1.9D economy on cold runs......

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MULLEY
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Re: 1.9D economy on cold runs......

Post by MULLEY »

DavidRutherford wrote:Hmm..

I get the feeling your dyno session is lulling you into a false sense of security about the engine.

My money would be on slightly retarted injection timing. If the timing is even just a fraction late on an XUD, power output is not really affected, but the economy will be quite badly down. I had a TD with exactly this issue a good few years ago: damn thing would barely do 35mpg with all the tricks in the book. Checked the timing, and it was definitely a bit late. Advanced the timing slightly, and the power was identical but the economy jumped to 44mpg. What was most noticeable was there there was more diesel "clatter" at idle and when revved. Before the engine sounded very smooth, and afterwards it sounded somewhat "harder".

If your cambelt needs doing, that won't help either, as if the belt has stretched even just a teeny tiny bit, that will retard the timing.

New belt on, and check the timing. Requires a dial test indicator, and is a bit of a pain of a process, but well worth it.
Interesting thoughts, never even contemplated that a slightly stretched cambelt would affect anything, i just presumed that as they get older they would stretch if really old & well overdue, but otherwise were always a bit tight & then settled down to their operating length?
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Kitch
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Re: 1.9D economy on cold runs......

Post by Kitch »

Truth be told the thought of pump timing did enter my head (because it entered my head after the surprisingly good dyno performance). I wasn't sure what sort of an effect it could have on economy, and the economy was always up in the 40s (even 50s a couple of times) way back when it was last on the road.
It also runs very smoothly - less clatter than many XUDs I've heard, but put this down to the previous owners' 3000mile oil services.

I don't have any first-hand experience, but I'm not convinced by the 'belt stretching' notion too much. If the timing was that precise, you'd have proper stepped timing pins wouldn't you? And if a belt stretched to the point it affected the timing, surely you'd be on a one-way ticket to Bentvalvetown? Because if it stretched that much, surely it would run off the end of the tensioner pulley?

I removed the mags and the car does feel a little bit livelier. Not fast by any stretch, but it's improved slightly and I'm sure it's going to lead to smaller throttle inputs. I'm also considering changing my journey; I currently drive down a slow, tight, twisting country lane with a cold engine. Lots of braking and then accelerating going on. I could travel a mile extra and just stick to straight lanes on main roads, but I'l wait until after I've measured the economy this time.
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Re: 1.9D economy on cold runs......

Post by mat_fenwick »

A couple of years ago I looked at the effect of my route to work on economy - yes, I am that sad :oops: I've got a choice of one 30 mile hilly and twisty route, and a 50 mile straighter and (slightly) flatter route. Over a couple of tankfuls I stuck to one route, then the other; trying to keep my speed and driving style consistent from day to day. I can't remember the exact figures (which are irrelevant anyway as it's a different engine) but the difference was in the order of 25% :shock: Enough to mean that whichever route I took, the difference in actual fuel costs was similar to normal tank to tank variations.

I actually go the long way round more often now - it takes longer and costs slightly more in fuel, but I'm trying to get my tyres to last more than 10k miles...
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Tinkley
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Re: 1.9D economy on cold runs......

Post by Tinkley »

10k? More like 25-30k here in darkest Hants and the wonderful (6" potholed) Surrey bypasses! Mind you mine is a petrol....

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Re: 1.9D economy on cold runs......

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10K, you crack me up, i know that you've already gotten through your vredestein's that i recommended a few years ago, mine are still fitted to my car & even allowing for changing over to winter tyres for approx 6mths of the year every year, they are 6years old & must have covered at least 36k, but i do change the fronts to the back etc....They'll need replacing for next year though, so i've done pretty well. It must be that tuned up turbo & all that extra torque thats killing your tyres or the excess speed whilst you're enjoying yourself ;) I'd be crying if i had to replace tyres every year if i was only getting the mileage that you do. Aren't van tyres supposed to be rock hard?

Apologies for the thread hi-jack.
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Re: 1.9D economy on cold runs......

Post by mat_fenwick »

Just looking through my history and since I fitted the Vredesteins I've gone through another set of Firestones, Uniroyals and am coming up to 15k on my current Michelins. I do the front to rear swap, almost never spin the wheels and every now and again I even try to drive economically (got high 40s on the last two tankfuls 8) )

I'm heading for a guesstimated life of 30k on the van tyres, and I never drive that fast or hoon it round the bends. I wonder whether the fairly frequent full throttle overtaking of dawdling tourists is responsible for tyre life and fuel consumption???
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Re: 1.9D economy on cold runs......

