fuel economy

Bpmull

Thought this thread would be a good one to set up with the price of fuel recently. How to improve your cars mpg. Any advice would be appreciated and hopefully this thread will help those who know little about cars but just want to improve their cars efficiency. I didn't really care much about mpg until i got my first car a few weeks back now its a big concern with the cost of filling up. so any advice comments would be appreciated. ill start of with the obvious ones

Tyre pressure: ensure your cars tires are at the correct pressure as just a few psi can make a big difference to mpg.

weight: do not carry excess weight which is not necessary in your car as the extra weight puts more pressure on the engine thus increases fuel consumption.

Air con: don't use air con unless it is really hot as it reduces mpg.

service: service your car on time as it can only but help mpg and also help keep your car mechanically sound.

please add advice to these as this is only the start and there is so many other ways.

Francie Barrett

Drive slower?

MidlandsM

Walk....... lol

Indricotherium

Construct a nosecone from fibreglass and attach it to the front of your car to increase aerodynamic efficiency.

Same re vortex distorters on rear of car.

Indricotherium

Fill car with many many helium filled balloons, but not in a way that would effect safe opperation of the vehicle, thus reducing its weight and increasing fuel efficiency.

Hay_man

Bpmull wrote: »

Air con: don't use air con unless it is really hot as it reduces mpg.

.

Interesting, what about leaving it at 20 degrees or so ? does it still effect fuel economy then as much?

Kenny Logins

If you tip a load of gravel into your tank it'll cost less next time you fill up with petrol.

You're welcome.

sheehan12

use green diesel:pac:

07Lapierre

Empty the Boot! (Don't carry around any extra weight)

Don't drive with the widows open (especially if the aircon is on)


How much fuel you save? not much i suspect.

Indricotherium

Don't carry any excess weight at all in your car.

To do this ensure you only fill the tank with the absolute minimum of fuel (usually 2 litres) when at a petrol station.

Indricotherium

07Lapierre wrote: »

How much fuel you save? not much i suspect.

This is true of almost every tip that will appear on this thread apart from drive slower and drive less.

shedweller

Indricotherium wrote: »

07Lapierre wrote: »

How much fuel you save? not much i suspect.

This is true of almost every tip that will appear on this thread apart from drive slower and drive less.

And we all know the boards response to people driving slower......

Trampas

i find turning off the engine on downhills helps greatly

kirving

Never coast, as your engine will use fuel to keep it ticking over.

For Forks Sake

shedweller wrote: »

And we all know the boards response to people driving slower......

colm_mcm

Kevin Irving wrote: »

Never coast, as your engine will use fuel to keep it ticking over.

Ah yes, but your engine will slow your car down so you'll need to accelerate sooner.

Coasting is bad anyway but I'm not sure it actually uses more fuel.

johndaman66

A cold engine uses more fuel than one which is at optimum operating temperature...much much more in my experience. If you have a number of journies to make attempt to plan them in close succession where permissable

Jimbob 83

No fat chicks allowed

Rich11

Bpmull wrote: »

Air con: don't use air con unless it is really hot as it reduces mpg.

I heard somewhere that at certain speeds it better to have the air con on than the windows open cause with the windows open its increasing drag

Where To

Treat the pedals like you're playing footsie with Paris Hilton.

arleitiss

Would these ideas work to help and save fuel?

1) When driving at like 50 km/h be in 5th gear even though revs are only about 1000-1300?
2) When you are on hill or flat road and road is quite empty increase bit of speed and put into neutral and just use brakes to control turns? (I know this may sound silly and extreme but I read that somewhere on internet )
3) Does open windows really increase fuel consumption?
4) Standing in traffic in 1st gear rather than neutral, does it consume fuel?

Btw does every kilo(kg) in car load affects fuel? or would it come only to 10-50 kg that affects consumption and performance?

Rich11

arleitiss wrote: »

Would these ideas work to help and save fuel?

