Immediate difference between C5 and Xantia

[frenchcarnut]

I think the Xantia was better around town and certainly fantastic for parking, much better than the C5.

Prefer the solidity of the C5 on the long run and motorways though.

C5 electrics much more reliable thus far

C5 2.0L Diesel is a dream compared to my 16v 1.8 Petrol Xantia. No more 'pinking' and rattles, and no more complete meltdown when the aircon is on (which is rare due to green issues)

C5 lack of Haynes and workshop manual doing my head in though

PS - Anyone recommend decent SVO conversion for C5?

[Homer]

aircon is on (which is rare due to green issues)

Why?

I tried running the Xantia with aircon on and off and did not note any difference in fuel consumption.

If you have the windows open then the extra drag would have more effect.

[frenchcarnut]

aircon is on (which is rare due to green issues)

Why?

Def. increase in consumption with mine both Xantia and C5

[KennyW]

Hi there gang,

Just returned from France with a copy of the Revue Technique Automobile book for the Xantia and for your info their book for C5 Diesel (2001)
Revue No 654 and code 19417

Address for company

20,rue de la Saussiere,
92641 Boulogne Billancourt Cedex
Fax 01 46 99 32 40
Tel No 01 46 99 24 08 for customer relations.

Cheers

Kenny

[alan s]

aircon is on (which is rare due to green issues)

Why?

Def. increase in consumption with mine both Xantia and C5

I would suggest that in a modern car the difference should be minimal if the system is being used correctly.
Two examples comes to mind in my case.
BX16Trs using air/con 7.3L/100 klms with air con operating, 7.2L/100 klms without.
This was done over the same trip on consecutive days with the same load.

A 2000 klms trip in extreme heat (minimum 35 maximum 50 degrees) with 5 people in a 2.0i Xantia manual with a boot full of luggage and air/con on all the way, averaged 33 mpg.

I would suspect that any noticeable variance in fuel consumption could be more likely to be due to the lower ambient temperature on the days that the air/con was not used rather than load created when it was.
If "green" issues are a problem, then perhaps a switch to a hydro carbon "green" refrigerant (Greenfreeze) might be an option when the warranty runs out, thereby not using an ozone depleting substance (which can leak into the atmosphere if the air/con gets too little use) but also has the advantage of operating at lower pressures thereby reducing load on the air conditioning system.



Alan S

[Kowalski]

The figures I've seen from the AA, say that aircon can add between 5% and 10% to your fuel consumption, having a window open can do something similar....

[alan s]

The figures I've seen from the AA, say that aircon can add between 5% and 10% to your fuel consumption, having a window open can do something similar....

Those tests need to be put into context.
In a city environment I have no doubt they might be close depending on the car, the design of the system and the driving conditions. Forgetting the "scientific tests" which I proved incorrect on practical experience (above), I'll still defy anyone to drive in 50 degrees in a dark coloured car with the windows wound up and no air/con. and risking leaking ozone depleting substances into the atmosphere due to lack of use won't be a better option than using the air/con for its intended purpose.


Alan S

[Peter.N.]

It depends largely on how you drive. If you thrash the car the, the aircon will make very little difference to an allready poor fuel consumption, if you drive gently you will notice the difference. The compressor consumes several horsepower so it is bound to have an effect on the fuel consumption.

[Mandrake]

Oh goody, this old chestnut again.

Honestly, I don't notice any statistically meaningful difference in fuel consumption with air conditioning on or off in my Xantia, so I don't give it a second thought.

If it's too hot, turn it on, better than getting overheated while driving and getting sleepy or even passing out....

On the other hand I bet driving at 100Km/hr with windows down doesn't do much for the drag coefficient...

Regards,
Simon

[deian]

I'm with Simon on this one, no point worrying about the fuel consumption, if it's hot, air con on, if it's cold air con off, simple, if i'm worried about fuel consumption then i will just drive with a lighter foot and overtake only if necessary, air con shouldn't be an issue really.

It's cheaper to run a car with aircon than a car with windows open.

[frenchcarnut]

Oh goody, this old chestnut again.

OH GOODY a hint of sarcasm. Actually Simon it's whatever cuts your mustard on green issues. On my old petrol Xantia it drank fuel when the unit was switched on, take it or leave it as fact, but it did. On my C5 the consumption goes up but nothing to worry about. The issue above for me was more about the horrible performance of my old petrol when the unit did kick in.

The point about the green agenda is that if everyone stopped using their vehicle aircon then the difference would be appreciable, however, I'm not here to preach to anyone just offer my thoughts, which clearly you don't agree with. So that's the end of that OLD CHESTNUT.

It's a good job we're not all the same

[alan s]

Oh goody, this old chestnut again.

On my old petrol Xantia it drank fuel when the unit was switched on, take it or leave it as fact, but it did. On my C5 the consumption goes up but nothing to worry about. The issue above for me was more about the horrible performance of my old petrol when the unit did kick in.

I think the point you're missing, ignoring or avoiding is that the problem was your air conditioning was not operating as it should. Possibly air in the system, overcharged, filter needing replacing, dirty condensor or fans not operating correctly can all cause that problem.
As I outlined in previous responses, the driving conditions can have a bearing more so than driving style and logic says that if I can live in a hot climate and you live in a much cooler one, then if anyone should feel a difference in power and see a difference in consumption, I should, yet as I've quoted actual figures, this shows little if any difference.
The only other explanation would be that the systems used in the UK domestic market were engineered to different specifications to those exported to warmer climates, but that is highly unlikely. I'd still opt for your old car to have been needing the air con system being serviced as it was obviously not operating as it should.


Alan S

[frenchcarnut]

Hi Alan, thanks for the response. No the car was maintained pretty well up until I had had enough of the ABS sensors and needed a new car pretty quickly for personal reasons. It may have been the design of course, but I had a major service at about 55k miles and Citroën themselves denied any issue with the A/C.

