C3 Mpg?

[citroen_c3_hdi]

Hi, I've just bought a c3 2008 92 bhp hdi fully standard, I'm currently getting (so the internal computer says) 61.2 mpg between filling up, my daily driving doing 60 miles a day on A and B roads in cumbria, I'm putting in 50 pounds a week but I'm wondering if I could get more mpg for my money. I don't know much about cars other than what I get told, I've been told about tuning boxes to give me more power and torque and mpg. The power out put is brill as standard but just wondered if I could get more mpg? Big thing is I don't know what the difference and damage between this boxes and " remaps " could anyone who's experienced one let me know as I'm looking at getting one. Thanks

[Johndouglas]

I've been told about tuning boxes to give me more power and torque and mpg.

If you're putting in 50 quid a week, that's giving you about 8 gallons to play with. If you do 60 miles a day for (what?) 6 days a week, that's 360 miles per week. That works out at around 45 mpg. A more reliable method would be to brim the tank, note the mileometer reading, run it till almost empty, then brim it again. Then do the sums.

 

Regarding the box fitting or remap. For any practical improvement in fuel consumption, it would take years to recoup the outlay for either of the two systems. In the past I've used both, a tuning box and a remap - mainly to improve my car's towing performance. Both systems were helpful but the remap showed the best improvement. Running without my caravan on tow, fuel consumption hardly changed.  

 

It's worth mentioning the fact that sometime in the future, when your car goes for MOT, the output of the engine will be compared with a DVLA database. It might be that any remapping would show, bringing about a failure.   Also were you not to tell your insurers about the fitting, your insurance would be invalid.

[paul.h]

The official fuel consumption for the manual 1.6 hdi 92 bhp in the handbook is given as 49.6 / 76.3 / 64.2 mpg urban / extra urban / combined. So depending on the accuracy of the numbers given in the first post and any later checks from filling the tank, at best you are going to get around 64 mpg in warm weather and less in winter. To reset the car trip computer, press and hold the button on the end of the wiper stalk. The roads in Cumbria are also not the best for good fuel economy - lots of hills, bends, narrow roads, queues through the towns and also possible need to overtake wagons doing their national speed limit of 40 mph. Often better fuel economy can be achieved by modifying driving style - leaving more room in front so no need to use the brakes often, not accelerating quickly, using as high a gear as possible, keeping the speed down. You could try different driving styles to see if your economy changes.

 

Something to be aware of, the 1.6 hdi can be prone to early turbo failure so do not skimp on oil and filter changes. Check your maintenance book but I think your interval may be 12500 miles, so at your 60 miles a day that will be at least 2 oil/filter changes a year. Use the oil recommended in the maintenance book. I may also have read that an oil flush should be done. If there are any early signs of turbo failure such as a lot of smoke, then it may be best to sort it rather than risk bits of metal going in to the engine.

[citroen_c3_hdi]

Thanks for the replies, I'm taking the car back for repairs due to the handbrake being stuck on a little bit and the tracking is off the the right, I've just put 20 pounds in which was 15 litres and it's done 160 miles and still going ... The car has got a tow bar and I think the fear box is wrecked as it won't go into 4 th or reverse gear properly, the car has 65,000 on the clock with full service history, the engine is emaculate condition not a speck of rust, there's no smoke at all not even when it's starting up, it pulls like a train without going above 2000 rpm at all times. I've been looking on line for research and it says if I got an induction kit I would get even more mpg. Why if I'm getting 45 mpg on average does it say I'm getting no less than 60 mpg on average, but why the big gap? Just to add there's an orange symbol on the speedo clock behind the steering wheel, it looks like an engine management light but I don't know what it means?

[paul.h]

The orange engine management light is supposed to be an engine shape and if this is on all the time it means there is a fault with the engine control/emissions systems. It needs the fault codes read to see what is wrong so it can be fixed. Until it is fixed the car may be running in limp mode which will limit the rpm and engine performance. Certainly do not do anything to the engine systems such as tuning boxes or induction kits until this is sorted since it will complicate fault diagnosis and repairs and if there is a warranty with the car it may invalidate it.

 

The gearchange cables can not be adjusted so possibly there is some wear in them or elsewhere.

 

The 45 mpg mentioned above is just a best guess without knowing the actual miles you are doing for your £50 since you have not said, nor the cost per litre for diesel you are paying which could be about 5p a litre more than elsewhere. It could be you are achieving the 61 mpg but to do a thorough check you need to fill the fuel tank to the top, note the mileage, drive around for a few days and then fill up to the top again and note the mileage and amount of diesel put in. At the same time reset the trip computer when you first fill up and see what mpg that shows over the few days to see if they are the same.

 

The fuel gauge can be misleading, being 6  orange bars. Each bar I think is about 7½ litres but a bar will not go off until the 7½ litres it shows has been used - so in reality a bar represents 0 to 7½ litres. So if you are getting about 13 miles a litre (61 mpg) then a bar can give about 100 miles.

[citroen_c3_hdi]

The orange light just comes on when the engine starts but goes off after a long (too long) period of time, I'm doing 50 a day on weekends I'm doing easily 65 miles a day, cost of diesel is 133.9 and I'm getting 75 miles to a bar of fuel when I put exactly 21 pounds in which gives me 15 litres exact which is exact half a tank and last me 180 miles before I need to stick another 21 pounds in. My hand brake is stuck on a bit and the tracking is off so once that's fixed I'm hoping for more mpg, when I do the 50 miles a day that's a combination of A roads a595 and B roads and town driving but no hold up other than traffic lights. Is there anything that could improve this mpg?