1) When driving at like 50 km/h be in 5th gear even though revs are only about 1000-1300?
2) When you are on hill or flat road and road is quite empty increase bit of speed and put into neutral and just use brakes to control turns? (I know this may sound silly and extreme but I read that somewhere on internet )
3) Does open windows really increase fuel consumption?
4) Standing in traffic in 1st gear rather than neutral, does it consume fuel?

Btw does every kilo(kg) in car load affects fuel? or would it come only to 10-50 kg that affects consumption and performance?

arleitiss wrote: »

Would these ideas work to help and save fuel?

1) When driving at like 50 km/h be in 5th gear even though revs are only about 1000-1300?
2) When you are on hill or flat road and road is quite empty increase bit of speed and put into neutral and just use brakes to control turns? (I know this may sound silly and extreme but I read that somewhere on internet )
3) Does open windows really increase fuel consumption?
4) Standing in traffic in 1st gear rather than neutral, does it consume fuel?

1) i normally dont go into 5th till 60/70km/h, at 50km/h in 5th your car is almost laboring so using more fuel
2)no, if your going down a hill your car will use more fuel in neutral than it will in gear, when your car is in neutral and going down a hill fuel is being pumped into the engine to keep it running, where as if its in gear and your not pressing the gas pedal, its using practally none.
3)

Rich11 wrote: »

I heard somewhere that at certain speeds it better to have the air con on than the windows open cause with the windows open its increasing drag

4) i would'nt think so, i cant see how it would

Jimbob 83

Coasting doesn't save fuel it just breaks components

PaulKK

arleitiss wrote: »

1) When driving at like 50 km/h be in 5th gear even though revs are only about 1000-1300?

IMO that would be labouring the engine and a sure way to wear our your DMF.

My car has a current MPG readout and the most efficient gear to be in is always when the revs are between 1.7k and 2.2k (diesel).

arleitiss wrote: »

2) When you are on hill or flat road and road is quite empty increase bit of speed and put into neutral and just use brakes to control turns? (I know this may sound silly and extreme but I read that somewhere on internet )

Car in neutral when moving uses fuel, car in gear and your foot off the pedal uses no fuel when moving at speed.

arleitiss wrote: »

3) Does open windows really increase fuel consumption?

Yes, above quite slow speeds obviously, you are increasing drag.

arleitiss wrote: »

4) Standing in traffic in 1st gear rather than neutral, does it consume fuel?

No more than being in neutral, but you are unnecessarily wearing out your clutch.

L1011

Bpmull wrote: »

Air con: don't use air con unless it is really hot as it reduces mpg.

I'd rather use it regularly and avoid having to get it extensively serviced due to damage/mould from not using it enough... aircon is not designed to stay off for huge periods.

magicbastarder

Rich11 wrote: »

I heard somewhere that at certain speeds it better to have the air con on than the windows open cause with the windows open its increasing drag

probably true at high speed, at a point where you wouldn't have the windows open anyway.

Kenny Logins

I think the only way to really improve your MPG is to change car.

magicbastarder

arleitiss wrote: »

4) Standing in traffic in 1st gear rather than neutral, does it consume fuel?

you mean holding the car in place by taking a tiny bit of pressure off the clutch, or actually sitting there in gear, but with the clutch fully depressed?

Bpmull

johndaman66 wrote: »

A cold engine uses more fuel than one which is at optimum operating temperature...much much more in my experience. If you have a number of journies to make attempt to plan them in close succession where permissable

That's a good one engines use way more fuel until they reach operating temperature.

magicbastarder

i'm getting about 9 to 10c on petrol per kilometre at the moment, 1.4 octavia - a good deal of that is country roads, though.

one of the main factors in increasing fuel efficiency is anticipation - you see a lot of people burning petrol in accelerating up to a hard bend or red lights, rather than simply taking their foot off the accelerator and letting momentum do the work.

