Zafira Diesel Fuel Consumption

I picked up a new 2.0TDi Zafira last Wednesday and over the weekend did a 500 mile mostly motorway trip at around 70ish. Ichecked the fuel consumption and was disappointed that it was 42mpg whereas from the manual I was expecting high 40 / low 50s.

My question is does the fule consumption get better on diesels as they run in ? The guy who delivered the car mentioned that the engine would 'loosen up' after 300 miles but I'm not too sure what that means !

Thanks in advance

Lou

Reply to
Lou
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It means "Don't go over any bumps because it will fall out"

--Nick.

Reply to
Nick

First off, diesel engines are not properly run in until you've at least

50,000 miles on them. Once run in, they're quieter, smoother, perform better and use less fuel. My Mondeo TD was using less fuel (and no oil) at 100K then when new, heh.

Second, don't, do not, never, etc. treat this new engine with kit gloves, or forever will it be using oil!

Third, you may also need to get used to the way it drives - there's an article on my website (well, one or two) regarding fuel consumption. If you're new to turbodiesels, there's a definite knack to getting the most from it in both terms of fuel consumption and performance, and if you've come from something petrol, multivalve, with totally different power delivery characteristics, there's quite a difference! :o)

Reply to
DervMan

Seconded, was told by a trustworthy Vx Mechanic to "wring the arse off it, you wont do any damage, just keep a very close check on oil consumption"

Got an astra with exactly the same engine in, we picked it up with less than

5k on the clock, it used oil heavily to begin with but soon settled down, has about 15-16k on the clock now and uses no oil..
Reply to
Mark Craft

Please define "run in". And lets have the evidence. Do you really believe they get quieter ? Why ? Smoother ? Less vibration ? How does that work ?

I assume you are only talking about ring/piston/bore wear - do you make the same claim for petrol engines ? If not, why not ? Do they use different materials for bores, rings and pistons on diesels ?

I've heard these claims before but I'm not sure they are ever based on any engineering facts.

Hugh Jampton

Reply to
sro

Like a pair of shoes, I'd suppose. Not new, but rather better than they were when first taken out of the box.

Given that I made the above statement, yes!

Have you listened to brand new diesel engines, then? Then have you listened to one when it's a few thousand miles old? Then twenty thousand miles old? And every few thousand inbetween?

We had a lot of diesels on the fleet I used to work with, and what would typically happen is that I'd only ever get to drive them every few weeks, or in some cases, a few months. The car with the most obvious difference is the MB E220 CDI automatic we had. New, it was somewhat rough, and a big disappointment. After 8,000 miles, it was a bit better, and after 30,000 miles, it was far, far better.

Fuel consumption? Monthly averages of 41 mpg new, 43 mpg at 8,000 miles, 44 mpg at 30,000 miles (the driver did ~30K a year, collected the vehicle in spring, so we can discount the 8K fuel consumption on account of it being a different time of year if you want to be fussy).

At 108K, when we traded in the Mondeo TD I ran, the engine was quieter and smoother than it had ever been. Perhaps it enjoyed my ownership, I don't know! It was also using quite a bit less fuel, too.

Search me. I can only go by how they feel when driven. I don't have any scientific evidence.

I don't know. To be honest, I don't particularily need to know, either.

Unfortunately, I don't have the resources to go out and buy two brand new car, keep one in the box, then after a couple of years, test them back to back.

But I can assure you that over a period of time, I've been able to extract better fuel consumption from _all_ of my vehicles under like-for-like conditions. You can see the effects of this on my website with the various charts - but of course my driving changed during some aspects (most notably my time with the Cinquecento, since for the second half of ownership she was primarily city-bound). You can also see the seasons coming and going, too.

I'd speculate that a little bit of engine wear is a good thing, but too much and of course this is a bad thing, heh.

Reply to
DervMan

I had the same problem with my Vectra, with basically the same engine (2l intercooled TD Ecotec). Up to about 20,000 heavy oil use and 42 mpg. 20-40k less oil and 45 mpg. Now 50k+ and uses virtually no oil and 50+ mpg. My last brim-to-brim was 54 mpg with gentle motorway (60-65 mph) and town (not big city) use. You may not get as much because of larger front area of Zafira and more drag.

Alec

Reply to
Alec

I recommend people to not measure fuel consumption until the car has done

1,000 miles and to not expect full economy on a diesel for 5,000 - 10,000 miles.

Driving it harder early on will loosen it up quicker too!

A word of warning on oil consumption too. It could drink oil early on so check it regularly. This could also take 5,000 - 10,000 (or more) to settle in.

