I don't want to start another what consumption do you have thread but averaging just 42mpg with my 2.0 pd tdi, I'm getting rather paranoid seeing figures quoted by others of 50-60!, some even with vrs engines.

Mine is an accurate 42 with a decent chunk of my mileage at a steady 70 on a motorway and dual carriageway. Now I know some of the other figures I see are maxidot overestimates and driving style has an influence, but surely this doesn't account for as much as 20%-30% in worse performance?

I can rule out binding brakes, and all my filters are new. So is there any other thing else I can investigate? I have no vcds errors showing and have 100k on the clock. Also perhaps strangely things haven't improved much in the better weather.

Thanks

Adam

Try a steady 60 on the motorway, I have just done that and found an increase of 12-15%, nice to see anther welsh boy on here. Bob

Does seem rather low- I'm wondering are your tyre pressures correct and do you have the aircon on all the time/ drive with the windows open. Are you normally fully loaded? Also don't take this personally but what's your driving style like as this will have a significant impact on your mpg- As an example I can normally easily get around 5mpg more than SWMBO in her car simply because of the difference in the way we drive. I'll not tell you what my vRS is doing :-)

Bob, there's a few of us, nearly as many as Lions Players.... if I go at 60 I can push it nearer 47 on average. And littleade, I do run aircon but have turned it off with little gain. And I don't drive loaded, or with low pressures, and i'm quite a conservative driver - I think!!! Thanks for the replies.

Adam

I only get about 50 mpg average over a tank of fuel in my fabia greenline 2 if that makes you feel any better & to be honest its probably because i rag it everywhere & my journeys are short, i do 15 miles to work & back & the rest is town driving.

Like you i was a bit worried about it,or more to the point annoyed but now i just accept it, i've tried everything in the book & its made no worthwhile difference so now i just drive how i drive,the issue ive got is that more powerful cars i used to own that werent supposed to be economical didnt come too far from this figure whilst driving the same way.

On my most boring "stuck behind a tractor or truck" journeys i can squeeze out about 65mpg but if the roads are clear then i've no intention to stay at such low speeds.

Fair point. I was more worried in the past but lived with it too, but lately I've seen some high numbers and it has me thinking again...

Sorry none of my suggestions helped. One other thought are you using supermarket diesel? I don't use anything other than shell or esso myself and put millers in too but have seen posts elsewhere when guys are getting less mpg using supermarket diesel when compared to shell/esso etc. All the best. Ade

No thanks, am happy to hear suggestions. I rarely use supermarket fuel but when I do it doesn't make much difference.

I am actually beginning to wonder if there is something more mechanical that I should look at.

Adam

Oh well, at least it looks like you've ruled out the obvious possibilities, final thoughts are how long have you had the car and has the mpg been constant. One last thought is does it need a decoke. That's it...I'm out of ideas now!

Hi Adam,

Isn't 47 MPG close to the official figure for your car? I think it's 51 for the manual gearbox according to quick check on Parkers.

Also the vrs's you are comparing to may be CR rather than our* less efficient PD engines.

*I'm awaiting private number plate transfer before i get mine, so please forgive my noobiness!

Bob

Thanks both for the replies.

Littleade: what is a decoke?

SurreyOcy: while I can get 47 driving at 60 it goes down once I mix it with a bit of urban mileage to my average of 42, i.e. mixed which I think should be compared to the figure you refer to?

Thanks both for the replies.

Littleade: what is a decoke?

SurreyOcy: while I can get 47 driving at 60 it goes down once I mix it with a bit of urban mileage to my average of 42, i.e. combined which I think should be compared to the figure you refer to? I know the official figures are optimistic but I feel I should be closer. And looking at short urban mileage runs is where I think I lose most, I rarely get much over 30 on those! As to the engine type, I start thinking about this when I see figures quoted by those driving the 2.0 140pd or 170pd. As to the figures for the 1.9pd or cr engines, its only jealousy I feel and I don't make comparison!!

What's this issue about supermarket fuel?

I don't use it simply for it's not available here (virtually all pumps are branded, even those in supermkts) but as far as I know (and I was told by a former client, being it a major fuel brand), pumps are delivered with the closest available fuel (i.e. from the closest refinery or deposit) because of the huge incidence of transportation cost over the fuel total cost.