Bpmull

magicbastarder wrote: »

i'm getting about 9 to 10c on petrol per kilometre at the moment, 1.4 octavia - a good deal of that is country roads, though.

one of the main factors in increasing fuel efficiency is anticipation - you see a lot of people burning petrol in accelerating up to a hard bend or red lights, rather than simply taking their foot off the accelerator and letting momentum do the work.

That's true as dramatically accelerating and breaking reduces fuel efficiency were as letting a car roll up to the lights In gear using the brake gradually uses next to no fuel. Btw the above is the correct way to do it some people think coasting saves fuel as their revs drop completely wrong. When your car is in neutral it is idleing which uses fuel. When it is in gear moving to the stop with no acceleration it uses no fuel.

07Lapierre

Bpmull wrote: »

That's true as dramatically accelerating and breaking reduces fuel efficiency were as letting a car roll up to the lights In gear using the brake gradually uses next to no fuel. Btw the above is the correct way to do it some people think coasting saves fuel as their revs drop completely wrong. When your car is in neutral it is idleing which uses fuel. When it is in gear moving to the stop with no acceleration it uses no fuel.

Correct me if I'm wrong, But as long as the engine is running, its using fuel? small amounts maybe, but its using fuel. If the engine was not getting any fuel, it would stop! So i fail to see how a car is in gear and moving with no acceleration is not using any fuel (unless the engine is turned off).

Jimbob 83

Jimbob 83 wrote: »

Coasting doesn't save fuel it just breaks components

..... What components?

Bpmull

07Lapierre wrote: »

Correct me if I'm wrong, But as long as the engine is running, its using fuel? small amounts maybe, but its using fuel. If the engine was not getting any fuel, it would stop! So i fail to see how a car is in gear and moving with no acceleration is not using any fuel (unless the engine is turned off).

I could be wrong but when the car is in gear and there is no acceleration then the turning wheels keep the engine turning revs going and uses no fuel as the momentum of the wheels. Keep the cylinders turning. When coasting the engine it idleing completely disconnected from the moving wheels and uses fuel. That's how I understood it but I could be 100 miles off never really looked into it.

magicbastarder

07Lapierre wrote: »

Correct me if I'm wrong, But as long as the engine is running, its using fuel? small amounts maybe, but its using fuel.

fuel is used to turn the engine, generally speaking - but if the car is in gear and moving and you take your foot off the pedal, the momentum of the car turning the wheels is turning the engine, and the fuel consumption drops to zero; i.e. the car does not need the fuel to turn the engine.
obviously, you don't want to do this if the revs being generated drop too low.

driver02

Apparently having your heated rear window on burns 5% more on fuel was given the reason once but forgot it. it's true though i'm sure

magicbastarder

i would suspect the headlights use a lot more electricity than the rear windscreen heater - they generate more heat (and light).

Kenny Logins

driver02 wrote: »

Apparently having your heated rear window on burns 5% more on fuel was given the reason once but forgot it. it's true though i'm sure

Any electrical components in use in the car will create a magnetic load on the alternator, but I'm not sure it would be that high.

magicbastarder

yep, think about the power required to heat a small area of glass by a few degrees, compared to the power required to accelerate a ton or two of metal to 50mph.

BrianD3

Read the road, think ahead and anticipate in order to minimise use of brakes eg when approaching bends. Doing this is one reason why I get ~65 mpg from a Megane diesel and 40-45 mpg from a Laguna petrol. I've also gotten over 160k miles out of a set of front brake pads.

07Lapierre

Bpmull wrote: »

I could be wrong but when the car is in gear and there is no acceleration then the turning wheels keep the engine turning revs going and uses no fuel as the momentum of the wheels. Keep the cylinders turning. When coasting the engine it idleing completely disconnected from the moving wheels and uses fuel. That's how I understood it but I could be 100 miles off never really looked into it.

Yes, what your saying is correct, except for the no fuel bit. The engine is burning fuel albeit a very, very small amount.