Your car will probably not reach its peak for 20,000 miles or more!

Reply to
Alan

I can tell you it's tru for a diesel engine.. i recently had the engine in my iveco turbodaily van re-conditioned, it's a 2.8 litre, 4 pot direct injection TD engine, when i got it back from the re-conditioners it was shaking about like mad on idle, the gear box vibrated when driving, she used a litre of oil every few hundered miles and i got about 20 mpg on a run to southampton from the midlands,

got just over 1500 miles on her now, and she's a lot smoother at idle (the cab of my van is mounted on rubber mounts, so it used to chake that) , the vibrating's gone while driving, she is deffinately a bit quieter (most new engines you can hear the injectors operating.. a metalic pinging noise, that goes after a little bit of carbon builds up) i'm using no oil at all now.. which is a first for any van engine i've ever owned, and i'm getting around 24mpg.. it'll take a while to get fully run in, but i did what the engineers told me when i first ran her.. drive her like you intend to drive her for ever.. i.e stay off the red line but never ever ever drive softly with a new diesel engine, or the bores will glaze and you'll be for ever putting oil in,

i know that's true as it happened to my last van's engine, i run that in like you used to.. not going over 2000 rpm, and keeping below 50mph.. used oil all it's life.

A diesel engine is built a lot stronger than a petrol, so they prolly do use different materials for the rings and bores, a petrol engine has a compression ratio of about 8:1, diesels are around 20:1, with pressures of a few hundered psi on the compression stroke,

But i think one of the main things.. diesel fuel is a lubricant.. i.e. an oil, petrol is a solvent, one of the reasons diesels last so long is they are always lubricated at both ends i rekon,

And it's deffinately true diesels like to be worked hard, don't lug them in the wrong gear, but just work them, you can't over rev a diesel unless you down shift inadvertnantly, and full revs are usually about 5000 rpm max, it all seems to help make em last longer, but they do need treating differnetly to a petrol engine.

Reply to
CampinGazz

Sounds like they didn't bother honing the bores leaving the engine to do it over a few thousand miles. Not correct procedure, though, as correct honing gives a longer life.

Reply to
Dave Plowman

50k is a little exaggerated imho! All engines take time to bed in when keeping the load light is more important than keeping the revs down.

There is a lot of nonsense talked about diesel longevity that is still based on old deisel that had very low specific outputs and ran almost constantly. My local bus company has two old wagons that have over a million miles on their engines, the modern ones don't last anything like as long.

Camgear and transaxles and various other expensive bits don't know what is fuelling the engine and yet there is this belief that they go on forever because there brother in laws sisters boyfriend has a Sierra TD with over

300k on it etc etc

Quite why these engines tend to use oil is unknown, but thrashing the goolies off a new engine, diesel or otherwise, is not good news. Do not let it labour and use the revs, but thrashing especially from cold is best avoided! ;-)

JH

Reply to
JH

Just because a Merc motor does this you can't really extrapolate it to all diesels, imho. If you go and fit reconditioned injectors they tend to be noisier than used ones, doesn't mean that they are somehow worse performing tho...

The chap i used to chat to a lot said that combustion noise (as opposed to other mechnical noise) tended to decrease as the engine aged, though whehter this was due to coke build up or wear he didn't know. Less noise doesn't necessarily mean good news though.

If it was "looser" then it would do all those things.

In all fairness bore wear tends to be less on diesels because the increased fuelling needed to start a deisel isn't so damaging to the bore oil film. You need to take into account though that a 2litre diesel used to only be good for 60-70bhp, now we're looking 150bhp, those rings are getting a much harder life than they used to!

Indeedy. I've seen a number of tests with engines where you thrash the bananas off a new engines, initially it gives substantially more power than the carefully run in engine, but then it tends to shag out early...

Cheers,

JH

Reply to
JH

It's a decent ball pack figure, though - by this mileage, lets say over four years, the donk is nicely run in but the rest of the car is just starting to age a little bit.

Yes, indeed, but you're talking about the initial process as used on older donks.

constantly.

I don't think it is nonsense, I think it's more accurate to say that modern petrol engines should a similar amount to modern diesel engines. :)

I think this is an exaggeration; but there's a certain view regarding how these vehicles are used. If somebody does a moderately high mileage - lets say the annual mileage is 36K - on a Mondeo-sized car that's approaching ten years old. It probably sees the inside of a service bay three times a year and will spend a large chunk of time with the engine at temperature, probably at a light load because it's cruising.

Compare this with the owner who lives one side of a city, and works on the others, and does 6,000 miles a year. A higher proportion of these miles will be with a cold engine, and under a varying load - and it'll see a dealership once a year.

