Citroen C5 2.0 HDI - Story So Far - Synergy Fitted and MPG

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Citroen C5 2.0 HDI - Story So Far - Synergy Fitted and MPG

Post by timborob »

Hi All

I haven't posted for awhile but here's an update/story on Synergy I had fitted around the end of September.


Well I have now had the Synergy Tuning box on my car for a few weeks and had the chance to give it a good MPG test on a recent run up to Cornwall.

I can say it really does make a difference to the feel of the car and I did an acceleration test which showed a marked improvement on previous test done.

I'm still to test it on setting 9 but setting 6 gave these improvements on the stopwatch :

30-50 mph in 5th gear :
standard a slow 25 seconds ( would like someone else to tell me if this is about right as so slow!)
with box a much more reasonable 14.4 seconds

50 -70 mph in 5th gear
standard 11.5 seconds
with box it improved to 9.8 seconds.

Most of the tests in 4th gear improved the times by around 1 second
which mainly improves throttle response and removed the turbo lag a fair bit.

Putting it on setting 9 did improve it more than on setting 6
so I will definately have to do some more overtaking comparison tests.

The engine now feels silky smooth and doesn't seem to dip like it used to when changing gears.

AND I have now got rid of the poor clutch/throttle biting point feel as I had to rev the car a fair bit to get away smoothly without bogging down as such,This on its own for me proved worthy to buy the tuning box for.


MPG :
After setting an average of 42 mpg on my previous run without the Synergy fitted upto nottinghamshire I thought I'd go into Eco mode but with the box set on setting 9 just to see how it would do.

Well with the car being refuelled to the brim and the trip computer reset I headed off from London at around 6am and watched the trip computer quickly rise to 41 mpg before getting caught in 30 minutes of traffic trying to get over the appley named Kew Bridge,This brought my Trip reading down to 36 mpg which I was not that happy about!

I persisted and found out what the problem was about a mile up which turned out to be a broken down fair or circus lorry actually on the bridge. Once that was past all was plain sailing and I sat in the slow lane at around 50-55mph enjoying my music and scenery to be had in the area.

By the time I was up to around Exeter I was getting a reading of 61.2 mpg.

It did dropped slightly to 59.8mpg by the time I arrived at Newquay some 285 miles and 6 hours and 20 minutes later.

I came back home abit quicker at an average of 60-65mph on the clock and saw the average MPG drop to 57.7mpg by the time I was back on the A205 around the Sheen area.

I've yet to refill and have now covered around 615 miles as done a few local journeys since coming back and my fuel guage is showing just under 1/4 tank and computer reporting around 140 miles of fuel left and an average of 56.5 mpg has been done.

I did note on my last refill that putting the tuning box on had actually made trip computer more accurate for me as it reported I had done 33.6 mpg but i had actually got 34mpg from my brim testing it.

Unfortunately I haven't got £60+ to brim my car again so close to Christmas so will have take the trip computer to be accurate enough.

I atleast now know its possible to get a true 60mpg from my car which is outstanding considering the size of it and better than i thought it would do.

Maybe putting both ZX1 extralube and the tuning box on has improved MPG.

I know it sure has improved the feel of the car and I recommend both upgrades

ATB
Tim
:)
Regards
Tim

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Post by Peter.N. »

Hi Tim

The increase in torque, should, unless you drive it flat out, lead to an improvement in fuel consumption as you have demonstrated which is one of the reasons that the 2.1 Idi engine is so good on fuel as it will pull almost down to tickover.

I have a BMW 5 series Tds diesel which is absolubtly gutless at below 1500 rpm, requiring frequent gear changes, on our recent 2,500 mile drive to and around the north of Scotland it averaged about 47 mpg driven very gently, the 2.1 XM will do over 50 mpg not being driven nearly so gently, so I am wondering if a chip will give much of an improvement in low down torque, or whether this engine is designed to feel like a petrol to pacify your average BMW driver.

Anyway, interesting results.

Peter
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Post by rmunns »

Our Xantia 2.0 Hdi90 did 50mpg on the trip to Corsica and back two weeks ago with 4 adults and full boot. This was filling brim-to-brim and was over about 1300miles.

