Disappointing mpg - is it me?

[Mehitabel]

Hello there

Thought I'd try and draw on the considerable collective knowledge and experience here. Am REALLY disappointed with the Roomster mpg (is a bog-standard 1.4tdi, 2007 model, one previous owner, 41K when I bought it, have done about 9K miles myself). Have ONCE managed to get over 50mpg (about 52) on a tank which was exclusively long-haul. I mostly potter around country lanes in it but it sees dual carriageways for avg 1/2 -1/3 of every tank. The last tank was a paltry 38mpg.

My friend who seems to know about such things keeps saying it's the way I drive, but my last Skoda ('02 Fabia 1.9SDI) pretty much routinely got 55mpg, regardless of the type of journey, and my driving hasn't changed between cars!

I realise that the engine is totally different (3-cylinder, turbo) and there's more drag, but I can't believe it accounts for the huge variation in consumption.

It was a choice between this and a Roomster2 1.9, 2006 with 61K miles for same price. I'm wondering if I did the wrong thing, cos I feel like I'm getting 1.9mpg with 1.4 peformance, so I might as well have had the 1.9!

I miss my Fabia so much. Would still be driving it if a prat in a 4x4 hadn't driven into me (going too fast in the lanes on an icy afternoon), but the redoubtable Fabia protected me (even though this thing landed ON TOP of us!), my unborn baby, my husband and dog. RIP lovely car.

Am I just unlucky? Is there something I'm doing wrong or could fix/change?

Any advice appreciated.

[hertsnminds]

Not sure what the quoted MPG of the diesel is but 38 sounds low. My 1.2 petrol is giving around 40MPG on a regular basis with mixed motoring and on a long run can easily get over 500 miles from a tank. One thing that seems to alter the figures is ambient temperature, with the numbers dropping to about 36MPG during the Winter.

[keystonedriving]

I also have a 1.4TDi Roomster, having graduated from a Fabia 1.9SDi, followed by a Polo SDi.

The Fabia returned about 53.5 mpg over 135k, the Polo 54.3 mpg over 173k. That included a lot of low gear work with learners, so I reckon it was pretty good. I really miss that lovely low rev torque, smooth power delivery from about 600 revs (learners don't always get the right gear, but the SDi could get them out of trouble). The TDi has more power but less torque so you have to rev it harder, therein lies the problem.

With the Roomster I am getting about 51.5 mpg over 30k so far, but I have had to adapt my driving style to acheive this. I have found that by driving with a light touch it can be very economical around town but is less so on a run, unless you keep to about 60/62 mph. According to the computer, on last Sunday night I got from Woodford Green to the M3 start (around the North Circular Road) at 69 mpg! The computer on mine is about 5-7% optimistic, I think. The overall journey was completed at an indicated 60 mpg, with the cruise control set to about 62 mph.

A journey I often make, from Redruth to home (near Launceston) takes about an hour. The difference between cruising at 70 and cruising at 60 is about two and a half minutes (in reality) but the difference in fuel consumption is about 8 mpg. I'm not sure why the Roomster is quite so heavy on fuel, it's only a couple of inches taller than the Fabia so the frontal area isn't hugely different. It may be a little heavier, but again not by a great deal.

Perhaps we need to visit the Fabia section to see what differences they have found between the two engines.

The other point which comes to mind is that as we are in Cornwall we are always going up or down hills, which probably won't help either. We probably wouldn't be having these problems if we were in East Anglia!

Rob.

[Mehitabel]

Thanks for your replies.

Rob, I have found the same on a run, ie really marked difference between 60 and 70. Will be interesting to see what the Fabias do, good idea. Totally agree with your remarks about the Fabia 1.9SDi. I mourn mine every time I see one out and about! I have been trying REALLY hard to drive with a light touch (if that's not a contradiction), and I think I'm getting better - slight improvement in consumption. It's a challenge...

[dieselglider]

These are my figures for the past couple of years-ish. The figures relate to (computer mpg) = (true mpg).

'08 Roomster 1.4tdi 80bhp

22/07/10 to 23/07/11 - true 53.0mpg average/year

26/06/11, 61.1 = 57.1mpg.Maxol

17/09/11, 59.1 = 54.3mpg.BP

04/10/11, 62.8 = 56.4mpg.Maxol

12/11/11, 57.4 = 53.2mpg.Sainsburys

07/01/12, 55.1 = 51.2mpg.BP

15/02/12, 55.9 = 52.3mpg.Maxol

18/03/12, 57.1 = 52.5mpg.Maxol

14/04/12, 58.5 = 53.8mpg.BP

I've been impressed with the driveability, plenty of torque, except for the first few minutes after a cold start. Generally get about 500 miles to a tank. No real heavy traffic where I live, and journeys are mixture of short and medium.

Usual checks would be Air Filter, Brakes binding, Air Flow Meter fading?

[pinkpanther]

The newer ones are no better - mid 40's mpg from my 2012 1.6 CR Tdi.

