HDi 110 - Poor Fuel Consumtpion

[waue1978]

I'm not too sure if I'm right with this or not, but I've had my X plate HDi 110 estate 2 months now & fuel consumption doesn't seem to be as good as some seem to be getting. The last 200 miles were nearly all cold running short trips & I've averaged 31.5mpg. To be honest, I don't htink it's too far off as the Xantia Hdi 90 I had a few years ago was only averaging about 33-35mpg anyway, but thought it would be worth checking. On a 70-80 Motorway run the instant consumption on the computer only seems to show 45mpg & I would've thought 50-60mpg would be reasonable to expect.

It's running smooth enough with no nasty noises or rattles & I can't find any obvious split hoses anywhere. Performance is adequate although it doesn't have the same oomph that the Mondeo TDDi it replaced had, but the Pug has a bit less torque than the Mondy & has much taller gearing - 4th gear in a 30 limit has her labouring a bit.

The car had a full service last April at 70k (now at 79k) & I'm pretty sure I'm going to need the cambelt changed this year (along with the bottom pulley, water pump & aux belt at the same time) as I don't have all of the receipts for the service history.

[BruceT]

Doesnt sound far out to be honest.

I recon depending on how you drive you can always get 4-5mpg difference compared t someone else.

My misses doesnt drive as smoothly as me but when I make her we can average 53-54mpg in our ladened 90HDi Estate. If its her normal driving then we get 46-47mpg on the motorway

Fuel wise there is not much in it between the 90 and 110 from what ive read into.

On my short commute where the engine coolant needles doesnt even move I average 32-35 on the computer but working it out with fuel top ups and miles coverage and diesel used the onboard computer I find to 2-3 MPG out. ie, if computer says 33 its more realistically 35 etc.

I wouldnt worry too much if that was mine.

Check your tyres pressures
Binding brakes
Fuel Filter Condition

Id leave it there. If will probably get better once it warms up too.

[Welly]

To be honest when it's really cold out (as in the last 3 months it seems) then the HDi does suffer as much as 4-5mpg due to it's cold start enrichment programme and the fact it takes weeks for the engine to warm up fully.

One thing to check is the tyre pressures! I gained 2-3mpg when I realised the tyres should be run at 33PSi

Different Diesel fuels don't seem to make any difference.

Turn off the a/c (you don't need it in the winter, the air is 'dry' enough out there to demist windows properly).

Other than that make sure the air filter is clean, or just change it anyway (for a Dealer proper one).

Driving style is a biggy - try to look wayyyyyyy ahead and keep off the brakes.

Welly

[waue1978]

That's a bit of a relief then. Although I thought I had been driving pretty steady for the past few weeks anyway.

Had a motorway run to Southampton & back yesterday though & actually found it was running better on the way back at 80ish than it did on the way down at 70!

Might have a look at that EGR at the weekend. Anybody got any pics or know where I can find a How To guide?

[DiscoPol]

Tyres Tyres Tyres,
the biggest difference for me is those buggars it makes a good 5-6 mpg difference if you have just one down a bit.

after that blame these cold days its ruined my consumption on shorts runs and I really try to keep the mpg up, as a guide Im getting an average of about 53 mpg at the moment and thats combined 60/40 m-way and urban, but as my wife will tell you Im a real pain in the arse when it comes to driving style

so the usual checks as mentioned above:

tyres
filters
brakes
Air-con
service??
driving style

but doesnt sound to awful tbh, wait a while till it warms up and then monitor it over a month or so.

HTH

Dan

[jasper5]

My 90 HDi Expert van has dropped from 290 miles to 40 quid of diesel to 240 miles, doesn't need servicing, I'm convinced it's a combination of the recent price rises and the very cold winter.

[plod]

I reckon I get about 41mpg out of my 110 HDi but it's been remapped to 140bhp

[steve_earwig]

Worth lobbing a tin of (cat friendly) injector cleaner through it?

[Littlelad]

Hi
I agree with other comments especially the slow warm up - typical of any diesel. An often overlooked detail is the engine oil viscosity for colder climates. ideally 5w 40 fully synth is better for the weather we've been experiencing - it's not difficult to understand how hard it is for the motor to squeeze thick oil around the system. This takes a lot of fuel especially if your only doing short runs. A reassuring easy check for other possible faults is when it is up to temperature put a clean white cloth over the exhaust and give it a few good blips on the accelerator and see how dirty the cloth gets. HDi s in good fettle a very clean at the exhaust. Or gets someone to watch the tailpipe as it is blipped - should be at most just a slight trace of grey. I get 50 - 60mpg easy driving on motorway 40 Urban cycle when warmed up. If I wanted to be a pain in the neck to others I could get 65mpg on motorways.

[hammerman]

I reckon I get about 41mpg out of my 110 HDi but it's been remapped to 140bhp

Mines remapped too to 140 bhp.Coming home today from Shrewsbury to Bristol,M54,M6,M5,126 miles,loads of traffic,then 85 on the cruise(sticking to the speed limit wink)my computor averaged 47.4mpg.
On mixed town work i get around 40 mpg,& towing our caravan i get 30 mpg.

[waue1978]

I've been toying with the idea of getting one of those tuning boxes that whacks the power up to about 130-140, but reckon I'd be best waiting till after I've done the cambelt & service.

The Mondeo & VW owners say that their clutch/flywheel never lasts too long after fitting a tuning box. Is this something to worry about with a 406?

[Welly]

Is this something to worry about with a 406?

Yes, it's even something to worry about with a standard 406

[steve_earwig]

The usual response is remap yes, tuning box hell no.

[Littlelad]

I could not agree more - any attempt to modify a standard engine mapping is foolhardy unless you know what margin loss will be on crankshaft and pistons. One thing is certain if you use the extra power assuming this has been verifyed on a rolling road of somewhere around the claimed increase of 30bhp expect to reduce the life by 25%. The power increase is translated to pressure on the main bearing cap bolts which will stretch and fracture. Not to mention the side wall pressure on the cylinder wet liners which can cause leaks at the head and base seals. Then there is the infamous Dual mass flywheel - say no more. PS the D10 ATED HDi 110 was already modified from an earlier version just to accomodated this output.

[hammerman]

I had mine remapped 3 days after i git it in oct 2006 at 57k miles.I`ve now clocked up 120k miles,still with the original clutch & flywheel.I do a lot of caravan towing with it & so did my dad when it was his company car.I reckon i`ll be needing a clutch by the end of this year.
When i left Shrewsbury yesterday on the A5 at the traffic lights,i was in the outside lane,with a new 59 reg Honda Accord 2.2 diesel beside me(150bhp i think)As we pulled away from the lights,he floored it,leaving clouds of black smoke.So i floored mine.I managed to keep up & over take him .Dont asked what speed we were doing.He looked a bit gutted when i went past.So the remap works well on mine,no issues with it,with good reliability & fuel economy,serviced every 10k miles with 10/40 semi syn oil.
I gained a few mpg after the remap too.