Amazing Fabia Greenline

[tonyfvrs]

I see three 'no no's' in this thread.

Tailgating lorries.

Running in neutral. Illegal.

Running tire pressures more than 10% out of spec. Illegal.

None of these to be recommended.

Boring old f..t.

I found this in the Highway Code

Control of the vehicle (117-126)

122

Coasting. This term describes a vehicle travelling in neutral or with the clutch pressed down. It can reduce driver control because

engine braking is eliminated

vehicle speed downhill will increase quickly

increased use of the footbrake can reduce its effectiveness

steering response will be affected, particularly on bends and corners

it may be more difficult to select the appropriate gear when needed

Regards

Tony

[Brin]

I found this in the Highway Code

Control of the vehicle (117-126)

122

Coasting. This term describes a vehicle travelling in neutral or with the clutch pressed down. It can reduce driver control because

engine braking is eliminated

vehicle speed downhill will increase quickly

increased use of the footbrake can reduce its effectiveness

steering response will be affected, particularly on bends and corners

it may be more difficult to select the appropriate gear when needed

Regards

Tony

Hmm, I thought it was, but maybe not illegal per say, but you are not in control of the vehicle. But trying to prove it in court if an accident occured would be next to imposible...

I got 82mpg in my old VRS, one of the most boring drives of my life! (round trip from liverpool to wolverhampton on the M6) god know what this must have been like.

[allytech]

Wow that really is good going, we see around the mid 80's in our bluemotion ususally ; )

[Guest]

I'm averaging mid to high 50's mpg !!! What am I doing wrong? Maybe it's because my average speed is 60mph over a regular 75 mile route mainly rolling with some steep hills 65% motorway/dual carriageway, 30% country road, 5% town ?

I can get 70mpg on a 3 mile route into town average 30mph, it's mainly downhill!

I think mpg comparisons are worthless without noting the average speed and distance travelled and type of terrain.

[seboni121]

I'm averaging mid to high 50's mpg !!! What am I doing wrong? Maybe it's because my average speed is 60mph over a regular 75 mile route mainly rolling with some steep hills 65% motorway/dual carriageway, 30% country road, 5% town ?

I can get 70mpg on a 3 mile route into town average

30mph, it's mainly downhill!

I think mpg comparisons are worthless without noting the average speed and distance travelled and type of terrain.

I can get 80mpg from my 1.4tdi 70bhp, so you will get better figure when you put more smiles on it

[Whitelighter]

I agree that's it's not recconended Tony

[MartynVRS]

I did once see 87mpg on my vRS trip following my brother home from my grandparents. It's about 15 miles either flat or downhill and doing no more than 50mph on a dual carriageway.

[Dempsek]

What a mpg figure, I wonder if he gives lessons?

The Fabia cuts fuel of to the engine if you run in gear with your foot of the accelerator allowing for all normal braking assistance.

If coasting in neutral could be proven and you were involved in an accident it is likely a magistrate would rule as driving without due care and attention. Why, while the high way codes does not say it is illegal, you are knowingly driving a car with less efficient breaks and driving without due care of other road users.

[seboni121]

I free wheel all the time, very steep hills here breaks are fine I've been on the planet now for 50yrs without any problems, yes you've got to make sure your in control but I've never felt out of control, the breakes will fade quicker and need replacing more often, but it's a sport get as much fuel as you can and how far you can free wheel safetly come on we've all done it lol, cant do it on the way home it's 1in 8 so it's thirsty on the way. Back!

[Junoman]

But freewheeling actually uses more fuel. As Dempsek said, modern cars cut all fuel to the engine on accelerator lift off i.e no fuel is burnt. When freewheeling you are still burning, albeit minimal, fuel because the engine is ticking over.

[apmaman]

Free wheeling in neutral is pointless, the engine then needs fuel to stop it from cutting out, if you keep the car in gear, the momentum of the wheels spinning will keep the engine from cutting out.

So if you get to a hill, whack it into 5th and let is roll down.

[seboni121]

Free wheeling in neutral is pointless, the engine then needs fuel to stop it from cutting out, if you keep the car in gear, the momentum of the wheels spinning will keep the engine from cutting out.

So if you get to a hill, whack it into 5th and let is roll down.

I understand this leaving it in 5 th on the hills but once on a more level ground, this will slow the car down won't it

As I can free wheel from home nearly 3 miles at a steady 50 mph

Edited 18 May, 2011 by seboni121

[Guest]

I can get 80mpg from my 1.4tdi 70bhp, so you will get better figure when you put more smiles on it

I've nearly done 8000 miles in it already!!

My point is that there needs to be a proper context when quoting mpg figures, otherwise they are meaningless. We all know how manufacturers achieve their figures because there is a standard that they must be measured against. however in real-world driving, there are many variables influencing the figures that different drivers quote.

