Mpg issue

[dreddfan]

I've been having trouble with the mpg on my 06 1.9 Tdi ANU Sharan.

When I'm doing 100 Kph at 1900 Rpm I can see the fuel needle visibly dropping. I know that I went from a 1.9 AHU A4 B5 to the Sharan which has a bigger, less aerodynamic body etc but this is costing me a good bit on fuel and it needs fixing as I do a 110 km main road round trip commute daily.

I've removed any dead weight including the rearmost back seats (surplus to requirements at the min) and I drive conservatively in as high a gear as possible to keep revs down. I have good quality new tyres on the car.

I've cleaned the intake manifold and EGR (and managed to crack the plastic pipe going from the air box to the turbo in the process, next thing on the list to fix :mad:) which were quite dirty but not as bad as I expected and fixed a split in the top pipe on the EGR and this has improved the mpg a little but is there anything else I can do to improve things?

There's a reputable chipping company local to me who can do the job for 250 Euro but I'm a bit iffey about going down that road purely for fuel economy reasons as I'm not really after a power boost but they tell me I'll get improved Mpg.

Does anyone have any suggestions on any other things I could do?

Thanks,

MS.

[Eshrules]

How are the brim>brim comparisons looking? IE, what are you getting on this one compared to the Sharan?

[DaveJFT]

Hi MS,

Are you able to check for fault codes stored in the ECU? I believe a MAF meter fault can cause high fuel consumption through misreporting the inlet temp or air flow rate.

I, myself, have a query over whether my faulty coolant temp sender can have a similar effect through fooling the ECU into thinking the engine is stone cold and needs extra fueling.

The ambient temp sender has a big influence over when the diesel fueled auxiliary heater runs too.

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[Doctle Odd]

It's never going to get near the MPG of the A4 Dredd it's basically a really heavy shed on wheels

[DaveJFT]

...but what is classed as not getting near it? I've had my 96kW ASZ engined Bammer since 2004 and I've religiously kept complete logs of fuel consumption since 2009 covering over 160,000km. My average since my records began is 6.3l/100km which I think is pretty respectable for any large family car and especially one that's getting as long in the tooth as mine is.

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[dreddfan]

Hey Doc, I realise its never going to compare to the A4 but where 50-60 euro did me in the A4 I'm looking at at least 100 per week for the same driving. One of the lads here has an 03 Galaxy and he necked it on the far side of germany and got to Dungarvan on one tankful. I can physically see the fuel gauge dropping as I drive along.
I'll get it plugged in asap.

[Doctle Odd]

There's a guy near here with a galaxy it averages under 40 mpg. Diesel has gone up a little again 151.9 here which is mental. you deffo need a scan tho

[dreddfan]

Ok, got it plugged in and no codes at all stored.
I have cleaned the MAF sensor (with the correct stuff) and will try it out later. One thing I did notice is that my MAF (part number F 00C 2G2 055) doesn't seem to have the temp resistor visible on it but I've looked up pictures of it and some have it while others don't. I know the MAF on my A4 didn't have one but can someone tell me if it's fallen off?
22737

[Eshrules]

Cleaning MAF sensors rarely works - if you consider the part to be faulty, you really ought to replace it.

[Doctle Odd]

I had a look on parkers the seem to be averaging lo 40's for MPG even the higher BHP models. Maybe a remap or tuning box might help? ANU at 90 brake seems underpowered for that IMO

[dreddfan]

Any idea what kind of improvements I could expect from a remap? Prob hard to know without actually doing it i know but has anyone actually done a remap on this engine?
As to my original question, should this MAF have the external temp sensor?

[Doctle Odd]

As far as I know you can get a remap for economy as well as bhp. Some people swear by tuning boxes might be worth a try as you have 14 days to return them and they're cheap. They say 10-15% more mpg in reality 4-6 miles. If you try a tuning box maybe you could do a report on any benefits? Not sure on the MAF temp sensor

[dreddfan]

I'll have a look around and see whats out there in the line of a tuning box (site sponsers first of course)
I know a remap is 250.

[Doctle Odd]

There's guys round here doing a remap for 200 yoyos I wouldn't allow them to get into my boot. copied maps, usually on the roadside no landline number etc.

[dreddfan]

I've cleaned the MAF and seems to be a little better. I put 40 litres in the tank this am and zeroed the clock so we'll see how far that takes me so I'll have some accurate mpg figures to work off.

[Doctle Odd]

Keep us posted Dredd I don't think the MAF cleaning does much to be honest

[dreddfan]

I've been watching the needle as I drive to work and it has barely moved since I cleaned the MAF whereas it used to drop like a rock so I'm hopeful it will be a success. I'll post my mpg when I need refilling again. I've a good bit of driving to do this weekend so that'll test it.

Any idea what mpg I could expect from the Sharan??

[DaveJFT]

It really does depend on the type of roads and style of driving you have. I'm not a speed freak, I mainly sit behind free flowing traffic on motorways and and I average 6.3-6.4l/100km (44-45mpg) and that's with the 130TDi engine. Town roads, roads with lots of roundabouts and lots of corners tend to drop my mpg to ~39-40mpg. The Sharan is a heavy car so constant deceleration-acceleration takes a heavy toll.

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[dreddfan]

Most of my driving is main road 100Kmph with little traffic or Motorway 120Kmph so I'd be hoping for 40ish. Thinking seriously of a remap at the min to get it up to 110 Bhp and better fuel economy.

[Doctle Odd]

Sharan, Galaxy and Alambra seem to average 43MPG. I know it's not recent data but I looked on Parkers.co.uk and all the diesels seemed to have the same average regardless of horsepower.

[dreddfan]

Well the results are in:
38 mpg after cleaning the MAF and it seems to be behaving itself. 650km on 47 litres of diesel and that was two runs to work (100kmph main road) and two motorway runs with a very heavily laden car (family, all our stuff, 80kg of coal and 2 full gas cylinders. That'd have been an interesting one for the fire brigade if we'd crashed)
I'm happy enough that I'm back to where I should be as regards fuel economy but the remap is still a good possibility to improve it.

[Doctle Odd]

650 km on 47 litres is 62 MPG. Thats impressive in most cars :)

[DaveJFT]

650 km on 47 litres is 62 MPG. Thats impressive in most cars :)

Doctle,

Don't forget to convert the km into miles too - it works out at 39mpg.

:)

Dave

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[Doctle Odd]

maths was never my strong point!

[dreddfan]

I got a new MAF sensor yesterday coz the cleaning didn't last long but at least it proved where the problem lay. More power, higher mpg and a lot more poke in the engine.
Now on to the next problem, the Auxilary heater with a suspected dead glow plug!

[DaveJFT]

Been there, done that too! There's a guy near me who builds these into boats. I gave him mine and he did a complete strip down and rebuild -new gaskets and some gauze thingy - and a full bench test before refitting it and vehicle testing it. Not cheap at 270GBP but well worth it. It's never run so well.

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[OC-K1NG]

I had same issue with mpg, and thought what the heck and brought a £17 plug and play thing off ebay to give me more power and better fuel ecconomy... and hey it worked :) eBay ID 271497998930