Fabia vrs mk2 fuel consumption

[lol-lol]

I did 11.1mpg at castle combe last weekend

Economical, use to get 5.9 mpg powering my 3.5 litre Rover up Longhope hill.

Edited 3 May, 2013 by lol

[BossFox]

Economical, use to get 5.9 mpg powering my 3.5 litre Rover up Longhope hill.

Sounds economical to me...

[lol-lol]

Sounds economical to me...

One vehicle I had only did 10 metres per gallon but then that was a 100,000 ton ship.

[Evil Miyagi]

35mpg is good for a car of this type, especially if you've only just got it and have been driving it quickly... IMO if you're driving it quickly and getting 35mpg you ain't trying hard enough

A bit more work and we'll have you the right side of 30 lol

In all seriousness though, it is what it is, a 180bhp turbo/supercharged petrol go kart.

I've had anything from 22 up to 51 on runs, round town I get about 28 - 32 (lots of stop starts).

Switch your Maxidot to the oil temp screen and drive it like you stole it!!

[Binzie]

Switch your Maxidot to the oil temp screen and drive it like you stole it!!

ha ha I learned that on day 3

[Richf]

Still have yet to better 38mpg and that's mfd figures I reckon I'm averaging 32-33mpg but I didn't buy a vrs to drive like a grannie

[Gerthmeister]

I do a trip of about 20 miles up the motorway an stick to 58mph on cruise but i do have fun when not on the motorway sometimes. And i do the school trip on my days off. But i averaged 41 over all. On a long trip up the motorway I'm averaging 51 mpg an 72 mpg if i can get the correct cruise mph set if I'm stuck up a lorries arse lol

[chappers777]

You've seen 72 average?! That's good and my cars off the road ATM but will try this when I get it back,

[Jabozuma]

I get anything from 21 mpg to 47 mpg. Recently on 50 mile M25 run with 50mph av speed cams and then hovering around NSL I got 43 mpg with two grown-ups and two 10yr olds no luggage.

It was mentioned here in a passing but I think it's worth reiterating.

-Overrun driving - when you coast in gear your injectors are closed and you are using no fuel. This is a very useful technique but sometimes it pays to coats in N as overrun would not get you where you want to be do to engine retardation and in the end you have to step on gas

- N Coasting - engine uses fuel ticking over in idle. Idle running uses special, very rich map and is very wasteful

-FULL throttle efficiency - sustained full throttle is the most fuel efficient as engine breaths to its max Volumetric Efficiency, AFR is also the closest to stochiometric proportions. However, this NEVER happens during normal road conditions and doesn't happen even happen on track. When we use full throttle we always accelerate. ECU adjusts fuelling according to a map called Acceleration Enrichment Map. If you ever followed a fast car and it was given a boot you could probably smell that strong smell of very rich, not completely burned mixture. When at full acceleration the mixture is substantially enriched and timing advanced to give you the best power. This is however very fuel consuming. There is also an argument whether you use more fuel accelerating hard('ish) for a very short time to get to your cruising speed or when you accelerate very gently over much longer time period. When at cruise speed and constant load mixture is being leaned out close to lambda 1 (diesels can run lambda 16!!!) or in case of Stratified Injection Motors it is much leaner, close to diesel lean levels with both chargers bypassed.

Hypermiling is a fine art where many things have to balanced out. I for example find that sometimes accelerating slightly down hill and coasting up hill gives me better mpg. Logic behind it is that gowing down hill it is much "cheaper" to get more speed which then can be scrubbed off while not on throttle up hill, which would otherwise consume much more fuel just to try and maintain your speed. This is not smooth driving but fuel saving.

Re being stuck in lorries derriers it should be very efficient keeping in mind shed like areo of vRS MK2 . I find it more mentally draining as you have to be on much higher alert for the lorry braking hard in front of you as the distance is next to non-existant

[Ootohere]

Basically the Twincharger can do pretty good MPG when at 2400 rpm and cruising in 7th gear.

(it also nicely picks up and goes from that revs and gear when asked to.)

If the Fuel being used ie 99 RON, or conditions allow that can be at around 70 mph.