Bpmull

07Lapierre wrote: »

Yes, what your saying is correct, except for the no fuel bit. The engine is burning fuel albeit a very, very small amount.

You are probably right but my main point is it is using a lot lot less fuel this way than coasting.

07Lapierre

Bpmull wrote: »

You are probably right but my main point is it is using a lot lot less fuel this way than coasting.

Depends on how fast you are coasting

If you "coast" down a hill at 50kph while the engine is at idle speed, you'll save fuel, but if you put the car in gear and use the engine as a brake to travel down a hill at 50kph...this option would use more fuel as the engine would be running at much higher revs as it tries to slow the car down.

07Lapierre

07Lapierre wrote: »

Depends on how fast you are coasting

If you "coast" down a hill at 50kph while the engine is at idle speed, you'll save fuel, but if you put the car in gear and use the engine as a brake to travel down a hill at 50kph...this option would use more fuel as the engine would be running at much higher revs as it tries to slow the car down.

.... You're missing the point, the wheels are driving the engine.

Joe 90

magicbastarder wrote: »

i'm getting about 9 to 10c on petrol per kilometre at the moment, 1.4 octavia - a good deal of that is country roads, though.

one of the main factors in increasing fuel efficiency is anticipation - you see a lot of people burning petrol in accelerating up to a hard bend or red lights, rather than simply taking their foot off the accelerator and letting momentum do the work.

Yes, biggest fuel saver of the lot. Plan ahead, drive smoothly. Doesn't have to be slow, but smooth. Don't just look at what the car ahead is doing, look as far ahead as you can and plan accordingly.

Joe 90

BrianD3 wrote: »

Read the road, think ahead and anticipate in order to minimise use of brakes eg when approaching bends. Doing this is one reason why I get ~65 mpg from a Megane diesel and 40-45 mpg from a Laguna petrol. I've also gotten over 160k miles out of a set of front brake pads.

Pretty much what I said before I spotted this post.

magicbastarder

there's a belief that starting a warm engine uses the same amount of petrol as about 30s of idling would, the inference being that it's not worth killing the engine at lights if it's safe to do so.
it's actually far less than this, so generally speaking, if you're far enough back to give you time to restart the engine, you will save petrol by switching the engine off.

Bpmull

magicbastarder wrote: »

there's a belief that starting a warm engine uses the same amount of petrol as about 30s of idling would, the inference being that it's not worth killing the engine at lights if it's safe to do so.
it's actually far less than this, so generally speaking, if you're far enough back to give you time to restart the engine, you will save petrol by switching the engine off.

I suppose this is why many newer cars have stop start technology. Never gone on it my self but makes sense alright it uses very little petrol to start a warm engine

arleitiss

By the way just got a question,

If you are driving behind huge truck or a van, wouldn't that rapidly decrease your fuel consumption? I mean aerodynamics, the vehicle in front is cutting through the air , then airflow goes above them and over you? Would this not work that way?

areyawell

Going on a diet,exercise and losing weight will help any car gain extra MPG. There is a lighter weight in the vehicle. This was the main reason why I went on a diet to help save money on petrol.

johndaman66

arleitiss wrote: »

By the way just got a question,

If you are driving behind huge truck or a van, wouldn't that rapidly decrease your fuel consumption? I mean aerodynamics, the vehicle in front is cutting through the air , then airflow goes above them and over you? Would this not work that way?

You are correct in that such would decrease your fuel consumption. Formula One drivers often gain a few mph extra by entering the slipstream of the car in front. I don't think it would dramatically decrease it but stand to be corrected. I have read before that there is an optimum distance to sit behind the vehicle in front...too near and you won't get full benefit and too far away you won't either obviously....again not sure how much truth is in that one either.

At the end of the day remember the safety aspect though...only a fool breaks the 2 second rule and all that jazz. You may well end up iritating the driver in front too:)