hdi economy

406 express · Post by **406 express** » Thu Mar 29, 2007 3:59 am

hi guys, over the weekend I was down in south wales, round trip of 400 miles and my hdi 110 only managed 41mpg, it was on single carageway, speeds around 50 - 70, does this seem very low? the car is serviced regularly and is good condition, tyres etc, I am at a loss why the fuel economy is so poor, anyone got any advice on how to increase this? your help please would be appreciated, cheers in advance

neildavies · Post by **neildavies** » Thu Mar 29, 2007 7:47 am

I live in South Wales and last year took a journey to West Wales near Aberystwyth. The route is all single A roads, so I didn't expect much mpg (2.2HDi) but I averaged almost 49mpg over the 200 odd miles there and back and a bit of travelling round while we were there. In complete honsty, I wasn't trying, I drove the car as I would normally, overtaking lots of caravans etc. In fact, I was so impressed, I took a photo! Here it is.

In a recent motorway trip, sticking the cruise control on about 62mph, I got nearly 55mpg. So I think 40mpg is a bit low for yours, but mpg can vary a lot depending on your driving. Also, bear in mind that although my engine is bigger, it might get more mpg on these single A-roads because I might need less gear changes.

Post by **Welly** » Thu Mar 29, 2007 8:33 am

Thats a snazzy looking multi function display neil

I posted on here recently about a 200 mile trip to 'Skeggy'

and I tried so hard to drive economically on those dead flat roads it was stressful

I got 53 MPG in my 110 on that trip.

My daily jaunt to work and back and some running around gets me 37 in the summer and 34 in the winter.

To be fair, every motorway run I've done over distance has always seen 48 to 50MPG

Moos3h · Post by **Moos3h** » Thu Mar 29, 2007 9:44 am

Mine was a terrific 52mpg at the weekend, but this week (doing my usual 20 miles of motorway and 10 of around town daily) has dropped right down to 41.7 - weird.

I put some injector cleaner in though, so perhaps it's getting through that which is causing the economy to be less good.

Cheers,
James

406 express · Post by **406 express** » Thu Mar 29, 2007 10:01 am

had injector cleaner through it, twice!, also the route was quiet so overtaking was at a minimum and any overtaking would olny be dropping down to forth, its really getting on my tits, any suggestions on wether its mechanical or electrical that could be causing the poor economy

Post by **Welly** » Thu Mar 29, 2007 10:39 am

It could be down to simple things like Air Filter becoming clogged, or even your using electrical accessories like the a/c or heated seats etc.

It sounds daft but I use Silkolene oils and they are well engineered products which are suppose to reduce the running drag of an engine, maybe your oil is a thick/general purpose oil?

I have found the HDi to be very sensitive to external temperature, it has a cold start enrichment programme and on short journeys in the cold weather the economy is bad IMO.

Other than this, I suppose it's possible that the injectors are worn? not sure if that happens on HDi's TBH.

mjb · Post by **mjb** » Thu Mar 29, 2007 1:03 pm

Economical driving... I know a bit or 2 about that

1. Speed is bad. I lose 8mpg doing indicated 70mph instead of indicated 60mph.
2. Accelerating is bad. Accelerate as gently as you can, take corners as quick as you dare without braking. Stick to a constant speed as closely as you can.
3. Powered movement is bad. If you think you may need to slow down, take your foot straight off the accelerator - don't wait and then brake. When your foot's off the gas and you're in gear, you're using no petrol at all (may be different on a diseasel but I don't think so). Long downhill section? Dip the clutch and let gravity do its stuff! I get about 5 'free' miles a day this way...
4. High revs are bad. Use the highest gear you can without labouring the engine
5. Slipstreaming is good. If you're awake, an articulated lorry can give you an extra couple of mpg br reducing air resistance. It can also help you steady your speed and slow down acceleration. An arctic's length is a good distance to be behind a truck, but make sure you pay damn good attention to the road ahead where you can.

I average 42mpg out of my petrol turbo doing this on a daily run of 120 miles. The motorway parts of this return as much as 55mpg!

Oh, and check your brakes! If they're rubbing unneccesarily, they'll be causing friction which will drastically reduce economy.

Aircon only really hits me for about 1-2mpg if I have it on 'auto'

neildavies · Post by **neildavies** » Thu Mar 29, 2007 7:28 pm

Welton wrote:Thats a snazzy looking multi function display neil

Had the sat nav on in the background. Normally, the radio display will take up most of the screen and the mpg will be smaller and on the left hand side.

Captain Jack · Post by **Captain Jack** » Thu Mar 29, 2007 7:37 pm

I agree with most of the above, except the speed. Maybe it only applies to diesels though... The best economy on my car is when I do 80mph. Since I have NO money left until tomorrow, I was driving as carefully as I could. Anything from 35mph and I was in 5th gear (about 1200rpm). Managed to get up to 612 miles till my needle hit the orange light this morning - but that was only cos I accelerated in 2nd gear up to 4000rpm (that's a lot on a diesel!), spewing black smoke behind me as some tosser (Audi driver

) was on my arse for the past 5 miles (and also some idiot in a 307 in front doing 40 on a straight road and BRAKING!). Averaged nearly 46mpg from that tank. That's all mixed driving. Normally average 42-43mpg.

mjb · Post by **mjb** » Thu Mar 29, 2007 7:59 pm

Payday for me in a little over 4 hours

First thing tomorrow morning I'll be at the petrol station... putting 69.4 litres in. It's really bad ain't it when you know exactly how much fuel's in the tank to about 250ml! But I am acutely aware of my fuel consumption and how various things (rain, traffic jams, lack of trucks to slipstream) affect my mileage.

Gawd I need to earn more money so I don't have to worry about this sh*t and can go back to hitting 4000rpm in 5th... *COUGH* ;)

CptnJack I'm shocked your car gives better economy at 80... With my estate, wind resistance starts to have a noticeable effect over about 50 depending on the weather

mbell666 · Post by **mbell666** » Fri Mar 30, 2007 12:38 pm

a few months a go i was getting around 52/53 mpg but that has dropped to around 49, but i do have a rubbing brake. hopefully fix that this weekend.

I tend to drive mostly around 70, but i accelerate hard off round abouts (well upto to 3k rpm, this is where the power seams to be on my car) and then keep a steady (ish) speed. I am sure i read/heard i that some "boffins" worked was best to accelerate at about 75%, due to engine efficiently, time spent accelerating ect.

Post by **Welly** » Fri Mar 30, 2007 12:45 pm

I wrote:Thats a snazzy looking multi function display neil

neildavies wrote:Had the sat nav on in the background

Thats a weird looking Sat Nav display neil.

neildavies · Post by **neildavies** » Fri Mar 30, 2007 1:25 pm

If you look closely, you can just make out the beginning of "3 miles" and a road on the left hand side, and then the end of "Merthyr Tydfil" on the right hand side.

Then when you press the wiper stalk(shich I did to tkae the photo), the trip computer takes over the screen for a few seconds.

406 express · Post by **406 express** » Fri Mar 30, 2007 9:10 pm

been exploring the rubbing brakes theory, took the rear discs off and the handbrake shoes where completely fooked, they were shaped like 50p pieces , putting new discs, pads and shoes on tomorrow, let you know how I get on, god bless the haynes manual!!!!

jameslxdt · Post by **jameslxdt** » Fri Mar 30, 2007 9:14 pm

neildavies wrote:shich I did to tkae the photo

and what language is this?