Fuel economy

[WiNgNuTz]

Its dawned on me that i dont seem to be getting as many miles to a tank as some of you other derv drivers (usually between 5-600 on a full tank, cba to work out the mpg), so wondered if there would be any tips, other than a lighter right foot, for making my fuel go further?

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This tank im using now seems to be the worst so far, used just over half a tank, got 240 miles so far.

[Anton]

Your on a Lucas, not as efficient as a Bosch. You have a smokey tune, if you want more economy either burn clean or turn your boost up.

When was it last serviced? Fuel filter too?

[WiNgNuTz]

Hmm...had a service not long ago, but the fuel filter was missed, and i havent got round to doing it yet....should do that really. As for the tune, good point. Might back the fuel off a bit more, its not as smokey as it was, but there is still room for adjustment.

Would the fuel filter really make much of a difference to economy? I cant say im that fussed about it, its still a million miles better than my old 1.4! A tank lasts me 2 weeks or so now, as opposed to just over a week in the 1.4.

[Anton]

I run veg but the changing the fuel filter is like gaining 5bhp.

Honestly I think it makes a huge difference, get it changed. I service mine every 5000 miles, fuel filter maybe every 1-2000 miles.

[WiNgNuTz]

Hmm...every days a school day, eh? I'll get on that tomorrow then! Can turn the max fuel down too at the same time!

[Anton]

I'd turn the boost up, 18psi is hardly pushing it mate.

[4WayDiablo]

I'm about the same 5-600 on a tank usually around 530-550 all depends on my driving style thoigh

[WiNgNuTz]

Might do a bit of both tbh, maybe another turn or 2 on the wastegate, and turn the fuel screw back a little.

[cpikey316_]

Fuel filter is really easy to do, and fairly clean too. On my old DT I used to do it every 4k miles. (and that was an untuned one running on *shock* diesel!

[Popeye_6]

fuel filter can make a big difference to economy if its all gacked up.

also might be worth having a look at your leak off pipes. there could be a small seep

[WiNgNuTz]

fuel filter can make a big difference to economy if its all gacked up.

also might be worth having a look at your leak off pipes. there could be a small seep

You'll have to excuse my ignorance, as im still fairly new to the whole diesel/tuning/mechanics thing (but i like to think im getting there! ), where would i find the leak off pipes?

[cwspellowe]

The small hoses linking the injectors together, about 10cm long and rubbery.

You'll have one between 1&2, 2&3, 3&4 and a blanking cap on number 1 (from the flywheel end) and a fuel return hose from number 4. They can perish with age, get some braided fuel related stuff from eBay and replace, £5 and a couple of minutes' work, tops. In fact just replace them anyway for the effort and cost involved.

In fact in fact, if you have the top mount intercooler you'll need to remove that to see them. Forget about the TMIC when i've never driven a DT with one on

[WiNgNuTz]

yeah still got the TMIC, no doubt itll end up with a FM, but not any time soon, need moar monies for those kind of shenanigans! Will get on the leak off pipes though, im pretty much learning as i go along. Love a challenge! Take it apart is fairly easy, remembering how i took it apart, then reversing the procedure to put it back together is the fun bit!

[burnmw]

Sounds about right to me, however might be worth lifting each corner of the car and testing that none of your brakes are catching, that can bring down your fuel economy.

[WiNgNuTz]

Sounds about right to me, however might be worth lifting each corner of the car and testing that none of your brakes are catching, that can bring down your fuel economy.

Just realised i havent tried this, will do so when i next have the car on the jack/stands.

Anyway, figured i'd add to this thread as opposed to starting a new one, as the new query is kinda related.
Basically, since starting this thread, im being less "spirited" with my driving, which means less of the full throttle. When the revs are low, thus off-boost, the smoke that billows from the exhaust is something to behold! Also seems to hesitate for a moment before bringing on the power. Could this be overfuelling? I know the Lucas pumps are renowned for being smokey when tuned, but this is ridiculous!

I'm pretty sure the boost is being controlled by the fuel screw, as i gave the wastegate a good couple of turns the other day, and only made it up to about 19.5psi on the gauge, so if i turned the fuel down to combat epic smokness, would that possibly then reduce my BOOOOOOOOOST? And before you ask, its clean ON boost, just resembles a locomotive OFF boost. Boost compensator (if you can really call it that!) is wound almost all the way in.

Any thoughts guys/gals? I think ive covered everything.

[Jarrus]

Hmm...

I have a similar problem on my 205 1.8 DT but thats completely standard so it can't be over fueling(it runs really clean...) thats the issue I don't think it could be sticky injectors either because my expiriance has taught me that injectors either work or they don't.... (weather they work well or not is a different matter....) maybe fuel filter is causing the problem because I haven't changed mine since I bought the car... so it is on the list come service time, probably do it sometime soon... any other ideas? Injector leak back? only does it some times... you put your foot on the go juice and it like jumps a bit then goes...

... as for fuel economy I used to get about 45 mpg on average from my 306 when it had the 1.9 in it(tuned lucas and K14 running 18 psi with little smoke when flooring it)..... I used to drive to telford and back 5 days a week on the m54 and on the a5, and it used to get the hammer down for that.....my new job where I only drive 5 miles there and 5 miles back then I got about 38 mpg

I'd say really that the people quoting 600 miles a tank either granny there cars or do a lot of dual carrage way or motorway driving.... The most I ever got out of a tank was 650 miles and that was doing 90mph on the m6 from cannock to solihull (70mph on the m42 tbh)