[grafitti]

I have gotten very good performance from my 1.9 TDi. my average is between 55-60mpg. There are not many hills to go up, though, and over half the travel is motorway, so that may be one reason for the good figures. Aside from the first 5 minutes after a cold start, where the consumption is closer to 20mpg, it quickly shoots up after the engine warms up. Absolute worst I've gotten is 38mpg - cold starts, harsh driving, stop and go traffic. I do not find much of a difference between 60 and 70 mph. Minor change of maybe 3mpg more. Going up to 80 mph does use more, and I do have to fight myself from drifting over 70.. as every car has a natural cruising speed which you settle into if not paying attention, i find the roomster to do this between 75-80 mph.

From what I was able to find out when researching what car to buy (got a 1.9 TDi, 56k, 07 plate) the official consumption figures for the 1.4 and 1.9 are 53mpg and 55 mpg, but this is only valid for restrained driving. When loaded the 1.4 uses more as it struggles with the load, as well as at motorway speeds where it has to run at higher revs. - I have not tested this, but just from what i read in reviews. So due to this cancelling out any savings, plus the negligible difference of 2mpg, i felt the 1.9 to be a better overall option. I am very happy with it, and hope to keep it for years to come.

[Mehitabel]

Thanks for replies. I think I'll soldier on for another year then look at replacing it with a 1.9 when I've saved up a bit. I fancy one of those nice skylights in the 3...

[faradaycage]

I have a 2006 1.4 petrol engined Roomie and the winter average has been 36 mpg,not that impressive considering that my eyes are permanently glued to the Econometer and I drive like an 80 year old nun.Having that ave' fuel consumption gizmo has really toned down my foot to the floor driving style,I find myself obsessed now with bettering the previous runs fuel figures every time.

I'm hoping spring/summer temperatures will see a marked improvement in my MPG.

[Robjon]

Official fuel consumption figures for the 1.4 petrol are:

 

Urban 31.7mpg

Extra Urban 50.4mpg

Combined 41.5mpg

 

For winter driving on mixed roads, your 36mpg would seem about right.

 

Incidentally, welcome to Briskoda

[faradaycage]

 

Official fuel consumption figures for the 1.4 petrol are:

 

Urban 31.7mpg

Extra Urban 50.4mpg

Combined 41.5mpg

 

For winter driving on mixed roads, your 36mpg would seem about right.

 

Incidentally, welcome to Briskoda

Thanks for the information and the welcome,Robjon.I tend to forget how heavy/well built the Roomie is.My other vehicles are a Transit 2.5 diesel and an old racing quad.I moved up from driving an ancient Yaris 1.0 of a weekend to using the Roomster most days now as its a lot cheaper to run than my big old van.

Given those figures above I don't feel too bad about my MPG now.Though I would love to drop in a K&N filter for a little extra oomph,I've never done it in case the ECU kicks up a fuss and starts lighting up the dashboard like a christmas tree..lol

 

[bobspark]

When I first had my second-hand Scout 1.9,at 2.5 years old, it would do minimum 53mpg .Then I gave it its first major service at 4 years old which included a new air filter. The fuel consumption went down hill. Putting another air filter in did not improve things. Illness got in the way untill early last year I decided it must be the mass air flow meter, and mpg was poor at 46mpg.I thought maybe I may have disturbed a fine layer of dust when I lifted the air filter cover up? Even with a 60 bit set of adapters I couldn,t find one to fit the MAF star shaped screws, so took the complete tube out and gave it a blast of compressed air from a can I bought at a jumble sale.Mpg improved.

Mpg started to drop again recently ,so I removed the MAF screws using electrical pliers as a pair of grips on the sides of the screw heads. Gave the MAF a good clean with electrical contact cleaner which I bought at Halfords for about £4.

I then replaced the 2 screws with pozidrive self tappers I happened to have in the garage.

As I only fill up every 2 months its going to be a while till I find out if has improved things. 

[bryanb]

1.6 CR Tdi 2010 here, true brim to brim mpg is 52.5. Very long runs at around 60 mph gives 63 mpg. I ignore the figures given by the computer, but the trend gives a fair indication.

[faradaycage]

 

1.6 CR Tdi 2010 here, true brim to brim mpg is 52.5. Very long runs at around 60 mph gives 63 mpg. I ignore the figures given by the computer, but the trend gives a fair indication.

 Nice figures you're getting there.

[Robjon]

Mine's the old 1.9 PD TDI, which gives similar mpg figures to Bryanb's 1.6 CR TDI but without the complication of a DPF.

 

On the downside, the gruffness of the 1.9TDI is always evident.

And in winter, I have to drive two miles before even warm air comes through the heater.

And my diesel-engined Roomster cost £1.000 more than the petrol-engined equivalent.

 

The 1.4 petrol engine is quieter and more refined than any diesel.

But for me, it lacks the low-down grunt and sheer driving pleasure of a diesel.

And of course, it will never be as economical as a diesel.

 

Horses for courses...

[faradaycage]

Mine's the old 1.9 PD TDI, which gives similar mpg figures to Bryanb's 1.6 CR TDI but without the complication of a DPF.

