Mpg getting worse!

ITBarbie · Post by **ITBarbie** » Wed Oct 20, 2010 5:14 pm

Hi

I was mostly getting 23-24mpg on my 2004 3.0d but for some reason recently I'm lucky if I return 21.7! Got it about 18 months ago and one green bar left before service.

I have it booked in with Jason on Sat for a remap and possibly a software upgrade on the gearbox. I read earlier with interest the correct method on checking the actual MPG but have been lazy and not done it so it could be a simple misread.

I would be interested in peoples opinion on getting it on early for the inspection 2 or indeed any other input? Or shall I just leave it to our resident guru Jason to have a look at? It's on approx 71k mileage at the moment.

Penny

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g60renshaw · Post by **g60renshaw** » Wed Oct 20, 2010 5:36 pm

Don't know the ins and outs of the diesels, but I get an indicated 22 to 24MPG out of a 4.4 so something isn't right. Get that at 60p a litre now too with LPG

I would get it in to Jason and anything obvious will be flagged up on the diagnostics.

Jay

5hep · Post by **5hep** » Wed Oct 20, 2010 5:49 pm

Penny

That does not sound good. I drive mine quiet hard split between 50:50 motorway / stop start.

Before Jason remapped my X I was getting 25mpg but now it is showing 28.5mpg.

Any excuse for a remap

Raj · Post by **Raj** » Wed Oct 20, 2010 10:35 pm

See what J thinks, but you may find also that after the inspection II the fuel economy can improve.

Having said that, my M5 was getting very poor mpg (more so than you'd expect....lol) and it turned out to be a very small hole in the servo causing an issue. Replaced under warranty and my mpg went up to nearly 19mpg.

Jalf · Post by **Jalf** » Thu Oct 21, 2010 11:03 am

I'm getting 27 to 28mpg at the moment from mine, I'd say something needs looking at.

ChrisLux · Post by **ChrisLux** » Thu Oct 21, 2010 11:12 am

Something doesn't sound right !!
My '05 3.0d is showing indicated 28-29mpg on the OBD on mostly town stuff .
And my 4.6 V8 Alpina is 22/24 mpg worked out by the full tank/odometer calculation .

Good luck
Chris

Waka · Post by **Waka** » Thu Oct 21, 2010 12:55 pm

Have you changed where you get your fuel recently?

fenj66 · Post by **fenj66** » Thu Oct 21, 2010 2:05 pm

i would make sure the air filter gets replaced, that could affect the mpg if well clogged up. its a particular fiddly job to change on the diesel and could have been skipped last service.

Chompers · Post by **Chompers** » Thu Oct 21, 2010 3:13 pm

Good point Fenj, also get the airbox thats houses the filter cleaned out as well, you'll be surpriced at the amount of $hite that can build up in there.

Penny, what sort of motoring have you been doing, say for the last 500 miles or so? if mainly local running around, it may be worth giving it a good trash down the A23/M23 to clear the exhaust system out, put it in sport mode and take the revs right round to the red line, keeping within the speed limits of course

also carry out a few full throttle bursts and check what comes out of the exhaust. Clearly this should be done when the engine has warmed up and a prior check of the oil level is a must. Have you checked your tyre pressures recently if on the low side, this can affect mpg also are you carrying anything extra in the boot weight wise. All factors that can impact on mpg.

I'm sure Jason may be able to shed more light on things for you, just my 2 pence for what its worth.

ITBarbie · Post by **ITBarbie** » Thu Oct 21, 2010 10:51 pm

Hi

Thanks so much for the replies. In the last 500 miles it has been on a mixture but predominately town driving but it does get a motorway hit at least every 10 days or so. I certainly don't thrash the living daylights out of it but am partial to cleaning out the carb on a run when the mood takes me.

I will pop it into Jason on Saturday morning and will probably get it in for it's inspection 2 early. Already thought about the airfilter change. Might have to tap up my dad for that one. A child always needs to remind their dad he has a purpose

Thanks people. Can't wait for Saturday.

Penny

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philip600 · Post by **philip600** » Fri Oct 22, 2010 8:52 pm

Hi Penny,

My fuel consuption got worse recently, not by much but worse all the same.
I put it down to the colder weather but was also wondering if the webasto heater may make a difference now it's colder.
You may remember I was having problems with mine & still haven't sorted it so at present the fuse is removed.
I wondered even though the heater uses fuel to operate whether this was cancelled out by the fact the engine would warm up more quickly ?
The other thing i did a few weeks ago was to perform a reset on my auto box, this has made a big difference to the gear change, much smoother now on both up & down shifts, but I wondered how much effect it may have on fuel consumption.
Mine used to be around 25/26 MPG, but now done to 24/25
I'm also going to get Jason re-map so would be interested how your's is afterwards.
I'm going to alton Towers tomorrow so that should give her a good run out ( approx 280 miles round trip ) Will see what comsumptions like then.

Kind regards, Phil.

ITBarbie · Post by **ITBarbie** » Fri Oct 22, 2010 11:47 pm

Hi

I will let you know how I get on. I have used my webasto twice so far this year and it's my understanding that it does use your diesel but should have no affect on the mpg. Re the cancelling out again it's my understanding it just warms the cab not the engine so can't factor that in either.

Penny

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AW8 · Post by **AW8** » Sat Oct 23, 2010 12:24 am

I speak from google & forum experience rather than from being a mechanic but MAF sensor, breather & EGR valve supposedly crtitical for best running & mpg.

pvr · Post by **pvr** » Sat Oct 23, 2010 10:11 am

That is an awful mpg though, I am in the low thirties in town. I do tend to drive progressive in town as in looking ahead a long way so avoid any sudden breaking.

Love the reference to a carb though

petert · Post by **petert** » Sat Oct 23, 2010 2:13 pm

My, that signature font colour is a little assertive early on a Saturday morning!

Peter T

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