Post by MULLEY »

What about late braking? or do you have to do a lot of braking because of the roads/route? Does the outer part of your tyre wear out 1st? If it does that means you are cornering hard, slow down is my advice if you want to make your tyres last.

If you are always putting plenty of torque through the tyres they will slip slightly without you realising, the tread will heat up & flex, this causes the very quick wear, again, if you're in a higher gear & less throttle will help. You hoon ;)
2002 C5 2.0 HDI Estate - Jasmine - Now SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - My daily
1991 Gti 16V - Blaze - crash damaged, will get repaired.
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN

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Re: 1.9D economy on cold runs......

Post by kiwi »

MULLEY wrote:What about late braking? or do you have to do a lot of braking because of the roads/route? Does the outer part of your tyre wear out 1st? If it does that means you are cornering hard, slow down is my advice if you want to make your tyres last.

If you are always putting plenty of torque through the tyres they will slip slightly without you realising, the tread will heat up & flex, this causes the very quick wear, again, if you're in a higher gear & less throttle will help. You hoon ;)
Can I say put Nitrogen in your Tyres =D> [-o< argue:-(

I rarely use my brakes (unlike the wife) and majority of driving done on 100kph roads only problem is lots of cornering and surprisingly since owning the diesel and miles per hours gauge chomping along at 60kph reads 91kph on the GPS which ultimately converts to 56/57 mph. The so called sweet spot of economy from the Govermint figures. Of course this drives the kiwis nuts following because 100kph is a target and anyone driving less than 110 kph is holding ost them up. Trucks/buses 90kph the limit not you would notice either. Trick here is finding the right type of tyre compound that does not get chewed up by the abrasive road surface designed for the colder part the island and heavier rainfalls. Well thats how I have to drive these days, more comfortable especially when nailing into a corner posted at 35kph :lol:
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Re: 1.9D economy on cold runs......

Post by Kitch »

kiwi wrote: Can I say put Nitrogen in your Tyres =D> [-o< argue:-(

No.
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Re: 1.9D economy on cold runs......

Post by mat_fenwick »

Kitch wrote:No.
:lol: :lol:

How about taping up all the door gaps? That might make all the difference! Downside is you'd have to have someone follow you in a separate car to tape up the driver's door again every time you get out, and their fuel costs may outweigh any savings made...
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Re: 1.9D economy on cold runs......

Post by MULLEY »

To save fuel you have to drive slower, accelerate slower & avoid the middle pedal as much as possible, whats the rush ;)
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1992 TZD Turbo - Bluebell - My daily
1991 Gti 16V - Blaze - crash damaged, will get repaired.
1990 Gti 8Valve SOLD - looks like it's been scrapped
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1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN

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Re: 1.9D economy on cold runs......

Post by Kitch »

MULLEY wrote:To save fuel you have to drive slower, accelerate slower & avoid the middle pedal as much as possible, whats the rush ;)
Life being too short and only giving you one go at it too?!

Anyway, I'm gonna top it again soon so we'll see what the economy is like then. Just got back from an extended trip in the estate. (6 miles each way) and I do enjoy the involvement needed to get it up to speed and keep it there. But it needs to be aiming for 45
mpg really, otherwise I could have a petrol for similar costs.
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Re: 1.9D economy on cold runs......

Post by MULLEY »

I think the n/a is quite fun to drive tbh, it can whizz along when required & i've done plenty of overtaking since getting used to driving it. It's not a quick car, but i still seem to out accelerate about 80% of most drivers upto 60mph without even ragging the car, they soon whizz by when they are doing 80, but i'm safe in the knowledge that i'm getting nearly 60mpg whilst they're getting naff all, they are either stupid or rich, or possibly both.
2002 C5 2.0 HDI Estate - Jasmine - Now SORN
2011 Mini Cooper D Clubman - SOLD
2016 Mercedes A180D Sport - Auto refinement
1992 TZD Turbo - Bluebell - My daily
1991 Gti 16V - Blaze - crash damaged, will get repaired.
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014
1988 CX 25 GTI Turbo2 - SORN
1996 - AX Memphis 1.5D - Dream - SORN

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Re: 1.9D economy on cold runs......

Post by Defender110 »

Yes I like the drive of a N/A too.
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Re: 1.9D economy on cold runs......

Post by Mothman »

mat_fenwick wrote:
Kitch wrote:No.
:lol: :lol:

How about taping up all the door gaps? That might make all the difference! Downside is you'd have to have someone follow you in a separate car to tape up the driver's door again every time you get out, and their fuel costs may outweigh any savings made...
Not neccessary to get someone to follow you to tape up the doors. You could do that yourself with the window wound down. You would get most of it anyway. Need to be slim and fit though!!

Andy