A Re-map can sometimes mean you are able to cruise at 2400 rpm and the speed is well above 70 mph,

engines running well and the economy is still there..

Weight of Passangers, luggage, and weather conditions can adversely effect a Twincharger like no other car i have ever driven.

They can also obviously equally make all the positive improvements.

58 mph on a Motorway is not something i like to do other than where there are Speed Restrictions.

50 MPH Average Speed Camera runs, never give me as good Economy as in 60 MPH Average Speed camera Areas.

Thats where i get the Best MPG showing and actual happening over a longer distance.

george

eg 'Forced Economic driving' on empty roads!.

50mph-ish limit uphill on a Dual Carriageway is cr4p, downhill is quite good.

[Richf]

If the Fuel being used ie 99 ROn, or conditions allow that can be at around 70 mph.

A Re-map can sometimes mean you are able to cruise at 2400 rpm and the speed is well above 70 mph.

Go one then explain how a remap can effect the gearing of the car

[Ootohere]

The car is running better or as intended,

the Torque is being achieved and the performance means the car is sitting happily at 70 mph & 2400 rpm.

Well it can also when running better than Factory standard setting @ 2400rpm so is doing more than 70 mph,

using the same or less fuel than standard. EDITED.

Its not about effecting the gearing.

Actually in 7th is not the important bit, *There is not an 8th Gear to go to.* EDITED.

But in the Twincharger it happens to be where when all is running well,

and its at 2400 rpm, good Economy is available.,

It can be below 2400 rpm or below 70 mph if you like.

Usually thats not with 95 ron fuel in a Twincharger, and a re-map can help.

(no need to believe or even try if not interested)

Its just how it is, you are using little if not only half the available performance the car is running well.

No stress, little fuel use.

Not rocket science.

You might re-map for Performance, when not using the Performance (more Speed) that can equally be giving economy.

george

[Richf]

You already said that the car cruises well in 7th @ 2400rpm which is around 70mph*

Doesnt matter what modifications you do to the engine 70mph will still be at 2400rpm in 7th gear I'm sure you didnt mean to give the impression that it changes

Its possible that a car can be tuned or remapped to deliver better economy but that the savings on remapped cars are usually not because they are more economical at a set speed but that you require the throttle down for less time to get to and to maintain that speed also it must be considered that commonly the car is calculating the fuel usage based on the previous unmapped settings and hasnt been altered to calculate a more accurate figure on the current settings

*I'll take your word for that I dont cruise at 70mph

[Ootohere]

The 2400rpm is when the foot is on the throttle, or cruise control is on keeping up the speed,

as and when the speed is maintained, you can drop the revs and not lose speed, and if its easy to maintain or regain speed because thats easier to do and less throttle is required, that is fuel saving right there. EDITED.

Its an easy thing to prove or disprove, you run the standard ECU and you run the RE-mapped in the same conditions,

it makes a difference or not.

If it makes no difference then that will be that.

Coolant and Oil temp lower, engine running to optimum and economy can follow. 'Cooler', Engine is not stessed or less stressed,

Cooling fans not running in its self is good for the economy..

You can judge just between running on 99 ron or 102 ron at same ambient temperatures and see if their is a difference

in Performance or Economy at similar speeds and if the RPM is different.

[Jabozuma]

If ECU's are not able to automatically adjust to higher RON fuel and are not remapped it will make no difference whatsoever.

RON of fuel doesn't make any power it just burns slower. Those RON increasing additives added ar rafineries or available in shops simple slow down the combustion of the fuel air mixture. What it allows for is more timing advance and more power without the risk of detonation at the same AFR. So power is made without the need to increase fuelling.

I think what George meant was that at the same rpms you will be needing less loud pedal input with mapped engine or with higher RON fuel when engine can adjust itself.

Mind you, high RON will only help you at low loads, racing juice has high MON number, which is a measure of detonation resitance at high loads and temps.

[rcgliderpilot]

Something else to add to the mix...

