Great "Cutting the Cost of Driving" Hunt: Liftshares, carclubs and more.

waynedance

i am not sure on this coasting, i prefer to coast as you can roll much further but if left in gear the car slows much quicker so you need to put your foot down more.

I have tried both and watched the fuel computer and believe costing is better for me.

I do use cruise control allot which helps as the car uses what is needs.

Charis

matt_outandabout wrote: »

No journeys by car = huge savings!

The average care journey in the UK is under 3 miles

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No journeys by car, if you don't live in a city = higher public transport costs, taxi fares if your journey is after 11pm or before 7.30 am, or on a Sunday or a Bank Holiday. Hourly buses at best, often with an hour or more wait between connections if needing more than one bus, and walking on 60mph roads without footpaths if you live out of town.

The average car journey in rural areas is at least 10 miles. I wonder where the 'average journey' statistics are compiled, since no one has ever asked me how long my average journey is.

Re. the tip to not carry a full tank of fuel due to the weight, don't wait till you get to the bottom of the tank to fill up either, especially if you have an older car, as it is expensive to have the car repaired if the fuel system gets clogged with sludge.

Gorf123

Coasting while in neutral only helps with older engines. Newer ones with fuel injection use no fuel when coasting in gear.

You can reduce other peoples' fuel bill by paying attention when stopped at the lights and moving off as soon as they change. It's very annoying when the dipstick at the head of the queue takes so long to work out what's happening that I have to stop anyway.

almillar

Re: Coasting. It depends whether you WANT to slow down or not. If you've ages to travel, coast, this uses idling fuel and keeps you moving a long way. Slowing down in gear slows you down faster (and even faster in a lower gear) and usually uses no fuel. But there's no point in doing that, then having to accelerate again, then you should have coasted.
Also, the point about not being in control whilst coasting. On a very steep hill (where you should stay in gear to hold the car back and not stress the brakes) or whilst cornering this is absolutely true. But in 10-30mph traffic, in good weather conditions, I don't see anything wrong with it. If you're actually concentrating on your driving enough to be thinking about coasting/slowing down in gear/reading the MPG on your car, I'd suggest that you're concentrating much harder on your driving than most people on the road, and are probably the safest driver in the queue!
HTH

Growmac

ROCKIEDOG wrote: »

My tips, get into top gear asap. I drive around towns at 30mph in 5th gear at about 900rpm. Engine has no trouble with this.
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I'd strongly argue against this. First I'm not sure that it's the most fuel efficient way of driving. Most engines are most fuel efficient at the point of peak torque. While for a diesel this might well be around 1700 rpm, 900 is not going to be good.

Secondly, the main bearings on a car engine are hydrodynamic. This means that there are no metal balls holding the crank away from the block - the crank rides on a cushion of pressurised oil; there's no contact at all. Very low rpm means that the oil pressure will be very low - you're risking the long term health of the engine as there will be far more chance of unwanted contact.

Just my opinion...

wiggers

ROCKIEDOG wrote: »

I drive around towns at 30mph in 5th gear at about 900rpm. Engine has no trouble with this.

This is not good general advice. It may be ok for your car, which I suspect is fairly powerful, but for an average car under 2 litres this is likely to cause damage. Generally, for a 5 speed gearbox arrangement, 5th should not be used below about 40mph, preferably 45. At 30mph you should be using 3rd or 4th depending on your gear ratios and engine size. If the engine sounds lumpy it means it is not happy and you should use a lower gear. For the technically minded, the engine needs to be developing enough torque for the speed and conditions. You need to know what the torque curve against RPM looks like.

The two main things that use fuel when driving are acceleration (increasing momentum) and wind resistance. To use the least amount of fuel you need to use the engine at its most efficient range while accelerating. This means using around 75% throttle and changing up when you are past maximum torque, usually around 3000rpm for petrol, lower for diesels. Also, only accelerate to a speed that will keep you going for as long as practical. No point accelerating to 30 when you can see a queue ahead and you'll have to brake again. As others have pointed out, all the junk in your car also has to be accelerated to the same speed. Every kilo of junk adds to the amount of fuel burned each time you accelerate. (This is why using the Cruise Control is a Good Thing, it is keeping the car's momentum constant.)

The second primary use of fuel is overcoming wind resistance. This is in proportion to the cube of your speed, so at 80 you are using nearly 50% more fuel to overcome wind resistance than at 70mph. Although with other resistance factors, such as tyres (check those pressures!), the total consumption doesn't go up quite so much, but it is worth bearing in mind. Again the torque characteristics of the engine are important. So keep the outside of the car 'clean' - remove roof-racks and top boxes as soon as they're no longer needed. BTW, I'm not convinced by the open/closed window argument. Most of the drag occurs at the rear of the car, so the cross sectional area is the major factor, which is why large 4x4s have appalling fuel consumption at speed compared with a saloon.

wolfehouse

i was amazed to see that the city of edinburgh has started a car club
http://www.edinburgh.gov.uk/internet/A-Z/AZ_city_car_club

i thinks it's a brilliant idea and they have said if you have parking available they might site a car near to you (so more convenient iyswim)
i wouldn't be able to use it as i need an automatic, though.

steve6375

I own a 2.2 Vectra. I used to get a measly 24mpg doing a 10 mile journey to work and a 10 mile journey from work in my normal non-aggressive driving style. I now use a combination of techniques and get 30mpg!
Techniques I use are:
1. Predicting road ahead - take foot off accelerator well in advance of a junction or slower traffic. Avoid braking and don't accelerate if you can see that you will need to slow down in a short while.
2. Take your foot completely off the accelerator as soon as you can - don't brake before a corner, take your foot off well before instead.
3. Coast - I have an auto and I can coast for 1/2 mile downhill in neutral in places - all at 180 mpg according to the on-board computer. e.g. 1/2 mile uphill at 15mpg followed by 1/2 mile downhill at 180 mpg = 27mpg avg. compared to about 20mpg if I did not coast.
4. Get up to top gear using mild acceleration quickly, then only accelerate mildly when in top gear.
5. Keep top speed as low as poss - 65mph saves a lot more fuel than 75mph!

Strangely, having a fully loaded car does not make that much difference to me if I coast a lot (on hilly terrain). On some journeys (hilly) I get a better mpg! I think this is because it uses only a few mpg more going uphill with a fully loaded car but I can coast for a lot longer downhill due to increased inertia/momentum.

Coasting is only really practical at speeds below 50mph or so - above this the air resistance slows you down very quickly so you cannot coast very far. Not suitable for motorways.

Note that the difference between 1/8th throttle and taking your foot right off is enormous - so take your foot off completely whenever you can rather than just lifting your foot slightly to slow down.

Of course, only coast when it is safe to do so!

HTH
Steve

jeferey

I've started using some of the techniques listed above and made use of some others listed on http://www.hypermilers.co.uk - interesting!
I've found defensive driving, coasting in neutral and in gear and just going slower works best.

Welshlassie

Slip streaming behind large vehicles like lorries can also reduce the power needed by the engine. Obviously not getting to close that you are tail gating, but going up hills or just before overtaking can reduce your consumption by a small amount and it all helps.

Before starting to drive economically I would average 54mpg on teh motorway, since starting I now regualrly achieve 65mpg on my 36 mile commute to and from work and last week got up as far as 69.5 mpg, was convinenced I was going to reach 70mpg until I hit traffic 3 miles from home.