I think it's pretty common knowledge that A/C has the following disadvantages:

1) decreased responsiveness and acceleration due to deviation of power to compressor
2) increased fuel consumption - especially in maintaining above
3) efficiency of cooling system reduced
4) added complexity and weight to overall design
5) heat being pumped out into the atmosphere increasing one's carbon footprint. Multiply this (and 2) by many across the world and the problem becomes globally detrimental.

Of course for many the advantages outweigh the negatives, but for me I'm happy to take my choice

The figures I've seen from the AA, say that aircon can add between 5% and 10% to your fuel consumption, having a window open can do something similar....

I agree Kowalski and take that on personal experience. However, when driving in town and at slow speeds I think the drag versus A/C coefficient is minimal and only really kicks in above 30mph.

My view is that if I can bear not to use the A/C and use vents instead then I do. Up to 25 °C is okay for me from memory!

[alan s]

Don't intend this developing into a long winded saga, but in all fairness:

think it's pretty common knowledge that A/C has the following disadvantages:

1) decreased responsiveness and acceleration due to deviation of power to compressor
2) increased fuel consumption - especially in maintaining above
3) efficiency of cooling system reduced
4) added complexity and weight to overall design
5) heat being pumped out into the atmosphere increasing one's carbon footprint. Multiply this (and 2) by many across the world and the problem becomes globally detrimental.

The "common knowledge" may be correct in some instances, but in most, the common knowledge is best described as "urban myth" due to too much of this info being based on either old outdated designs (back in the days of reciprocating compressors, R12 and hose clips to hold the hoses to the fittings) in reality, and I AGAIN point to the figures I quoted previously.

1) Decreased power and responsiveness blamed on power required to drive compressor.

The compressor does not run constantly and in any case can be turned over easily by hand.
Wind pocketing inside the car has been known back in CX days to be strong enough to blow rear quarter windows out; which requires the most power to achieve?
In a properly maintained modern system (something fitted since say around 1987) The air/con coming onto cycle should be barely noticeable to the driver unless, you are in a heavy traffic situation on a very hot day.

2) As said previously, if the system is operating correctly these days, this is not a major issue.

3) Totally incorrect. With the fans running all the time, the overall engine temperature is reduced. Again, only if the air/con system is faulty would the engine increase in temperature, in fact, I know some who have cooling issues with their cars who deliberately run the air/con on hot days to keep engine temp down.

4) Added complexity is going to happen regardless of anything you fit; as for weight, how much does an alloy compressor weigh along with a couple of aluminium coils? 20kgs at the outside? about the weight of a box of groceries.

5) Heat being pumped out into the atmosphere increasing one's carbon footprint.
You've lost me on this one.
If the engine temperature is normally running at 95+, with the air/con fans, reduce this to around 80 which is where it commonly sits, this hypothesis only becomes an issue if the above hypothesis about cars getting hotter is correct, however, even if it were a case that the temp didn't reduce when the air con was on, the thermostat and thermo fans in the engine should keep it running at around 95/100 mark anyway and the only way it could then increase the carbon emissions would be if the theory that there was a big increase in fuel consumption, which in my case was .1L/100 klms or approx .4 of a MPG.

Rather than an old chestnut I tend to look upon this as an interesting topic, but I think in all fairness, I should explain that by trade I am a fully qualified refrigeration and air conditioning mechanic who did a 5 year apprenticeship as well as a theoretic course in conjunction plus I have had extensions to my trade ticket, and over here the environmental aspect is far stricter than controls you guys have over there so this topic has been widely discussed and theories debunked many times over the years.
Your statement that your Xantia "drank petrol" when the air con was turned on prompted my comment that you had a faulty system and I still maintain that was the case, particularly if the points you mentioned above related to the way your system was operating.
I was not referring to the general maintenance of your car as I have no doubts it was up to scratch, but unfortunately since DuPont and ICI swung the R134a deal, car air con servicing overall and worldwide seems to have been taken out of the hands of trained tradesmen and in too many cases placed in the hands of those who could afford to buy all the fancy gear, pay all the fancy licence fees, do "Mickey Mouse" college courses and write all the fancy invoices, with the result that the standard of repairers seems to have fallen considerably as I see from postings we get on here at times and I feel that possibly, this may have been where your problems arose with the Xantia.
If the C5 were to require servicing, then if the same set of circumstances were to then apply to the C5 system due to incorrect servicing, I have no doubt the problems of the Xantias air would repeat itself.


Alan S

PS. I'll pull my head in now as this thread is beginning to get a life of its own far removed from the original posting of differences between two models.

[frenchcarnut]

Alan I'm sorry but you appear to be in denial.

(1) there will still be an appreciable drop in responsiveness - especially in petrol engines. Mine was perfectly maintained thanks.

You merely brush (2) aside whilst all the evidence points, as Kowalski alludes, to an appreciable increase in consumption. If that equates to 3 to 6 litres out of a full tank every fill up multiplied over a year and over many cars, then that's a lot of wasted fuel.

(3) May be 'totally incorrect' for you, but I doubt it. Simple physics and thermodynamics would dictate that the extra heat obtained through, what is effectively a fridge with an open door, creates extra strain on the cooling system. Not only that, the extra fans you quote licking into action require more power which in turn generates more heat and increases fuel consumption.

(4) Of course, but you can't exclude it. That's why in the UK there's been advice handed out to remove unwanted crap from the boot of one's car.

(5) Again from (3) and has nothing to do with engine temperature per se. An A/C system is basically a fridge. Go to the back of your fridge and check the heat. It is that heat and any heat from ancillaries in maintaining the correct temperature of your engine which increases your carbon footprint.