Upgrade to 170 BHP with big fuel savings ?

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fifth_cit
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Upgrade to 170 BHP with big fuel savings ?

Post by fifth_cit »

I was reading RichardW's post re "The Futures Diesel" and decided to check out the fuel consumption figures for the latest 170 BHP C5 Tourer.

The first thing that I noticed is the road tax bracket has reduced from £155 to £110 per year and the Consumption figures are :-

________________140 BHP___170 BHP___% Saving
Urban____________35.3_______41.5______17.5
Extra Urban_______56.5_______64.2______13.6
Combined_________46.3_______53.3______15.1

So 2 questions. How have they done that ? and what are the chances of getting mine upgraded ?

I have to take my car in for a safety recall on Wednesday and intend asking for a software upgrade. I know the answer will be no but it will be interesting to see their response.

I will of course keep you posted.

Keith
C5 III Tourer 2.0HDi SX
Previous Citroens:-
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Post by citroenxm »

More Power on a DERV engines does NOT always mean higher fuel consumption..certainly on these new "Electronic" engines

The 170bhp obviously has a better Power to weight ratio, meaning then the engine has to work LESS to move the body, meaning useing less fuel.

Paul
Sharing a pug 207 1.6 hdi Sw 16v.
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Chlorate
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Post by Chlorate »

Tis the way technology is heading nowadays, the EU has declared war on the internal combustion engine.

As Paul said, it's probably got a lot to do with power-to-weight, but it'll also be down to the engine design being much more efficient than older ones, and probably some interesting things going on with the fuel injection.

I had to do a project on diesel engine design a couple of months ago, and some of the new ones popping up are rather incredible WRT power, torque and exhaust emissions.

As for upgrading: if the new engines are the same size and with the same mounts etc as the old ones, can't see why you wouldn't be able to plug a new one in.
Would probably have to swap the running gear with it too, don't want to be breaking anything :lol:

-Alex
Citroen Xantia Exclusive HDi

previously:
Citroen ZX Volcane - RIP
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HDI
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Post by HDI »

Don't you just love the way the EU kicks the emissions and carbon footballs around, scoring own goals with electric alternatives !!

So, lets have a look at that electric alternative option.
Most European countries have an energy generation problem, that is struggling to meet demand. The UK is almost in crisis with this issue which is why the government panic ordered new French designed and built Nuke stations.
So, we all start driving electric vehicles around then, great idea, where is all the energy for recharging the batteries going to come from then ?!
Given that even a small car has 100 BHP, that is 75 KW !! OK not all the time but on a say 35 mile journey with an average power consumption of 30% of max, for the sake of discussion, and to recharge quickly say in 10 mins, it is going to need a charge rate of 135 KWH !!!!!! My calcs are very rough but should be in the ball park.

Envision the average motorway services, with 30-40 cars recharging, most of which will be well above a 75KW motor and imagine the logistics of providing that sort of electric power service !!

So apart from the power demand of converting all road vehicles to electric there would be the logistics of trunking the power feed to service stations all over the country and Europe of course !!

Don't even try to think of the demand from a motor to power a large truck, the numbers are scary and the batteries would probably weigh more than the vehicle.

Electric power for mass transport it is NEVER going to happen.
Now using '00 Xantia LX HDI, pov spec :(
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Post by Peter.N. »

It can be partly to do with gearing but the main reason for improved economy with a larger engine is that you are using less throttle for a given power output, hence the fuel air ratio is greater and burns more efficiently. You can't do that with a petrol engine as the mixture has to remain pretty constant, about 13/1 I think. The less throttle you use on a diesel the more efficient it becomes, so a more powerful engine will give an improved fuel consumption - as long as you are not using all the extra power.

Peter
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Post by HDI »

Basically the larger engine has more torque so can maintain speed with less effort.
BTW, diesel engines don't have throttles, power is controlled purely by regulating fuel delivery, so at low power requirements there is much more air by ratio than fuel. This is why diesels respond so well to turbo supercharging, much more fuel can be chucked in when a turbo supplies enough air to burn it.
Now using '00 Xantia LX HDI, pov spec :(
My past Citroens :-
'00 Xantia SX HDI, now dead due to accident :(
'99 Xantia HDI 110 Exclusive, RIP :(
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'89 BX TD
'88 AX GT
'79 CX2400 Pallas (scrapped :( )
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2008 Peugeot 207 Sw 1.6 16v hdi. 217k and rising
2010 Peugeot 207 SW 1.6 8v HDi 161k and rising
x 70

Post by citroenxm »

Interesting that HDi - even the New - well HDi's still dont have a "butterfly" but a potentiomiter to Tell the ECU what WE used to tell the Fuel pump with our foot...