The very same fuel brands do this (they deliver with their branded tankers but buying it from the closest deposit, even a competitor's or an independent one), not counting the pump owners who should be obliged by contract to buy from the "parent" brand but "sometimes" buy from cheaper providers.

In fact, a recent test made by car magazine Quattroruote over fuel coming from all different brands AND from "independent" pumps found virtually irrelevant differences in all parametres (i.e. sulfur content, etc.)

Edited 12 June, 201312 yr by duro

I only get good MPG on an out of town run.

In the last 2 weeks I've done round trips from Middlesbrough-Scarborough and then Middlesbrough-York,

each one giving an average of 56-57MPG according to the trip computer. Even with the inaccuracies this is still

decent.

I know it doesn't help you though!

Ah, the decoke..... Over the life of an engine you get carbon deposits building up on tbe internal surfaces of the cylinder head, valves, pistons and the turbo. This disrupts the fuel mix flow so the engine becomes less efficient and emmissions increase. There's a system called terraclean that removes these deposits, though I don'tknow how 'good'it is. The old 2 stroke bike engines used to coke up and I used to take the head off, polish the carbon off and scrape it off the exhaust baffles. This was the physical route which wouldn't be worth doing on a car engine just for the sake of it. I've seen elsewhere that the turbo can become clogged and some use mr mussles oven cleaner and theres a how to guide on the forum somewhere-though I don't know if it would do anything to improve mpg. As far as supermarket fuels are concerned, yes they come from the same refineries, but each brand has it's own set of addatives. A am example I saw a test on 5th gear on petrol and asdas unleaded produced less power on a rolling road during a controlled test than esso and shell even though tbry had the same RON. I belive it's no different with diesel with the branded ones having better/more detergents etc to keeo the engine running cleanet which in turn helps with mpg. I usr millars which improves the cetane number too in my CR and this I find improves mpg by a couple of miles and my engine seems to run smoother, so all diesel fuel isn't the same, hence my question as that might be one of the reasons for lower mpg. I'm not suggesting it IS the cause just MIGHT be something to consider/rule out/as a factor. HTH

A lot of diesel owners on here feel the 'need' to justify the mpg claims of the Diesel engine. In reality they get nowhere near the 60mpg daily figure but they won't tell you that. I drive a LOT of different cars for work and all of them are diesel, I am required to note the mileage for each journey taken and have full computerised print outs of the fuel each car uses from our own fuel pumps. This is a constant running total over the whole year and accurately gives the consumption of each vehicle wether its a car/van/HGV etc.

Our cars also have data logging with a red/amber/green light system on the dashboard which alerts fleet manager to harsh driving etc so you cannot rag the life out of the vehicles or if you do expect to get your access to fleet vehicles withdrawn.

The whole point of above is that most of our diesel cars are in the 35-42 mpg range over the whole year doing pretty big mileages not the 60+ often mentioned on here. If people are getting those sort of mpg's daily then they must be sitting slipstreaming lorries at 56mph 24/7. As an example I have just last week had a Kia Ceed 1.6 Crdi ecodynamcs with stop/start to use for a few journey's when I got back and checked the fleet system it had averaged 51mpg in total for a week and that is our best car out of the Ford/VAG/GM fleet !

People over egg it on here fella so your car is operating well according to our fleet !

I have always been keen on consumption figures, and the economy was one of the reasons I chose my particular car. I find that consumption figures, as has already been stated, can vary between road conditions, the was in which the vehicle is driven, the weather etc. etc.

I tend to take the computer figures as displayed as a rough guide only, and I find that the only way I can get a reasonably accurate reading is to log every drop of diesel and make my calculations over a period of time, say monthly. I suppose I folk think I'm a bit of an anorak by doing my consumption figures this way, but so be it, it is something I have done all my driving career, and I'll continue to do so till I stop driving.

I purchased the car new in May 2012, and using my system, the first 12 months saw me cover 12,441 miles, using 208 gallons of diesel, giving me an average of 59.81mpg, a figure I am more than pleased with. A recent holiday in Scotland and the North-east saw a rough average of just over 72mpg over an 8 day period, and last year, a 15 day tour of the Outer Hebrides and Highlands saw my average exceed 70mpg. (That's including motorway and dual carriageway driving at between 60 and 70.) A 14 mile round trip to work, including a 1 mile steepish incline, according to the computer gives 58mpg.