I could get 1000mpg if I put my Furby on a rolling road where the rollers do all the work and just let the engine idle, or I could get 20mpg if I constanlty drove up a 30% incline with my foot to the floor on max revs in 1st gear.

So we really need more context to understand how figures are reached rather than just say my car does this or that mpg.

I don't believe that there is anything wrong with my vehicle, if I drove at an average speed of 40mph for my 75 mile journey, I'm sure I would get 70mpg, but I don't, so I won't, I doubt if I could do it as a large proportion is motorway meaning the non-motorway portions would need to be driven at 30mph or less just to get my average down, now that would be painful

[seboni121]

I've nearly done 8000 miles in it already!!

My point is that there needs to be a proper context when quoting mpg figures, otherwise they are meaningless. We all know how manufacturers achieve their figures because there is a standard that they must be measured against. however in real-world driving, there are many variables influencing the figures that different drivers quote.

I could get 1000mpg if I put my Furby on a rolling road where the rollers do all the work and just let the engine idle, or I could get 20mpg if I constanlty drove up a 30% incline with my foot to the floor on max revs in 1st gear.

So we really need more context to understand how figures are reached rather than just say my car does this or that mpg.

I don't believe that there is anything wrong with my vehicle, if I drove at an average speed of 40mph for my 75 mile

journey, I'm sure I would get 70mpg, but I don't, so I won't, I doubt if I could do it as a large proportion is motorway meaning the non-motorway portions would need to be driven at 30mph or less just to get my average down, now that would be painful

Yes I agree that why I take the other furby 1.6tdi down to bassingbourn I will be able to see how good it's going to be

[The PM]

I understand this leaving it in 5 th on the hills but once on a more level ground, this will slow the car down won't it

As I can free wheel from home nearly 3 miles at a steady 50 mph

If you can freewheel for that distance from 50 then its downhill, not level! As said if you leave it in gear it won't use any fuel, whereas if you coast in neutral (or with your clutch in) it will use fuel... Its a feature of many modern cars, and has been a feature of diesels for quite a while... If you are on a slight downhill stretch I'll lay odds that you can get similar mpg to coasting by very gentle throttle use...

If you don't believe it try sticking your computer on to mpg and then coasting, you will find it usually reads in the mid 100s, which you can also get with very gentle throttle on a slight downward slope, if you put it in gear and let it roll in gear and you get a line of dashes, showing no fuel is being used...

Of course, its easy to get carried away with this economy lark...

Edited 18 May, 2011 by The PM

[seboni121]

If you can freewheel for that distance from 50 then its downhill, not level! As said if you leave it in gear it won't use any fuel, whereas if you coast in neutral (or with your clutch in) it will use fuel... Its a feature of many modern cars, and has been a feature of diesels for quite a while... If you are on a slight downhill stretch I'll lay odds that you can get similar mpg to coasting by very gentle throttle use...

If you don't believe it try sticking your computer on to mpg and then coasting, you will find it usually reads in the mid 100s, which you can also get with very gentle throttle on a slight downward slope, if you put it in gear and let it roll in gear and you get a line of dashes, showing no fuel is being used...

Of course, its easy to get carried away with this economy lark...

Yes definate not as bad as I usd to be lol, I've not got the commuter methingy on the 1.4 tdi so it's guess work just stare at the digital display going down and down and down, but if I'm getting 80 mpg must be doing something right lol

[raisbeck]

if you put it in gear and let it roll in gear and you get a line of dashes, showing no fuel is being used...

Of course, its easy to get carried away with this economy lark...

Not quite true, but true enough for the point to be valid. The dashes appear if you are stationary ticking over as it cant calculate mpg if your not moving. It also shows dashes if your mpg exceeds 200mpg. You can check this if you go on a reasonable downhill section, the display shows --- but take your foot off the power and the car does slow.

More realistic mpg figures could be gained by using trip 2 values. If you dont reset it then you can see your cars average for its entire life up the the point it was last reset. Havent reset mine for 10000 miles and it shows 72mpg. In reality this is about 68mpg. The peaks are summer with 76 mpg possible with careful driving and as low as 60 in really cold weather.

I used to try all sorts to get excellent economy. It gets boring very quickly so now I just drive normally. On the speed limits...ish most of the time. This puts me usually about 5 mpg under the official combined figure for this car......seems about right.

[Alan C]

Hopefully everyone coasting is leaving the engine running - you need to provide the servo assist for the brakes!

So question is whether you need more energy to push the engine round at 1500rpm say, coasting at 50 in 5th, or going round at 1000rpm on idle - I'd say the idle speed probably uses less energy. The energy to turn the engine has to come from somewhere. Of course this is only an issue if the slope is gentle enough for you to be losing speed with your foot off the accelerator - if you are going downhill fast enough in gear then you'd need the brakes if you were in neutral, so that would be a waste of fuel.

