Car only does about 400 miles to full tank

[om4r2203]

Hi. New user. Just like to say hi to all on the forums

I know this has been discussed before but couldnt really find an answer. I have used my car for the last 3 months now and i have never gotten over 400 miles. that is with 70% motorway and 30% local. I had a honda diesel and used to get 500+. I have had it fully serviced, cambelt done. Its at 65k now.

Is there anything you can recommend. My driving style is ok. not heavy footed. Would a re map make a difference to this.

I have tried both v power and normal fuels which make no diff what so ever.:aargh4:

[SunnyBard]

Hi. New user. Just like to say hi to all on the forums
Welcome


i have never gotten over 400 miles

You might get sensible replies if you told us what engine/gearbox you've got ...

[om4r2203]

Hi

Sorry i have a 2008 Audi a4 2.0tdi 143, it has a 6 speed manual box

[Eshrules]

tank capacity of 65l, quoted fuel economy of 53mpg - so assuming you see around 45mpg on average, you should be getting at least 650 miles to a tank.

It's not fair to compare to the 'honda diesel' as we know not it's model, engine, power or fuel tank size.

What MPG figure does your trip computer display for the average readout?

[om4r2203]

Hi

The honda was 2.2 cdti diesel. 5 speed box manual and had a similar fuel tank
The trip shows me 38.7 is my avg. i expected the car to give me more say about 500 atleast... when i fill up full tank to the brim it shows a read out of about 540 miles but i never get any where near this

Even at my avg i should be getting over 500 miles

[Sam]

~400 miles on a full tank (65 litres) is just under 28 mpg - something is very wrong.

[om4r2203]

Any ideas what it could be tho??

I have had a visual inspection of the car no leaks no smell of diesel in the car. runs smooth no errors on the system and no funny lights on the car

Its got me baffled

[xtremist]

I have the same engine and it's done about 55k. I get between 500 and 550 to a tank. This would suggest something is up with your driving style or car.

If i only got 400miles to a tank, i'd be looking for a new car.

[om4r2203]

i dont think my driving is too bad. what do you reckon could be wrong with the car. any sort of things i can check. its had a full service inc all filters and timing belt done with tensioners and water pump last month

[kite]

Was the fuel consumption better before the cambelt change, could the timing be slightly out?

From a phone that's smarter than me...

[om4r2203]

i would say its the same. if the timing belt was out i probz would have noticed due to it being faster or more sluggish than before

[kite]

Have you done a brim to brim check on your MPG. Don't trust the DIS.

From a phone that's smarter than me...

[kodkod.84]

From my 2.0tfsi petrol I was getting anywhere between 30-35mpg- are you getting 400miles from the 'range' computer or is that from the trip computer and a full tank?

[Sam]

When you next see your refuel light, fill the car to the brim and make a note of how much fuel you've put in the tank.

Zero the odometer and drive as normal until your refuel light comes on again, make another note of the mileage and manually calculate the mpg.

It wouldn't hurt to have the car scanned for faults too.

Have a look in this section (http://www.vwaudiforum.co.uk/forum/forumdisplay.php?257-VCDS-Users-Locations) to see if there's anyone local with VCDS who can scan the car for you.

[om4r2203]

I have just fuelled up to the brim. The mileage i was getting was from the odometer of what i actually done on a full tank. i have reset all to 0 checked tyre pressure and we shall see how it goes. I did have the vcds done and there was no faults showing at that time. this was lest than a month ago.

Lest see how we get on now. Is there any fuel additves you can recommend to clean the system

Thanks for all the help guyz

[kite]

Forte additive gets good reviews

From a phone that's smarter than me...

[OVI82]

I've used Millers diesel treatment and found it ok.But even with the best diesel treatment you won't get another 100-150 miles to a tank.you can try it but but I doubt it will help that much.

