Couple of questions

goonarmy

What are you expecting in terms of mpg? What are the publish extra urban mpg figures for your car? Id be expecting mid to late fifties in an ideal world off a small engined small car.

Brallaqueen

Hi Goonarmy - the official figures are 60-62.8 as per honest john. The 'real mpg' figures are a close match at 60.6 but i guess that includes more economical motorway driving etc.

http://www.honestjohn.co.uk/realmpg/seat/mii-2011/10


Iolanthe07 I hope it gets better soon too, currently just under 3000 miles on the clock so when can i expect the engine to bed in?


Joe Horner - thank you for expanding on AdrianC's comments, that's really useful. I am not the best at reading the road and thinking ahead.

Joe_Horner

Brallaqueen wrote: »

Joe Horner - thank you for expanding on AdrianC's comments, that's really useful. I am not the best at reading the road and thinking ahead.

You're welcome

One of the simplest (and most effective) thinigs you can do when you're in any sort of traffic is to try to get in the habit of watching cars as far ahead as you can see (obviously, don't ignore the ones nearer!)

If someone, say, 10 cars ahead of you put their brakelights on then just ease off the throttle a little and let the gap in front of you start to open up.
The chances are the cars between you will brake one after another, only reacting to the brake lights of the car immediately ahead. They're all wasting fuel.

As you see the brakes coming on closer and closer to you, lift off the throttle more to keep your gap open. you can also brake gently at this point for a second or two just so the guy behind will see your brakelights.

There's a very good chance that, by the time it would have been "your turn" to brake, the traffic will have started speeding up again and you can just go back on the throttle without ever touching your brake apart from to show your lights.

It also gives you a much smoother ride

thehappybutterfly

Joe_Horner wrote: »

Pretty much this.

Accelerating hard might use extra fuel (depending on the car to some extent), but nothing like as much as braking hard.

When you accelerate you're turning the chemical energy of the petrol into kinetic energy of the car. In a perfect world, it wouldn't matter at all whether you accelerated hard for a short time, or more gently for longer, because you're still adding the same amount of energy to the car. Things like mechanical efficiency and air resistance get in the way of that perfect world, but not by much.

A 1000 kg car travelling at 100kph (62mph) has a total kinetic energy equivalent to the energy you'd get by burning about a teaspoon of petrol allowing for typical efficiencies. So, in order to accelerate from stopped to 60mph, yoou'll burn about a teaspoonful of fuel.

When you brake, you're turning useful kinetic energy (from the car's speed) into useless heat energy at the brakes.

Imagine your car is doing 60mph as above and you let your foot off the throttle and coast to a stop. Your "teaspoon worth of fuel" that you burnt getting up to speed might let you continue rolling for another half a mile or so.

If, instead of coasting all the way (which is rarely practical), you plan ahead and brake gently, then that teaspoon might only take you 1/4 mile - about 400 metres..

On the other hand, if you do a full emergency stop then, using Highway Code figures, that teaspoon will only take you 55 metres.

The more you brake "late and hard", the closer you're getting to that emergency stop each time. Every time you do that you're throwing away distance that you've already "paid for" in fuel used when you accelerated. You then need to use even more in order to accelerate again.

So, think ahead, try to brake early and lightly, and watch your consumption improve!

At last, a proper explanation instead of just being told "don't brake sharply".

forgotmyname

I keep a quarter of a tank more during the winter. Too many hospital visits in the early hours to have to think where can i get some fuel from.

If your thinking of better MPG with little fuel in the car then dont bother. It will be neglible. Having to queue for fuel because you need it rather than filling up as you pass or because its empty will use more than you save.

I have sat in the lorry stuck in traffic for almost 6 hours during the winter. Watching the fuel gauge in the red section. But too cold not not have it running.

goonarmy

Google the top gear when clarkson drove from london to scotland on one tank for a simple explaination and some good tips.

Richard53

I agree with a lot of the above. Economical driving is all about preserving momentum. The less you use the brakes, the less fuel you waste in heat. Planning ahead and driving smoothly helps a lot here (but don't forget safety comes first - if you need to brake, do it! Nothing is more expensive than an accident).

To add a little to Joe Horner's post above, I have heard it said that on a clear road (e.g. a dual carriageway) it's better to accelerate briskly up to your cruising speed than to dawdle about taking ages to get there. Once you are at the speed you want, back off the gas as far as you can, and then look well ahead and adjust your speed by small movements of the pedal. Nothing wastes fuel more than howling away from a junction, only to slam on the brakes half a mile later for some traffic lights. Planned, smoother driving means longer life for your tyres and brakes, too.

If you are concerned about your fuel consumption, brim the tank when you next to a long trip, and check the consumption afterwards. I would guess you should be seeing about 60 mpg on a steady run of 50 miles or so. 40 mpg in stop/start traffic sounds about right for a small car.

Netwizard

Driving on the motorway is a good way to see how not to drive like a lot of people seem too.

A lot of people sit, like sheep, in lane 3, around 80-90mph. Slowing down, speeding up, slowing down, speeding up, like a concertina effect.

Meanwhile, I tend to cruise at around 70 in lane 1. Quite often passing slower traffic in lane 3 and getting to where I am going just as quick as the people bombing along in lane 3, who keep speeding up and slowing down!

Richard53

Netwizard wrote: »

Meanwhile, I tend to cruise at around 70 in lane 1.

In my last job, I did a lot of travelling between West Wales and West Sussex, and spent what seemed like half a lifetime on the M4. I found exactly this. If the motorway was congested, the quickest lane to be in (on average) was lane 1. As long as you anticipated well, and negotiated your way round the trucks in advance, more often than not you would be well ahead of the reps nose-to-tail in lane 3 after a few miles. It didn't work every time, but turned out to be a good general policy.

Also, I found it more relaxing for some reason. As it is technically 'undertaking' the vehicles in lanes 2 and 3, I'm sure it is contrary to the HC, if not actually illegal, but I was always prepared to argue my case if I were stopped, by saying that the vehicles were 'moving in queues' and my queue just happened to be moving faster than the others.

fivetide

jaydeeuk1 wrote: »

Petrol/diesel is over 100 million years old, not sure an extra month or two will make much difference.

No crude oil is.


Petrol/diesel are refined products.


You'll also find that if you store a vintage bike or car over winter you are advised to drain the fuel because otherwise modern unleaded petrol, with all those cleaner engine additives that you seem to think came from dinosaurs, because unleaded can start to solidify, turn into a jelly and gum up the fuel system, or it varnished the carbs and is a beggar to get off.