Over ten years, one will cover 100,000 miles, one will cover 360,000 miles, which one will have a more worn out engine?

These direct injection Vauxhall diesels are renouned for using oil if they're treated with kid gloves from new - but I didn't write thrash, just use them normally. Not unlike the 2.0 Perkins-derived diesel as used in the Maestro and Montego (and probably the same for the current variant of the engine as used in the various Rover / MG products).

Oh indeed, when cold the engine deserves a lot of respect!

Reply to
DervMan

Aie, the Merc had the biggest difference between new and used. The 406, Laguna, Mondeo and Vectra were similar, but less so - these were all the older indirect injection donks (yeah, one of the original 1.7tds Vectras, heh!) rather than the newer direct injection donks.

That would figure, I suppose. Different engines do different things - the Endura-E tends to get a much noisier idle with age (the tappets, heh), but quieter on the move. Some people tell me that theirs suddenly got noisy at around the 30,000 mile point, which just happened to be after the first major service (when the spark plugs are changed). Well . . . I've not noticed it myself, yet.

Spot on.

Yes, you're right, but of course it does depend on how it's driven. Presumably at a motorway cruise, a modern engine will only be using what power it needs - it's only under a heavy load that the donk has to cope with the increased output. Plus I'd hope that modern engines have better quality materials, or a better design, to cope with the additional stress.

Is torque of more concern? The Mercedes Benz 190D 2.0 produced 75 PS and

126 Nm, whereas the current BMW 2.0 diesel produces twice the power, 150 PS, and "shed loads" more torque, at 330 Nm.

That's interesting! I'm not advocating that a brand new engine is thrashed - although my Ford dealership tell me that new cars are already run in at the factory (to which I said, "so they're not really new, then?"), and "can be driven like a racing car if you wanted to."

Reply to
DervMan

Strange isn't it? Curiously my ZX seems to smoke less than when i first had it some 30k ago, but i put that down to it being used "eagerly" once in a while, whilst it used to be stuck in London. ;-) More worrying is the sline whine from the 'box. Third started at about 50k, now fifth is quietly saying hello at 80 odd k.

Weird. I had enough Valencia engined cars to recognise that they were quite happy and sounded very sweet if they'd been used for longer journeys. Short journeys turned them so horrid they really did sounds like the oil had been drained out. Mine had often done 70-80k hard miles (but warmed through and

3k oil changes) and sounded very sweet.

Very true, all else being equal it's better to use an engine with lots in reserve.

Wow, let's hope the gearboxes have been redesigned in that time! ;-)

I'm sure that's more down to the that people probably keep asking "how do i run it in". Does it still suggest you do so in new car owner manuals as a matter of interest?

Cheers,

Jon.

Reply to
JH

Zafira - Cd .33, CdA .78 Vectra Cd .28 CdA .61

Vectra is really much more slippery than the Zaf! Didn't expect that...

Reply to
Tim S Kemp

There is one thing though that everybody has missed.

Regardless of whether you thrash the living daylights out of the engine or not, remember that you have a turbo charger and these things do require a little respect.

First of all, take it steady when you first start the engine and set off to give things a chance to warm up and likewise do not just switch off the engine seconds after you have finished thrashing the thing. Try and take things nice and steady for the last couple of miles of your journey.

After all, whilst the main engine might be happy being thrashed for 200,000 miles, I have seen mistreated turbos die in less than 30,000 miles and they do not come cheap.

Reply to
Networkguy

Mpg does seem alittle low for this, but yes it will loosen up. However not in 300 miles! 3000 maybe, more like 5000 before its fully loosened up. Anyway, with these engines, and indeed all new Petrol or diesel, especially diesel, it needs to be driven fairly hard from the word go. Do not run it in gently else you'll end up with massive oil consumption, which has been in these groups several times with the 16v DTi engines. For the first 500 miles I wouldnt run it to the governor every time, but it needs driving hard- but without labouring. Use the gears aplenty and make sure you see 3500-4000rpm under plenty of load at least once a day.

Tim..

Reply to
Tim..

Out of interest, how much did it cost to get it re-conditioned? I might run my Fiesta up to 300k, then get it re-con'd, then give it another 300k worth of use.

I could also treat it to a new shell at 20 years old when it's seriously rusted away, and then it'll be like Trigger's broom in Only Fools and Horses (20 new heads,10 new handles, but the same broom).

Peter

Reply to
AstraVanMan

Guys

Thanks for all your advice - I'll let you know how I get on.

Cheers

Lou

Reply to
Lou

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