[adamss24]

Fuel additives are just red herrings ! If 1500 bars of pressure cannot clean the injectors what make's you think a magic potion will ?! The way fuel additives/cetane booster work is by retading the timing which in turn effects a more complete burn which - as a placebo effect- makes the car feel faster(the engine get's quieter as well which adds to the feel) ! The engine labours less so the torque threshold moves a couple of hundreds rpm's lower on the power curve...You will get a couple of mpg increase as the fuel burns more complete but don't expect wonders from a few teacups of kerosen mixed with petrol !

[The Polisher]

Same car as me (manual 143tdi) and I never get less than 600 to a tank. After a fill up the computer always goes between 610 and 650. Even with 105k on the clock, still just as good.

I'd say you have an issue, best head to the dealer me thinks!

[JimC64]

Hey there, sorry I can't help too much on the issues but I'd suggest you deffo have a problem.

I have an 07 plate 2.0 tdi remapped with a boot constantly FULL of all sorts of stuff, my daily drive has went from 98% motorway to nearly all stop / start and around town these days.
I'm really annoyed to be getting around 38mpg and around 500 miles to a tank of fuel. Even at that I'm sure I could go further, let the light stay on and get another 50 miles out of her to get me 550 total.

The best I ever had was just shy of 700 miles on a long and careful run, eventhen I reckon there was another 50+ miles left in her, and this from an older A6.

As others have said you definitely have an issue, but you obviously know this.
I really hope you get it resolved sooner rather than later.

[rd1]

I have the same car as you and like others get between the 500-550 per tank depending on the driving I do. I'm sure your problem is mechanical but along with the other tests do you use the recommended gear change light on the dash, if not perhaps try it for a tankful of fuel to see if your mileage increases. Probably not so much fun though!
Good luck, hope you resolve whatever it is

[om4r2203]

Hey thanks for replies

I have fuelled up and trying to drive like a bit of a miss daisy and yes i am using the suggestive gear changes.
When some ppl say that i may have a problem any idea where you think the problem will lie??

[om4r2203]

On another note the peeps who get 500-600 to a full tank whats your driving style like

[JimC64]

My A6 - If I was to really thrash it all day long and every trip i reckon I'd get around the 400miles mark or thereabouts

I'd say my normal everyday driving style is relaxed, generally a little over the speed limits in most cases, with smooth gear changes, no red stop light racing etc etc with the occasional "booting it" thrown in when I either get the urge or there's some really good driving music on the radio.

When I achived nearly 700 miles to a tank with approx 50+ left, I wass more or less "hypermiling" the whole way.
I drove at around 70mph on cruise and it was 95 % motorway miles, I was careful not to brake unless absolutely necessary, took off smoothly, neutral going downhills etc etc. I did stop short of the following - turning the A/C off ( supposedly worth around 5 mpg ) radios off , windows not open even slightly for wind resistance, emptying the boot etc etc.

It was tiring to say the least to have to actually "think" that much about your driving for the whole time....when I filled it up again, my DIS said *** 915 miles range ***
Here's a link to a thread I made about it you might find interesting

http://www.vwaudiforum.co.uk/forum/showthread.php?73837-A6-2.0-TDI-Mileage-Glasgow-to-London-AND-back

good luck my friend :beerchug:

[gregpot2000]

I'd be very interested to hear any solution to this, I have exactly the same car, and the same problem. but slightly better, I get around 440-460 miles
Although I never thought it was a problem, and just normal? as most of my driving is town driving, with the occasional motorway journey of 30 miles there and back every couple of weeks.

Always presumed if I was doing all motorway driving I would get the DIS amount of 520 after filling up

[Sportingmac]

You can only do 'tank to tank' and calculate on miles done - ignore any DIS readout, it is usually too optimistic - by a long way. If you want real world figures go to Honest John website and check what people are recording - it shouldn't surprise you to know that the average is generally 5~10 mpg below official figures.

[Guest 2]

What size of tank is in the a4?