 

On the downside, the gruffness of the 1.9TDI is always evident.

And in winter, I have to drive two miles before even warm air comes through the heater.

And my diesel-engined Roomster cost £1.000 more than the petrol-engined equivalent.

 

The 1.4 petrol engine is quieter and more refined than any diesel.

But for me, it lacks the low-down grunt and sheer driving pleasure of a diesel.

And of course, it will never be as economical as a diesel.

 

Horses for courses...

Yep,fully agree with all that you've said there,I've had diesel Citroen BX's,Xantias and a couple of Ford diesels along the way,a decently set up turbo diesel is a thing of much joy to drive.

Funny you mentioning your heater though,because the one thing about my little 1.4 petrol is how many passengers comment on the speed of the heater on cold mornings and its ability to go from nought to toasty warm in no time at all.

Edited 24 February, 2015 by faradaycage

[tamiyaandy]

I had a 1.4 Tdi 80 fabia before my current car, and could easily average high 50's MPG.

 

Its the same case with my Touran, Its a 1.9 Tdi PD without a DPF and weighs 1.5 Tonnes, but the long term average still sits at just over 50, can squeeze into the 60's on long runs.

 

Agree 1.9 PD's are a little on the gruff side, but to be fair, the 3-pot 1.4 is not exactly a purring kitten is it!  :no:

[freelanderman]

I have the 1.4tdi, and always manage 50 plus mpg, but shove it over 2500 rpm and the fuel consumption drops off dramatically.

[faradaycage]

I have the 1.4tdi, and always manage 50 plus mpg, but shove it over 2500 rpm and the fuel consumption drops off dramatically.

50 plus from a 1.4 diesel in a car of the Roomsters weight sounds pretty damn good to me.Mind you,I'd have to add how impressed I was by Tamiyaandy's Touran MPG too,the Touran is a pretty weighty beastie.

Edited 24 February, 2015 by faradaycage

[freelanderman]

50 plus from a 1.4 diesel in a car of the Roomsters weight sounds pretty damn good to me.Mind you,I'd have to add how impressed I was by Tamiyaandy's Touran MPG too,the Touran is a pretty weighty beastie.

Like I say keep it at or below 2500 rpm and fuel consumption is good, I fill up weekly and work my consumtion out off the fuel figures. Most of my mileage is motorway miles which probably helps.

[faradaycage]

 

Like I say keep it at or below 2500 rpm and fuel consumption is good, I fill up weekly and work my consumtion out off the fuel figures. Most of my mileage is motorway miles which probably helps.

I live a quarter mile from a dual carriageway,where roundabouts have been breeding in the wild for many moons now,so its rare for me to get a chance to hit and hold a decent turn of speed,but yesterdays out of county trip saw mid forties mpg figures,which made my wallet a very happy camper.

Do you have to "stir the stick" a lot in the 1400 diesel or does it have good mid range torque to keep it up to pace with motorway traffic ?

 

[keystonedriving]

Just as an update to this, over 86,324 miles my 1.4 TDi has averaged 52.27 mpg.  This end of the world is pretty hilly and twisty, so that isn't too shabby.  I do tend to keep to about 60-65 on the major roads as the lower speed definitely helps the economy.

 

If I was in the flat-earth side of the country I would expect to get something in the high 50's.

 

This engine has reasonable torque at lowish revs so there is no need for a lot of gear changing.  It will quite happily pull from 40 in 5th, even from about 35 if you're not in a hurry.  In town there are not to many times you need to drop below 3rd.  A 1.9 would be a bit better to have, but the one I have does the job.

[faradaycage]

Just as an update to this, over 86,324 miles my 1.4 TDi has averaged 52.27 mpg.  This end of the world is pretty hilly and twisty, so that isn't too shabby.  I do tend to keep to about 60-65 on the major roads as the lower speed definitely helps the economy.

 

If I was in the flat-earth side of the country I would expect to get something in the high 50's.

Yep,you get some pretty vicious crosswinds on that hilly section from Launceston to Bodmin too,the wind used to scrub 20mph instantly off my quads speed.it was like hitting a brick wall,lol.Beautiful stretches of road down there though.

[keystonedriving]

Yep,you get some pretty vicious crosswinds on that hilly section from Launceston to Bodmin too,the wind used to scrub 20mph instantly off my quads speed.it was like hitting a brick wall,lol.Beautiful stretches of road down there though.

 

I live just south of Launceston, so I spend a lot of time on that road.  Wind makes a big difference, on a trip to Penzance I got 45 mpg going and 65 mpg coming back.  Guess which direction the gale was coming from!

[tamiyaandy]

Indeed faradaycage, if you Really shortshift it I have seen low 70's mpg come up on an A road to work were its 40Mph for around 10 miles in 6th gear with no stopping, so it just plods on at 1400 rpm.

 

but as stated, in the real world, and without driving like miss daisy clogging up your EGR system, low 50's should come easy.

Edited 24 February, 2015 by tamiyaandy