Having said that I tend to stay in gear, I find the engine braking is minimal at low revs and don't worry about it. But in light of this I don't think being in neutral his has much bearing on braking ability, or safety - in fact some (polo!) TDI drivers report a sudden surge coasting to a junction, presumably when they don't notice they've dropped below idle speed, and frankly would have been safer in neutral.

[mrgf]

I see three 'no no's' in this thread.

Tailgating lorries.

Running in neutral. Illegal.

Running tire pressures more than 10% out of spec. Illegal.

None of these to be recommended.

Boring old f..t.

Not sure about running in neutral actually being illegal... Tailgating would be far worse in real terms and perhaps illegal anyway as driving with undue care or dangerous driving offence may be being commited.

But, remember, this was in a different country, not here. Many regulations here may bear no relevance there!

[mrgf]

Modern cars DO NOT cut the fuel off when not accelerating... This is the equivilent of stalling and braking forces will be greatly reduced, along with power stearing!

What SOME cars do is cut the fuel when the car is stationary, with the brakes applied and the clutch down. it wil then re-start if you touch the gas pedal. There are probably differing methods but it will always be a stationary vehicle. It would simly not be safe to switch off the power whilst moving!

Fuel, however minimal, will always be being used whilst running the engine and stop-start systems may actually use MORE if all you are doing is stop-start traffic as it uses MORE whilst just getting started again. (Not as much as a cold engine but more than just ticking over). However, turning off when stuck in proper jams IS worth the difference. Stop-start will also add a big drain to the battery... In another decade, you will see lots of these cars needing new batteries as they have killed thier standard ones.

Edited 19 May, 2011 by mrgf

[danny_f]

Modern cars DO NOT cut the fuel off when not accelerating... This is the equivilent of stalling and braking forces will be greatly reduced, along with power stearing!

What SOME cars do is cut the fuel when the car is stationary, with the brakes applied and the clutch down. it wil then re-start if you touch the gas pedal. There are probably differing methods but it will always be a stationary vehicle. It would simly not be safe to switch off the power whilst moving!

Fuel, however minimal, will always be being used whilst running the engine and stop-start systems may actually use MORE if all you are doing is stop-start traffic as it uses MORE whilst just getting started again. (Not as much as a cold engine but more than just ticking over). However, turning off when stuck in proper jams IS worth the difference. Stop-start will also add a big drain to the battery... In another decade, you will see lots of these cars needing new batteries as they have killed thier standard ones.

Sorry mrgf, I have to disagree with you there, if you are travelling down hill, in gear without acceleration, the engine 'motors' round, its rotated from the wheels, through the gearbox and this keeps the crank turning pulling air through the engine creating a vacuum for the servo assisted brakes and driving the ancillary belt, turning the alternator and generating electricity. Because the engine is being motored by the kinetic energy of the vehicle, the ecu say's to itself 'i dont need anymore fuel to turn the engine' and cuts the injectors, unless the driver demands more power by pressing the accelerator pedal. Power steering is electric so will still work fine.

Stop-Start systems may cause battery life to reduce but a figure I've heard thrown around before is that if you're stationary for longer than 7 seconds its better to have switched off your engine. I think this figure has been reduced somewhat because of the improved reversible alternators (instead of separate starter motors) fitted to stop start vehicles that start the engine much quicker than traditional starter.

[danny_f]

...anyway, incredible feat an interesting article and I can only aspire to one day get anywhere close to averaging 127.8mpg in my greenline over a 2000km journey (If Skoda ever get around to making it!)

Edited 19 May, 2011 by danny_f

[Dempsek]

Here is the answer to if a car cuts fuel to an engine or not when the accelerator is lifted and more.

The answer from the AA, http://www.theaa.com/motoring_advice/fuels-and-environment/drive-smart.html

[Guest]

So after running at 55mpg for months now at normal speeds, I decided to try an economy run on my 75 mile commute, so at 60mph for 65% of the journey on motorway and dual carriageway and an overall average speed of 50mph (10mph less than normal), the maxidot was reading 73.7mpg, so nothing wrong with my greenline2. I was only 10 mins slower than when running at 80mph on the motorways, for nearly a 20mpg gain, that's pretty good, and it's quite relaxing traveling at 60mph on the motorways.

Edited 20 May, 2011 by Guest

[Ad Lav]

Interseting to know

Me and the misses are off to the Lizard in Cornwall from Tunbridge Wells in Kent this summer, we'll see what the vRS can do on long journeys at varied speeds as I would like to get there on one tank lol

Will have to put my eco shoes on and drive slow and leave early lol