[chody]

65l as already mentioned

[gregpot2000]

sorry, I probably didn't make myself clear, I reset the trip computer after every fill up, and my figures are from that

[theskyfox]

Until recently I was lucky to hit 400 miles to a tank in my car. Was only when I hit about the 9,000 mile mark that I actually started to get 400+ to a tank. My current record is around the 450 mark. That is without the fuel light on though...the needle dips so low I start to sweat and wonder if the low fuel warning is even working lol...

-Andrew

[SunnyBard]

65l as already mentioned

Even having driven on fumes for about 20 miles, the largest fill-up I've had was 60l ... the longest actual range I had between fill-ups was 440miles, but taking the range of my most frugal fill-up, and adjusting for the total 65l, suggests I could get 493 miles before running dry ...

[jakerade]

have a read of this - probably not good news if out of warranty although there are people who can clean dpfs

http://www.pistonheads.com/gassing/topic.asp?h=0&f=86&t=919184&mid=112736&i=0&nmt=Skoda+Octavia+CR+vRS+-+Fuel+economy%2FDPF+problem%3F&mid=112736

[markp306]

I have a 2.0 143 which is used mainly for urban journeys, including many short local journeys such as school runs by the wife. It also gets some short (35 mile) motorway runs, so the mileage is probably about 70:30 urban to motorway. I haven't really studied the mpg closely as I bought the TDI for overall driveability to replace a petrol 1.8T. I also studied the urban mpg figures when purchasing as I think this is your real world number in todays traffic conditions, unless you honestly do spend all your time on a motorway doing long journeys.

The second trip computer (never reset) shows an average of around 37+ mpg which probably ties into the 450-ish miles I get between refills ("please refill" comes on at 55ltr/12gal)

The first trip computer regularly shows 40+ mpg journey averages and will show 50+ on a motorway run when staying around 70mph. As it happens I have driven more motorways miles on the current tank this week-end and am at just over 260 miles for an indicated half tank. Thats still no more than an estimated 43mpg, but we all know the second half of the tank "goes quicker", so I'm still not sure I will see 500 mile range. Is the DIS lying to me? It does seem odd that the primary trip computer will regularly show journeys of 40-50mpg and yet the tank never gives me 500+ miles. Maybe I'll mention it at next months visit to Audi and see what the "experts" say. I just put it down to too many short and/or urban journeys, but I still take comfort knowing that a petrol can't get anywhere close to this under the same conditions. The previous 1.8T would do about half the mpg of this TDI, requiring fill ups at 250 miles. It was a quattro and had a quoted urban of just 21mpg.

My commute-to-work car is a "65mpg" smart fortwo ;) with stop/start that averages the wrong side of 50mpg for a 16 miles cross-country journey. Thats all it is used for. The best I managed was 54mpg across a 5 gallon tank. I have no idea how they got it to return 65mpg! It certainly wasnt using my commute! :aargh4:

So, I am not sure if there is anything wrong. It just down to driving conditions and each of our individual journeys. I live on the Berkshire/Surrey border and it's just one queue after another around here.

[markp306]

I filled up at 1/4 full and calculated 37mpg again! Doh! I know I can see 47+ mpg average on the DIS for a typical motorway journey and 27- mpg on a short local journey in town, both from cold. The last tank average consumption matches DIS computer #2, so the cars typical journey mix might be 50:50 ish!

Thanks to panic buying last week there was only "super diesel" or whatever BP call it at the garage, but I filled up anyway. This weekend alone I have managed 120 miles of mixed A-road and M-way journeys and the needle is now about mid-point between full and 3/4. Had to conscientiously stick to speed limits and accelerate gently.

Anyway, as mentioned before, it must be the type of journeys (ie school runs and shopping) that drag this number down, although I will question it when the car is in Camberley Audi on Wednesday.

So, any 2.0TDI drivers getting better than 37mpg for a true mix of urban/M-way driving?

Incidentally, that BP diesel was 154.9/ltr :aargh4: The car drives smoothly with it, but I am not expecting any mpg gain. Or should I?