As you can see, I am more than happy with my consumption figures, they are obtained with mostly Shell diesel, with a tankful of the V power fuel every 6 months, just to help keep the system clean, and I always put the metric equivalent of gallons when filling up.

I like to consider I am a reasonably careful driver, I drive defensively, to the Advanced Police system (being a retired traffic cop!) and I can honestly say that the Octavia is one of the best cars I have had the pleasure to own.

I don't "feel the 'need' to justify the mpg claims of the Diesel engine" as I have to report to nobody.

I live in the province of Milano. Going around my "countryside" (which is pretty trafficked too) I regularly achieve 55MPG on my Octavia 1.6TDI (on my wife's petrol Yaris 1.0 I get 60MPG.)

Today I've been to other other side of the city (3 up), so driving almost all of the trip in heavy traffic. Back to home I checked: 45MPG.

Please note that I – as most Italian drivers – virtually never care of speed limits (unless a speed camera is likely to be out there).

With my Suzuki V-Strom 650 I achieve (on mixed ways) 62-70MPG.

Maybe the "secret" is I use high gears a lot – unless the very moment of overtaking et similia –. My wife, who "pulls" gears more than me (without being a bad driver either) achieves about 10MPG less on same road/car.

Staying below 45MPG with a modern diesel car means driving ALWAYS in heavy traffic or driving ALWAYS fast or driving, well, quite badly (eco-wise).

I dunno about you guys, but this is mine, fuel consumption-wise.

http://www.fuelly.com/driver/mysticality/octavia

Thats combined highway, town (country towns) and city (Sydney CBD, lots of traffic and lots of boost)

Thanks for the replies all, each is very helpful.

Bullit, the useful long term averages of a larger sample you mention are perhaps a better benchmark for my car and indeed my own figure is a long term average, based on tank fills etc and mileage rather than the trip computer. I do believe though that VAG diesels are generally more frugal than others so perhaps its fair to assume my engine is below average but within expected range.

Littleade, thanks for taking the time to explain the decoke, I might try some additive, or an occasional tank of the better stuff out of interest to see the effect or if it pays for itself or better.

Thanks again all

Adam

A recent holiday in Scotland and the North-east saw a rough average of just over 72mpg over an 8 day period, and last year, a 15 day tour of the Outer Hebrides and Highlands saw my average exceed 70mpg.

I'm sorry but I simply don't believe that, even if you say you keep track, maybe being an ex policeman like some statements your figures have been written in 'pencil'

If you say it's true then you simply have the best performing lightest Octavia estate in Europe with the best VAG group 1.6 Diesel engine.

I dunno about you guys, but this is mine, fuel consumption-wise.

http://www.fuelly.co...icality/octavia

Thats combined highway, town (country towns) and city (Sydney CBD, lots of traffic and lots of boost)

you're driving the wrong way up so your fuel figures don't count LOL :rofl:

Adam,

Yeah that Terraclean was on wheeler dealers- they used it on a big petrol car that was struggling with the emmisions - a Jag IIRC and it certainly cleaned it up though I'd be a bit cautious about the mr muscles route if your carr is otherwise ok- ain't broke don't fix it type of thing....

Any hoooo,

I've just logged on via laptop rather than my daft phone so didn't see what your driving until now.... SWMBO gets low 40's on the trip computer out of her 1.9PD 105 Seat Altea (though machanically sympathetic she ain't! and as above I can get more than she can, but then I get more from my CR 170 and other threads I've seen tend to suggest the 140 isn't as good on diesel as the 170) so an accurate 42 out of a PD140 isn't that bad I guess as it is older technology and less fuel efficient than the modern CRs ( head down waiting for flack....). If you've got lots of hills where you live that'll mess your consumption up too. If you look at other threads for the so called economic cars there's some interesting stories about with people driving 1.2 petrols and getting less than my vRS- now that would make me wince but they seem quite happy. Have a play but I wouldn't be overly concerned mate

<p>I only get 38 at best 43 from my CR170

I'm sorry but I simply don't believe that, even if you say you keep track, maybe being an ex policeman like some statements your figures have been written in 'pencil'

If you say it's true then you simply have the best performing lightest Octavia estate in Europe with the best VAG group 1.6 Diesel engine.

t

Thanks. I'm not messing with the turbo, have no fear!! Having done 100k and the fact its working fine at present means I'm not going to tempt fate (although by saying this I probably just did!!!!)