Had my Fabia II vRS for 22 months now and still love it overall, but the fuel consumption has become an issue... Got the car at 3300 miles/6 mths, and for the first 20k after that it was relatively easy to get over 40mpg on a fast run with a mix of motorway/fast A/B-roads (see my review in the correct place on this forum...). Coming back from Switzerland to Calais at a sustained 75-80mph, I even got 45mpg indicated on the trip. A regular back-road trip of 35 miles gave a reproducible 38-39 on almost every run, while a standard UK motorway cruise at 75-ish gave 41-42. My daily 7-mile trip to the station would give 34mpg on the way, and 32 on the way back (uphill :-) ). This was on the original fit Dunlop SP Sport Maxxs.

However, 8k ago when the fronts were getting down to 2mm, I swapped all four tyres to Pirelli P-Zero Neros, which has turned out to be a mixed blessing. Subjectively, grip in the wet on the P-Zeroes is noticeably better than the Maxxs, and I've had almost no aquaplaning, but there are definitely some downsides...

Most noticeable is the fuel consumption, which has increased by at least 7% across all driving conditions. At first, I wondered whether I'd accidentally had the wrong size tyres fitted, but I've checked the milo/speedo against my wife's car and both are almost identical, so no problems there (subjectively, the car's performance seems unaffected too, which is what made me think it could be a changed tyre size to blame). It didn't occur to me that tyres could make such difference to mpg - I thought it would be 2-3% at worst... I even took the car into the dealer to have it checked, but they assured me all was well, and simply gave me a leaflet advising me that "different driving styles can affect your fuel consumption" - or something equally patronising, as if I had no clue about this sort of thing...

On a motorway journey, I now can't get more than 39mpg indicated, even going fairly carefully, so I can only conclude the tyres have made a big difference. Checking my [obsessive] fuel records, tank range has definitely reduced by 30-50 miles too, so consumption has obviously increased in reality. If anyone has any other input/suggestions, I'd be grateful. (Incidentally, the P-Zeroes have worn nearly twice as fast as the Maxxs too...)

Sorry if this looks as if it has turned into a 'tyre thread', but I thought it was relevant in the circumstances.

Cheers

Stephen

[Ootohere]

I like your post and your conclusions.

Tyres and tyre pressures make a big difference.

Why the new Markings & Stickers for those buying Replacement tyres really.

Wet performance, Economy & Noise.

http://www.ntda.co.u...reLabelling.pdf

http://www.blackcircles.com

george

[Jabozuma]

rcglidrpilot, it looks like P-Zeros have much higher rolling resitance than Dunlops Maxx you had before. This gives more grip but wears them off quickier as well. Nothing comes for free - you get better performance on one side the other side must suffer...

[rcgliderpilot]

Absolutely, Freedom! Just wasn't expecting 7%+ increase in fuel consumption - especially as performance doesn't seem to have suffered at all, let alone 7%'s worth... (and the grip is definitely significantly greater in all conditions, by the way, particularly round fast bends :-) )

[Jabozuma]

"Freedom"?

[Ootohere]

'Freedom' in green.

Means you have paid £12 to Briskoda.

Or Mel Gibson in 'Braveheart',. (William Wallace) I am in Scotland.

[Jabozuma]

Don't tell me he was alluding to the famous scene when they turned around and lifted their kilts?

[philhoward]

I noticed only a slight drop when moving to Winters; summers back on today (2 original Dunlops pronounced fit for a bit more life on the front, but Conti SportContact 5's on the rear) so will see if any difference on my next run to Germany on Monday. Will have to check before I get to the German border as my Autobahn driving speed can skew the results by a huge margin!

[Jabozuma]

I am sure you are aware that in Deustchland they require more thread depth than in UK .

I get bored quickly with top speed steady autobahn driving, especially night time. I prefer mixture, keeps you awake for longer. I must be getting older...

[rcgliderpilot]

Sorry Jabozuma... Accidentally called you "Freedom"... It's a long while since I've had time to post anything on this site, and I don't remember seeing 'Freedom' members before... Thanks for pointing out the error of my ways - I understand what's going on now.

And by the way, I'm still very surprised that tyres could make 7% or more difference to my fuel consumption...