[SunnyBard]

I filled up at 1/4 full and calculated 37mpg again! Doh!
Incidentally, that BP diesel was 154.9/ltr :aargh4: The car drives smoothly with it, but I am not expecting any mpg gain. Or should I?

For obvious reasons i've been eeking out the diesel lately, the normal range on the DIS after a fill-up used to be 450 miles, the last two fill-ups have shown 485 miles, going by mileages and receipts, it's still only nudging 36mpg rather than 33mpg

As for the "super" diesel, I think the car has no way of knowing it's drinking higher cetane fuel, so it won't adjust anything to suit the fuel, I give mine the occasional couple of tanks of it, maybe it helps clean the engine, maybe it just helps clean my wallet:D

[JimC64]

Its definitely the stop / start and around town nature that really eats into your mpg.

I used to travel 50k - 60k per year and in the latter years did more than a few ( mpg runs ) where I filled it, drove it very steadily and measured the mpg via DIS as well as manual calculations.
I found I could be doing really well and perhaps at around 49 mpg, sometimes more and having travelled a long way, really did my average some good, then BAM....
I'd hit a major traffic jam and could be sitting there for hours sometimes. The first ten minutes or so may not be a problem but then watch your mpg fall seriously fast!!

Having done mostly motorway miles my cars average was around the 45 mpg mark and then I started travelling mostly in stop / start conditions around town. The average steadily started to fall and I struggled to keep it in the 40'sbut then it dipped into the high 30's............now with most of my miles being city miles and driving very carefully I can manage around 36.6mpg

[om4r2203]

Hi

Just to update this thread.
The actions i took was i filled my car put some forte in to it and thrashed the hell out of it. Just to burn fuel and clear the DPF. After that i reset onb aord computer 1 and then drove carfully but not like miss daisy and now i can report i can get 550 miles out of a tank. When i fill up the dis shows 610 miles. I have done 2 full tanks and montiored and i am getting 550 - 600 niles to a tank. That is siwth 70% motorway. Just to clarify i do not dive like miss daisy and do anout 80 on motor way but keep my foot steady.

Thanks for all the tips

[jakerade]

sounds like the DPF needed a regen - there are particular conditions it should do it under

[Eshrules]

I'm pretty sure giving the car a quick thrash doesn't invoke a DPF regen cycle. I was under the impression the car had to satisfy certain criteria for a certain period of time before the DPF was regen.

Could be wrong (!)

[jakerade]

I assumed a whole tank of diesel had been used rather than a quick thrash?

I have heard conflicting advice on what point it invokes regen. Local dealer said about 1800 rpm, rosstech shows 2000-2500 rpm


Interesting stuff here

http://www.myturbodiesel.com/1000q/DPF-Adblue-FAQ-VW-Audi.htm
http://www.myturbodiesel.com/1000q/vw-jetta-tdi-golf-dpf-filter.htm

[om4r2203]

When i thrashed it it was on about half a tank and i did thrash it on the motorway doing about 100-120 and running through gears to about 4000 rpm

[Eshrules]

When i thrashed it it was on about half a tank and i did thrash it on the motorway doing about 100-120 and running through gears to about 4000 rpm

two things.

1) should probably stop doing that, you're close to the top end of your engine, never a good thing to be putting it through
2) should probably stop making such declerations on a public forum - you'd be amazed who we have on board.

[om4r2203]

Soory i should have said that is KPH.......;)
I only did it the one time just to clear antyhing in the DPF due to the problems i was having and after that it has been fab... Smooth as anything...

[C Mitchell]

Will try this myself as I am only getting 37.4mpg on mixed driving in my 120bhp tdi. Very disappointed so far.

Keep us posted if things go back or the improvements continue. I tried a quick 15 mile stretch at 70mph in 4rth gear to see if it forced any cleaning issues but no change. I've got 140 mile round trip tomorrow. Might see if I can get that Forte stuff but I won't blast the car as the wee one will be present.

