sld be cheaper than the cheapest hotel........... [laugh]

Yes especially those who count hourly rate haha

haha i ever idle in an altis overnight, it dropped like 2-3 bars only.....

Sleep in ecp is it?

 

It seems cheaper than staying overnight in a hotel if homeless

not sure if this piece of info will help. I know of a golf that idle for about 2 hrs and it consumes about 1/4 tank of fuel.

Thats alot le

[Steptronic]

Before 1 litre is finished, NEA officials will be there to book! This 1 litre idling could be as costly as 5k SGD!

[F355]

Thanks bro! It gives me a better idea of my car FC when idle

 

 

 

Pls take my estimations with a pinch of salt . They are very very rough estimates only , and the assumptions and derivations may not even be valid .

 

It does not take into account of the fact that more fuel is actually required when travelling ( ie getting work done ) ; against idling , overcoming wind resistance and friction etc etc etc .

 

They most accurate method is to fill up your tank , let it idle for say 6 hrs ( the longer it idles, the lesser the margin of error ) , then fill her up again and see how many litres is being consumed .

[Thaiyotakamli]

Before 1 litre is finished, NEA officials will be there to book! This 1 litre idling could be as costly as 5k SGD!

The fine is 5k? Wow that one i dunno

[Detach8]

I have measured before with a computer, and it takes approximately 1L of fuel per hour. Some cars also shows L/h on the computer when you are stationary (as opposed to 0km/l)

We get funny questions at MCF but I'll give it a try anyway .

 

 

Assumptions :-

1) The engine is naturally aspirated and the amount of fuel consumed is directly proportional to the rpm

2) The vehicle on average is travelling at 100 km/h with engine speed 2500 rpm to achive 10km / l

3) The engine is 700 rpm at idle

 

At 100 km/h , it takes 6 minutes to cover 10km, with 1L of fuel .

 

So if 1L can supply 2500rpm x 6 mins , at idling 700 rpm , it should last

 

2500/700 x 6 = 21 mins .

 

 

 

1L 20mins

Full tank 50 L shd be able to last 1000 mins or 16.6 hrs

 

 

 

 

LOL nice work! (and hard work)

But modern engines lean burn during idle so it is likely taking less fuel than driving under load at 2,500 rpms.

[Kklee]

Lets say car average petrol fc is 10km/l, how much time of idling in minutes will consume one litre of petrol?

 

Chevrolet Optra 1.6A with FC around 10km/L :-

1.5 LPH in N

1.9 LPH in D

 

P.S.

Extensive idling may cause dirty throttle body and reduce service life engine oil.

Consider an oil catch tank.

Engine is most efficient and clean while being driven.

 

Edited November 22, 2014 by Kklee

[Camrysfa]

The fine is 5k? Wow that one i dunno

 

haha, you may just get warning first,....

 

http://www.straitstimes.com/news/singapore/environment/story/warnings-issued-14-motorists-caught-leaving-vehicle-engines-idling-

SINGAPORE - Warning letters were issued on Wednesday to 14 motorists who had left their vehicle engines idling while stationary in a three-hour enforcement exercise by the National Environment Agency (NEA) in Ang Mo Kio. NEA also distributed pamphlets and anti-idling car decals to 236 motorists, as part of the exercise to promote compliance with anti-idling regulations, which NEA officers had found many motorists to be unaware of.

Those who left their engines on were workers loading or unloading goods, taxi drivers waiting for customers, parents waiting for school-going children, or simply drivers taking a break in their vehicles.

Under Environmental Protection and Management (Vehicular Emissions) regulations, it is an offence to leave the engine of a motor vehicle running when it is stationary for reasons other than traffic conditions. Those breaching the law can be fined up to $5,000

In a statement, the NEA urged the public to turn off their engines after parking for better air quality and public health.

[Vhtfhwlego]

If one really want to know how idle consumption is,

Very close estimation will be:

 

1) Fill the tank to the brim

2) Move slowly to the carwash behind (auto cars, don't accelerate. Manual cars, slip into 1st gear and let go clutch and don't accelerate as well).

3) idle while washing.

4) go back to pump.

 

Use the time at 2-4 and fuel use for the 2nd top up.

[Thaiyotakamli]

But calculations will be different if u drive a hybrid

[Ben5266]

We get funny questions at MCF but I'll give it a try anyway .

 

 

Assumptions :-

1) The engine is naturally aspirated and the amount of fuel consumed is directly proportional to the rpm

2) The vehicle on average is travelling at 100 km/h with engine speed 2500 rpm to achive 10km / l

3) The engine is 700 rpm at idle

 

At 100 km/h , it takes 6 minutes to cover 10km, with 1L of fuel .

 

So if 1L can supply 2500rpm x 6 mins , at idling 700 rpm , it should last

 

2500/700 x 6 = 21 mins .

 

 

 

1L 20mins

Full tank 50 L shd be able to last 1000 mins or 16.6 hrs

 

 

 

good idea.

But you did not factor in resistant of wind and tires.

At 100kmph, some fuel is used to overcome the wind.

So perhaps the answer is 50% more than your calculation. Depending on the aerodynamic of the car.

[Ben5266]

If one really want to know how idle consumption is,

Very close estimation will be:

 

1) Fill the tank to the brim

2) Move slowly to the carwash behind (auto cars, don't accelerate. Manual cars, slip into 1st gear and let go clutch and don't accelerate as well).

3) idle while washing.

4) go back to pump.

 

Use the time at 2-4 and fuel use for the 2nd top up.

better to go JB on long weekend. Top up and reset meter before heading to check point. At least you are not wasting petrol for this test.

[Paddie]

For some cars, the instant fuel consumption reading changes from l/100km or km/l when moving, to litres/hour when idling. Usually it's around 0.8-1.2 litres per hour of idling so if you have a 60 litre tank, you can idle for 2.5 days.