Fuel consumption figures taken by filling tank to brim are, I reckon, accurate to no better than about 1 or 2 mpg. In fact, since most odometers read high, then consumption figures we take ourselves, unless corrected, are always optimistic.
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Post by timborob »

Peter.N. wrote:Hi Tim

The increase in torque, should, unless you drive it flat out, lead to an improvement in fuel consumption as you have demonstrated which is one of the reasons that the 2.1 Idi engine is so good on fuel as it will pull almost down to tickover....

Peter
Hi Peter

My car does pull so much better now and i can now change into 4th at 25 mph.

Before I needed above 30 mph on a flat or it would really struggle.
Regards
Tim

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Post by timborob »

rmunns wrote:Our Xantia 2.0 Hdi90 did 50mpg on the trip to Corsica and back two weeks ago with 4 adults and full boot. This was filling brim-to-brim and was over about 1300miles.

Fuel consumption figures taken by filling tank to brim are, I reckon, accurate to no better than about 1 or 2 mpg. In fact, since most odometers read high, then consumption figures we take ourselves, unless corrected, are always optimistic.
Hi rmunns

50 mpg is still good over that distance with a full load onboard.

I was solo on my trip other than a holdall and some lightweight fishing gear.

As we can't get really anymore accurate than doing a brim test
I'm happy to get 58 mpg then.

:wink:

My past best MPG record was with another Citroen which was a 1990 1.4D AX which managed 71mpg on a brim test.
Regards
Tim

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Post by citroenxm »

Hmmmm thats interesting then!

If a C5 can reach 55mpg, then a Xantia 110bhp should do much more with a Box... firstly, with half the weight of the C5... will make its much less work for the engine...

How is the Box connected to the car?? Ive got a tuning box that simply connects between each injector and main wiring loom plug ...

Paul
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Post by KP »

AX 1.4 and 1.5d's are great. I drove one back from south wales to warrington years back with my brother in his 1.4 furio c2 and it took less than £10 and still cruised nicely at about 80 leptons plus :D
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Post by citroenxm »

The 1.5d is a far superior unit, theres weakness's with the 1.4d IVE BEEN TOLD....

It still quailifys for the low tax bracket too..

Both do a good 65mpg....

Paul
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Post by Citroenmad »

Interesting results there ... How much was this tuning box, so i can compare it to a reap?

Im guessing this is a visible mod and will be insurance effecting, as its a performance mod?

Ive always been in favour of the remap route than the one of a tuning box. Especially as the place i know does custom remaps for a specific cars ECU, not a generic.

My first C5 had a tuning box on it when i test drove the car, the engine was louder than i had imagined it should be and it sounded a bit rough. I didnt notice that it was hugely nippy, but it was a good quality box. I didnt want the box with the car, when i collected the car it was much quieter and much more like how i thought it should sound. Though the owner didnt report a high fuel usage.

Remaps often offer increased MPG with a much increased BHP and torque figure, usually around 25-35%.

Ive been considering a remap for my C5 for a while, but im yet to get around to getting it done.
citroenxm wrote:Hmmmm thats interesting then!

If a C5 can reach 55mpg, then a Xantia 110bhp should do much more with a Box... firstly, with half the weight of the C5... will make its much less work for the engine...

How is the Box connected to the car?? Ive got a tuning box that simply connects between each injector and main wiring loom plug ...

Paul
I think you will be surprised that the C5 weighs very similar to the Xantia. I too thought it would be a very heavy car, but if my memory serves me right i think they are very similar.

A 1.5D AX is a lower tax bracket? I didnt know the older tax bracket types had a low tax bracket?

I had a 2002 Seat Arosa 1.4TDi for a few years, in fact ive had two. £30 a year road tax, 60-70MPG, sometimes nearer 75 if driven nicely. Very refined and the engine pulled like a train. Ive been in an AX 1.5D, it was good but this was in a different league.
Another great small car is the C1, 60-70MPG, £20 a year to tax, surprisingly spacious inside, great fun to drive, its like a go cart and the engine really makes the car, nice little 3 pot. Brilliant fun and ver cheap, reliable transport.
Chris
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Post by citroenxm »

Chris..

Up to X reg, ALL engines Petrol or DERV UNDER 1500cc's have a set lower tax bracket... and all engines over that are higher...

IIRC, 1500cc or less, its 68 quid for 6 months, and £125 a year, then for larger engines, its 112 for 6 months, and £205 a year....


Paul
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Post by Citroenmad »

citroenxm wrote:Chris..

IIRC, 1500cc or less, its 68 quid for 6 months, and £125 a year, then for larger engines, its 112 for 6 months, and £205 a year....