[Johndouglas]

If the handbrake is partly on and the tracking a bit out, then both these things could aid poor fuel consumption. The fact that the engine management light doesn't go off immediately needs investigating. The one thing that will improve mpg is to lower your driving speed by 5mph.

[citroen_c3_hdi]

I don't go over 55 on 60 speed limit roads, my cars going in to get fixed tomorrow on warranty there's loads wrong with it I only bought the car purely for mpg and I don't even get that even though the garage promised 3 of my family members it would do 15 pounds a week on the miles I do ... I know that's the biggest load of rubbish I've ever heard but I just humoured them but now there surprised that I'm taking it back but I'm just depending on getting my money back and getting a pug 1.4 HDI.

[paul.h]

Doing the calcs on the above:

1. 50 miles a day plus 65 miles a day at weekends gives 380 miles a week. Using £50 of diesel a week at 133.9p a litre is 37.3 litres = 8.21 gallons (1 gallon is 4.54 litres). Hence 380 / 8.21 = 46.2 mpg.

2. 75 miles to a bar of fuel on the gauge which is about 7.5 litres, gives 45 mpg.

3. 180 miles from 15 litres is 54.6 mpg.

4. The salesman said 380 miles a week for £15 (11.2 litres) requires 154 mpg - I do not think such a car exists !

5. The fuel tank is 45 litres so if you are filling it half full so just under 4 bars on the gauge are lit up, then to running out may give about 220 miles at 45 mpg or about 300 miles at 61 mpg.

I think the only way you will get the accurate mpg being achieved will be to fill the tank and note the mileage on the speedometer as mentioned above. The trip computer average mpg is since it was last reset, there may also be the current mpg which jumps about a lot and the miles of diesel left at the current mpg, which will also jump about a bit. Until the tank is filled, if you reset the trip computer so the previous owner's driving is not included, this may give you a better idea than putting in a few pounds in the tank and I have found that the trip computers on our cars have not been too far out. However, the different cars have shown different distances for the same trips with the 2003 C3 showing a few percent more than the C4 and C5.

[citroen_c3_hdi]

I took it back today and found the 4th injector (nearest the passenger side) is leaking cos it's black and thick black tar like substance around it plus when driving it there's a strong burning smell, how do I get more mpg I'm already doing 55 mpg at the most and avoiding sharp braking and sharp acceleration and keeping it in the correct gear?

[Johndouglas]

If the 4th injector is leaking, that's not going to help for your fuel consumption. Probably why your EML is staying on.

[paul.h]

Once the problems are fixed your car should perform better, so maybe wait until then to see what mpg it can achieve since it should improve. You could also see if the air filter is clean. Premium fuels may help improve mpg but the extra cost may not pay for any improvement.

 

What car did you have before the C3 and what mpg did that give ?

[citroen_c3_hdi]

I had a ford focus 52 plate 1.8 petrol zetec, that was getting doing all the same mileage 34 mpg but I was putting in 100 pounds a week in it had 135,000 on the clock. If I was to get my money back for more reasons than that whaf would be the best car for mpg not power?

[paul.h]

A look at Parkers.co.uk car reviews suggests your old car should give about 37 mpg, so with your driving conditions which gave 34 mpg, you are likely to get about 10% worse fuel economy than predicted for any car you consider. This suggests your C3 combined official figure would drop from 64 to 58 mpg. In the following it gives a Citroen C1 1.4 hdi may give 67 mpg but reducing this by 10% drops it to 61 mpg - but would you want such a tiny car ?

 

A google search came up with http://www.buyacar.co.uk/car_news/buying_a_car/archive_buying_a_car/article_best_for_fuel_economy_top_20_2527.jhtml

 

As well as mpg though, I would include other costs such as a diesel costs more than a petrol to buy but should have a higher resale value, car tax differences, maybe insurance cost differences, an old diesel may have higher maintenance costs than a petrol due to the exhaust particulate filter (dpf or fap), possibly more frequent oil/filter changes, fuel filter changes and if the diesel pump or the turbo fails any fuel savings are wiped out. With your high annual mileage of about 19000 miles, a diesel should cost less overall than a petrol provided it does not have any problems. If you do the costs on about 10000 miles though, a petrol and diesel cost about the same for the same model car if both are kept for about 3 to 5 years - any less and the petrol is cheaper. You also need to consider what size of car you need.

[citroen_c3_hdi]

That makes more sense, the ford ended up getting scrapped (p/x that wasn't worth anything) so they gave me a couple hundred quid for it, thing is people (family) often say to me 'it's just the way you drive' that makes your fuel go but my mrs when she's in with me says in driving fine, below the speed limit and avoid all sharp braking and acellaration. The only other car I've had that was brilliant on diesel was a Y reg rover 25 spirit 2.0 IDT 100 bhp that was getting easily 60 mpg around the roads that I drive in Cumbria on a daily basis which is why I went for another diesel because the rover ended up being scrapped after the turbo blew and decided to take the majority of the oil from the engine and whizz it round the turbo then half back into the engine then the other half out the exhaust and I was left with a car that had a destroyed turbo, destroyed injector and leaky, bent conrod, and the head gasket blew in one of the cylinders, but it was economical going from Cumbria to Glasgow on 15 pound of diesel doing 70 mph all the way before the turbo blew, me and my mrs very impressed hence why we got this car. I'm just seeing if there's anything more fuel efficient that's a 5 door diesel. But I'm going to see what the changes are with car when it's fixed.