Cheapest Petrol & Diesel Discussion Area

krishna

anewman wrote: »

Do the lights take half an hour to change or something?

No, but I read somewhere (may be it was here) that if you have to stop for more than 10 seconds, you use less fuel by turning off engine. Sometimes it is less than 10 seconds, but overall I'm better off that way. Lots of lights in London.

Lynsey

Just back from a few days in (rainy) Scotland and we filled up with our cheapest petrol for ages. £107.9 freely available in Glenrothes, both at the Morrisons' and Shell forecourts. I wonder if it will break the £1 barrier??

Lynsey

Rakesh.Chauhan_2

Use less weight - so try removing the spare wheel.

xtreem_2

You should never have to fill up at a motorway service station. Here is a free to use map http://www.thegreatmotorwaysecret.com/map1.htm
which shows all the superstores near to motorway junctions in England and Wales.

ChemicalJasper

krishna wrote: »

No, but I read somewhere (may be it was here) that if you have to stop for more than 10 seconds, you use less fuel by turning off engine. Sometimes it is less than 10 seconds, but overall I'm better off that way. Lots of lights in London.

I find this very hard to believe. As the previous commenter eludes to, starting the car takes a lot more fuel than tickover for 10 seconds.....and that is not to mention the added wear and tear on your starter motor and added load to your alternator to recharge your battery and the additional cycling of power to and from your battery and the added risk of the car not starting and the delay in pulling away leading to you accelerating harder than required from the lights. :eek:

Sorry but I do not believe that is good advice for the majority of people to follow!

AdrianHi

ChemicalJasper wrote: »

I find this very hard to believe. As the previous commenter eludes to, starting the car takes a lot more fuel than tickover for 10 seconds.....and that is not to mention the added wear and tear on your starter motor and added load to your alternator to recharge your battery and the additional cycling of power to and from your battery and the added risk of the car not starting and the delay in pulling away leading to you accelerating harder than required from the lights. :eek:

Sorry but I do not believe that is good advice for the majority of people to follow!

See the first item on this page under the STOP sign.
http://www.bmw.co.uk/bmwuk/efficient_dynamics/bc/homepage/0,,___,00.html?bcsource=nationaltop
Stopping the engine at the traffic lights turns out improve urban cycle MPG on the official EU tests to the extent it's worth designing into the way the car works.
I've driven a Mini with this start stop technology, it is pretty seamless and does not interrupt your drive at all.

ChemicalJasper

AdrianHi wrote: »

See the first item on this page under the STOP sign.
http://www.bmw.co.uk/bmwuk/efficient_dynamics/bc/homepage/0,,___,00.html?bcsource=nationaltop
Stopping the engine at the traffic lights turns out improve urban cycle MPG on the official EU tests to the extent it's worth designing into the way the car works.
I've driven a Mini with this start stop technology, it is pretty seamless and does not interrupt your drive at all.

OK granted for a car that is designed to do that.....

And perhaps for some small modern petrol engines, (the wear and tear comments stand!) .......:cool: but I am still sticking to my guns with older and especially oil burning lumps! - It takes about 3 gallon of diesel, 1.21 gigawatts of power and 30 minutes to start up my old 200 tdi!:rotfl:

AdrianHi

ChemicalJasper wrote: »

OK granted for a car that is designed to do that.....

And perhaps for some small modern petrol engines, (the wear and tear comments stand!) .......:cool: but I am still sticking to my guns with older and especially oil burning lumps! - It takes about 3 gallon of diesel, 1.21 gigawatts of power and 30 minutes to start up my old 200 tdi!:rotfl:

It's hard to know how long you have to be idling for before it's worth shutting the engine down and re-starting. I've heard quotes in the 20-30 seconds range before This BMW system works by shutting the engine down when you have the car in neutral with the clutch up for a couple of seconds. As soon as you press down the clutch the engine fires up quick enough to be ready to go after selecting a gear. There are other conditions when the engines re-starts or even does not shut down, such as aircon on full blast or other heavy electrical load. It's available on all cars with manual gearboxes including 4 and 6 cylinder diesels.
Mercedes are working on a similar system which will use the alternator as a motor to start the car rolling to make it even smoother.
The other thing is it lowers fuel consumption on the EU test which is rarely "real world". In the real world the efficient dynamics cars show a good saving on open road driving and not that much difference around town compared to their predecessors.

krishna

AdrianHi wrote: »

It's hard to know how long you have to be idling for before it's worth shutting the engine down and re-starting. I've heard quotes in the 20-30 seconds range before

I'm just letting people know the direct impact that simple changes to the way I drive have on my fuel consumption. I now automatically turn off the engine at lights, without waiting at all. If you wait, waste more fuel. I can't comment on the effect of this on wear and tear etc. on the care, but it has a clear benefit on my fuel consumption. Since I started turning off the engine straight away at lights, I now get 315 miles on 35 litres of diesel. i.e. around 100 miles more than I used to get, before changing my driving style and turning engine off at lights. Driving style improved my mileage by around 20 miles; turning off engine at lights (most of time, but dithering if I thought lights might change quickly) accounted for around 60 additional miles; turning engine off right away, on approaching lights as added to my savings by around 25 miles. These are based on actual tanks of diesel, not just made up figures. As for starting quickly when the lights change back to green, if I am first in line at the lights I turn the engine back on on an amber light and usually manage to be first off, so no delays there.

FRENCHIE44T

I am not suprised Tesco can give 5p/litre off, have you seen how much they charge? My local Asda (High Wycombe) is £108.9 and Tesco at Amersham is considerably more than that.