2.2Hdi fuel consumption

[PeterN]

This is not strictly Peugeot but it is related. My 2.0L Hdi 406 does about 60 mpg at a steady 60 mph and averages about 55 mpg, I now also have a a 2.2 Hdi C5 which barely manages 50 mpg under the same conditions and averages only about 45 mpg driven in the same manner over the same routes which seems to me very poor, people who are running 2.0L C5s seem to be getting similar mpg to my 406. Is there something wrong with it or is it just a poor engine? Anything I can do to improve it?

Thanks

Peter

[Doggy]

A 2.2 will generally use more fuel than a 2.0, for several reasons.

In 406's, all 2.2's have diesel particle filters, (& I believe the same is true of C5's)?
This is bad news, because you have a heavier exhaust system, plus the additive tank and associated plumbing and electrics. When regenerating the filter, the system dumps fuel into the exhaust to start a fire to burn the soot off. Added to this it switches on every electrical gadget it can to load the engine up to produce more heat, and bypasses the intercooler to increase the charge temperture to prevent it cooling the exhaust.

Other considerations, the 2.2 generates more torque, so has to have a bigger dual mass flywheel and clutch. The 16 valve, twin cam cylinder head is heavier, the reinforced sump with its balancer shafts will add weight too. The induction system is more complex, the egr system is water cooled, in short, it's a lot more sophistcated, all of which adds weight.

If you de-FAP it, (get rid of the DPF), you stop fuel being wasted in regens, but you don't get rid of much of the weight.

All this sounds pretty neagtive, but you have to consider the advantages. The 2.2 is quicker, quieter, smoother and still returns respectable economy. I wouldn't swap mine for a 2.0

It's a case of horses for courses. If you want maximum economy & cheapest road tax, get a 110, for comfort & speed get a 2.2

[PeterN]

Thanks for that. I had thought that perhaps the balancer shaft system sapped some power as the 2.1XM is more economical than the 2.5 which has them also the extra weight and power will have some effect, but I don't use or need the power so I would have been happier with a 2.0L, but as I anly paid £300.00 for this one I thought I ought to give it a go, its certainly very smooth an torquey.

Regarding the FAP system, all the later cars have them but the fuel consumption seems to be very much better, the 2.0 16v giving about the same power as my 2.2 but with consumption on a par with my 406.

Has anyone fitted a tuning box to a 2.2 and noticed any fuel consumption improvement, I know that a remap is the proper way to go but that would cost me more than I paid for the car.

Peter

[Doggy]

Don't know on the tuning box, (there's a remapped file or two going about for 406's, that unfortunatley won't work on C5's).

If yours has the FAP, it can be removed very cheaply if you're interested.

[OdinEidolon]

45 mpg is fine for the 2.2, if you do not drive very carefully. I do drive very carefully and I do 70% motorway at 70mph and my fuel consumption is as in my signature

[Doggy]

Having a remap and lead boots, my fuel consumption is every bit as noteworthy as Adriano's, but unfortunately for all the wrong reasons.

About 42/43 mpg - If I behave myself.

[OdinEidolon]

Having a remap and lead boots, my fuel consumption is every bit as noteworthy as Adriano's, but unfortunately for all the wrong reasons.

About 42/43 mpg - If I behave myself.

Well I'll remove the FAP soon and remap the car, I'll hope I'll break the 55mpg barrier

[PeterN]

I normally drive with a glass slipper, that has given me an average of 55.4 mpg over the last 6,000 or so miles according to the readout on the 406, so low to mid 40s from the 2.2 seems very poor to me, it seems that some others are doing better so I think something must be amiss with it. Thanks all for your input.

Peter

[Doggy]

If you want a de-fapped version of your ecu file, let me know.

[PeterN]

OK thanks for the offer.

Peter

[swarf]

mine averaged 38.2 mpg over about 3000 miles at an average speed of 22mph, which is mostly town driving, at a steady 60mph unloaded I get about 48mpg, more would be good but compared to my old petrol mondeo i'm happy with this, before I had the remap and defap I was only getting 1mpg better.

[OdinEidolon]

Yesterday coming back from the injector place which cleaned and calibrated my injectors I got 65.7mpg (4.3L/100km). This is a motorway trip at a steady 70mph, 150km (~90 miles), with some tricks to keep the consumption down.

[Editor]

what they all said. We went from a 2.0HDI 110 to a 2.2 136BHP. I never understood where those extra 26 horses were & the economy was over 50mpg in the 110 & just over 40 ish in the 2.2. Then I bought a Van Aaken tuning box off ebay (prolly the best there is) & whallop. Safe overtakes & plenty of power-WTF it never came from the factory like that I'll never know-it would have been an instant hit. I've known about FAP, eolsys & pollution issues since 2002-that's me on the HJ site talking with screwloosed about it all over a decade ago-might have been dieseldawg on there.

Much later down the line & due to the enormous efforts of your sister forum, the coupe boys, there is some very good news on this 2.2 unit. For not that much effort but you need to be systematic & work through the hoses/electrovalves/swirl issues & then start removing what isn't needed in the EGR system, replacing the cat & finally the FAP filter with straight through prior to a defap remap you'll end up with a now reliable unit that is returning over 50mpg but outputting close to 200BHP. I had the remap on my still fapped 2.2 last year & it's nice although no change in the economy. The bang for your buck moment is when that blasted FAP is deleted out-pull, pull, pull, hits 3k revs & apparently your head get whipped back as it launches.

More salutory is that I dearly wish I'd defapped mine at the same time as the map. Or just defapped it running standard 136 (there is a map for that as well). It removes 90% of the issues with this unit & IMO that's vastly higher priority than hunting for power gains.

It's possible that I might have my Van Aaken box for sale-I want to investigate exactly what the internal jumpers in it actually do & also try it on my new 110 as well. I have to say that it compared very well to the remap-probably stronger pull when you need it for overtake but quite so strong for as far going right up the rev range. The 180 remap is actually quite civilised & grown up-the Van Aaken seems more sporty/agressive. Anyhow-I ran it with one on for about 50k miles.

But defap & make sure ALL the hoses are known good 1st, electrovalves are doing what they should be & esp that swirl system thing. I so wish I had.

[OdinEidolon]

Sorry to tell you but a tuning box is just never, never, never going to match a remap, even a bad one, in terms of performance, economy, reliability. You just feed your ECU with false readings.

Also I've driven 110s and my 136 and I certainly can see where the additional 26 horses lay. I do not know why you did not feel so!

[Editor]

Sorry to tell you but a tuning box is just never, never, never going to match a remap, even a bad one, in terms of performance, economy, reliability. You just feed your ECU with false readings.

Also I've driven 110s and my 136 and I certainly can see where the additional 26 horses lay. I do not know why you did not feel so!

oh hello there! Never meant to convey that it would-I have a feeling we've had this conversation before. It's possible that my 2.2 might have always had a residual issue-possibly swirl valve actuator rod tip broken. And memory over this length of time can be odd, but I must say I found the 2.2 as standard a disappointment. Just saying that it was the effect of the VA smartbox, regardless of how it did it, that revealed to me what the 2.2 could have been & I had that long, long before the forum remapping projects were around. Pre defap knowledge days in fact. So I feel quite fondly disposed to it! But yeah-do it once, do it properly. Which will shortly take me into enquiring about forum maps for the 110..

BTW I have a 140k good 2.2 engine up for grabs-blew the turbo oil seal last month because like an idiot I never got round to defapping it & I think a hose failed big time on it as well. Any use?