The only thing that the DERV engine has to come close to a Petrol is the added High presure fuel rail, and Electronic Injectors... The inlet is still a wide open intake.. :lol:


Paul
Sharing a pug 207 1.6 hdi Sw 16v.
M reg Xm 2.1 td auto exclusive S2 269k and rising
L reg XM V6 12v SEi auto .. Light project

A very sad...
1994 XM 2.1 d auto
HDI
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Post by HDI »

Also the reason diesels require vacuum pumps for all vac operated equipment, as there is no vacuum depression that occurs in the intake manifold of a petrol engine when the throttle is closed.
Now using '00 Xantia LX HDI, pov spec :(
My past Citroens :-
'00 Xantia SX HDI, now dead due to accident :(
'99 Xantia HDI 110 Exclusive, RIP :(
'97 Xantia TD SX
'96 Xantia TD LX
'96 ZX TD
'89 BX TD
'88 AX GT
'79 CX2400 Pallas (scrapped :( )
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Post by RichardW »

Cool eh? 20% more power, 15% less fuel. Isn't that magic????? :lol:

You've got to bear in mind that they will have optimised for the fuel consumption tests so may be no where near achievebale in the real world. I imagine if you use all 170 horses then it will start to drink like anything. They may have put in a longer final drive to drop the rpms a bit, which may well take the edge of the in-gear performance. Unless you rag it of course :wink:
Richard W
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Post by Peter.N. »

When I said 'throttle' I was refering purely to the accelerator pedal. I have been running diesels since 1959 so I know a little bit about them. :D

I fitted a butterfly valve coupled to the pump throttle cable on several Perkins 4/108 conversions I did it to provide vacuum for the brake servo, a little while later British Leyland used virtually the same arrangement on the Sherpa van - I should have patented it :(

Peter
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Post by HDI »

Wasn't doubting your knowledge Peter, I just wanted to clarify for other readers. :wink:

Many people have little knowledge of how diesels work, even some mechanics ! One friend of mine will plunge under the bonnet of any petrol vehicle but stands there in a daze when he see's a diesel !
Now using '00 Xantia LX HDI, pov spec :(
My past Citroens :-
'00 Xantia SX HDI, now dead due to accident :(
'99 Xantia HDI 110 Exclusive, RIP :(
'97 Xantia TD SX
'96 Xantia TD LX
'96 ZX TD
'89 BX TD
'88 AX GT
'79 CX2400 Pallas (scrapped :( )
& a couple of Peugeots !
citroenxm
Posts: 8061
Joined: 30 Dec 2004, 23:10
Location: Somewhere in North Wales, Anglesey
My Cars: M reg Xm S2 2.1td Auto Exclusive. 269k and rising
L reg XM S1 V6 12v Manual SEi
L 94 XM 2.1 TD auto total resto

2008 Peugeot 207 Sw 1.6 16v hdi. 217k and rising
2010 Peugeot 207 SW 1.6 8v HDi 161k and rising
x 70

Post by citroenxm »

Notice on new PSA cars - namely the new Pug 508, the V6 DERV or Petrol lumps appear to have been dropped!!

Mind you, with 4 pot BHP catching up theres absolutly no need for a 6 pot DERV!

Paul
Sharing a pug 207 1.6 hdi Sw 16v.
M reg Xm 2.1 td auto exclusive S2 269k and rising
L reg XM V6 12v SEi auto .. Light project

A very sad...
1994 XM 2.1 d auto
steelcityuk
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Post by steelcityuk »

Just to stir a bit more into the mix, the new Fiat Twin Air petrol engine doesn't have a butterfly in it's induction system either. So what with that and direct injection petrols there's a bit of technology swapping going on.

It's a shame that manufacturers don't quote thermal efficiency figures for their engines.

Steve.
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lussasgraham
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Post by lussasgraham »

has anyone tried one of the chip boxes available on ebay cica £70 that promise more power torque and greater fuel economy?
c5 2,2hdi 2oo2 190,000miles and going strong except it needs a bloody intercooler now-just had a new one fitted and the power has returned!-fap jetwash next
Peter.N.
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x 1199

Post by Peter.N. »

HDI wrote: One friend of mine will plunge under the bonnet of any petrol vehicle but stands there in a daze when he see's a diesel !
Petrol engines have that effect on me :?
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