Paul
Same as my C5 then ... :lol:
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Post by timborob »

citroenxm wrote:Hmmmm thats interesting then!

If a C5 can reach 55mpg, then a Xantia 110bhp should do much more with a Box... firstly, with half the weight of the C5... will make its much less work for the engine...

How is the Box connected to the car?? Ive got a tuning box that simply connects between each injector and main wiring loom plug ...

Paul
Hi Paul
I just checked the weight and a 2.0HDI Xantia is actually heavier than a C5 one!

1436 kg for the Xantia Vs 1385kg quoted for the C5

its strange but true!
:)
Regards
Tim

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Post by timborob »

citroenxm wrote:Hmmmm thats interesting then!

How is the Box connected to the car?? Ive got a tuning box that simply connects between each injector and main wiring loom plug ...

Paul
Sorry Paul I forgot to say the box is connected rather awkwardly to the common rail.

It looked very easy on paper but hard to get your fingers (especially fat ones!) up under the small gap.

I took about 15 minutes try to fit it and almost gave up and was going to ask my wife to do it for me

:lol:
Regards
Tim

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Post by amjake »

Hi All

I have the Synergy fitted to my 2.0 Hdi Auto for about 7-8 months and regularly get 44-45 mpg (brim fills) on 3-600 miles per week perks of an auto I guess!

Have it on setting 6, on 9 had a tendency to spin the wheels!

Haven't timed etc. but the difference is very impressive and the advantage over the remap is you can change the settings or switch it off which I have done on a few occasions to remember what it felt like and at next layby always switch it back on!

For more info http://tuning-diesels.com/ good guarantee and the rover ron very helpful prior to purchase and after for fitting.

I got my garage to fit mine on service as to get to the plug was tight if I remember fuel filter was moved to get to it. Also added ZX1 which one never knows if oil additive makes any difference.

Do use Millers Diesel sport plus whatever its called now and that does make noticable difference and use only Shell fuel who now owe me about 20+ litres since introduced as I don't seem to be getting the extra litre per tankful as per the blurb, One can dream!!

At recent MOT tester asked if I'd had it boosted?

Kevin
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Post by timborob »

[quote="Citroenmad"]Interesting results there ... How much was this tuning box, so i can compare it to a reap?

Im guessing this is a visible mod and will be insurance effecting, as its a performance mod?

Ive always been in favour of the remap route than the one of a tuning box. Especially as the place i know does custom remaps for a specific cars ECU, not a generic.

My first C5 had a tuning box on it when i test drove the car, the engine was louder than i had imagined it should be and it sounded a bit rough. I didnt notice that it was hugely nippy, but it was a good quality box. I didnt want the box with the car, when i collected the car it was much quieter and much more like how i thought it should sound. Though the owner didnt report a high fuel usage.

Remaps often offer increased MPG with a much increased BHP and torque figure, usually around 25-35%.

Ive been considering a remap for my C5 for a while, but im yet to get around to getting it done.

Chris [\quote]

Hi Chris

The Tuning Box was £165 including delivery and is a Synergy CR1
more details here :

http://tuning-diesels.com/Synergy1/tu3all.htm

I brought from here as tried and tested and Uk product with Good support and Warranty.

It is highly visible as sticks to the side of my airbox where i can adjust
it easily if need be but it is staying on setting 9 (the highest setting) for now.

if you know where to get a good safe remap then you can have both fitted
for even better performance in some situations as tuning box improves low end torque and map can be tuned for higher midrange revs.

I recently changed my insurer to Adrian Flux and got the insurance with the box fitted for less than i was being quoted by my previous insurers Elephant /Admiral group.

BTW it was £440 fully comp with PNB

I can assure you Chris adding this tuning box has not increased the sound of the car at all as far as i can make out.
I read alot of older tuning boxes are analogue types and no where near as good as these newer digital ones.

I did also read the top power for our 2.0 HDI is limited to around 135 bhp due to the injectors and pump pressure.

Performance is much better on my car now and more acceptable as found it quite sluggish compared to my wifes Mazda 3 which it can now atleast keep pace with but still doesn't feel as fast but I'm thinking its due to the suspension setup which keeps things smooth with less neck jerking/lunge on pulling away.

SO Chris tell me what MPG would you get from your car on a similar run I made then?
Regards
Tim

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