[om4r2203]

I have to say one thing though to get the best out the car you have to keep a steady foot. On motorway keep to a constant. dont matter if its 70 or higher. obviosuly the slower you go the better.

I dont know if blasting the car did help but after reading members comments i thought i would just give it a go and i have to say i have been pleased with the results so far.

[jakerade]

i think you have to keep it under 2500 rpm or it wont regen - i think 2100 is fairly optimum

[markp306]

Interesting stuff here

http://www.myturbodiesel.com/1000q/DPF-Adblue-FAQ-VW-Audi.htm
http://www.myturbodiesel.com/1000q/vw-jetta-tdi-golf-dpf-filter.htm

That explains why the fans continued running the other day. Thanks!

[om4r2203]

I thought the dpf had to reach a certain temp to regen which could only happen at a high rev

[jakerade]

from ross-techs site for emergency regen (slightly different i believe)

Regeneration while Driving
Prerequisites (General):
Ignition ON
Engine ON (Idle)
Coolant Temperature above 70 °C (see MVB 002.4)
Particle Filter Load below Specification (see MVB 108.2/3, VCDS should give the specified values)
If the Particle Filter Load is above Specification the Particle Filter needs to be replaced since the car may burn down when regenerating.
If the Particle Filter Load value in MVB 108 is blank, use alternate group 241.2/3 instead.
Power Consumers ON (Light, Seat Heating, Front/Rear Window Heater, Climate Control)
Engine Hood Closed
Conditions (Driving Cycle):
Vehicle Speed above 60 km/h (40 MPH)
Engine Speed between 2000-2500 RPM (4th or 5th Gear, Automatic Transmission in Tiptronic)
Duration approx. 10-15 Minutes
Exhaust Gas Temperature before Turbo Charger above 170 °C (MVB 099.2)
Exhaust Gas Temperature before Diesel Particle Filter above 150 °C (MVB 099.3)
Exhaust Gas Temperature after Diesel Particle Filter above 150 °C (MVB 099.4)
Drive the car based on the above Conditions until the Particle Filter Load is as low as possible (close to 0 %). In case the Regeneration fails there can either be problems with the Driving Cycle Conditions or with the Engine Hardware.

[Select]

[theskyfox]

Just a few cents...

I've been using a Kia Ceed hire car for the past week. Its a brand-new car (less than 1000 miles on the clock), 1.6 Eco-diesel with no turbo. Its only been me and one other guy in the car. Looking at my fuel consumption just for yesterday...burned 15.27Litres over approx 145 miles. This works out about 43mpg. Driving has been entirely motorway/A road...and im sure there has been a DPF regen in there too.

An A4 is a much heavier car and a bigger engine with turbo...

-Andrew

[A6+A4]

First post - please be gentle!

I've been looking at this thread with interest, especially the DPF regen part since I've also got the same mpg issue in our A4 2.0 TDI (auto) with about 68k on the clock.

According to the DIS, I'll usually average about 41.5 now on my regular commute of 35 miles each way on A&B-roads with a bit of dual carriageway thrown in. With the fuel 'crisis' I did a Miss Daisy/'hypermile' commute a few times and got an average of 47 mpg, twice. I tried it again though and got mid-40s. The only difference in journeys I could tell was the amount I braked to a complete stop at roundabouts and lights.

On the same journey though, driving the same way as normal in our A6 3.0 TDI (with about 100k driven, also an auto), I'll often get 36.6mpg or worst case 34.4. The A4 is not half as much of an improvement in mpg on the A6 as I thought it would be when I bought it, but the dealer checked it out, said it was within normal limits and gave me a sheet of patronising advice on driving style to shut me up!

[Hollywood1984]

It's just a thought, could it be a mechanical problem? And tyre pressures? An old car I had was doing significantly less MPG than I'd hoped for, but it was due to slightly binding brakes, had them cleaned out and serviced, with tyre pressures correct, and it made over 10 MPG difference. My A6 is doing a lot less to a tank than it should so the first thing I'm going to check is brakes.