C5 HDi how to improve a 90bhp version

[KP]

Is there a way(without chipping) of improving a C5 90bhp HDi?

My dad has got one and im sure its the 90 as i cant see any intercooler or associated pipe work.

Is it possible to improve the engines in these at all?
If anyone has driven both is there much difference?

I take it being a newer car it will be taxed on its output but does this mean if the exhuast starts to fail it will have to have its centre section piecereplaced as original or would i be able to remove any of the centre box's at all?

Also it currently sits on 195/65/16 tyres.
does anyone run theirs on 205/60/16's at all as i notice they aren't as common a size and 2 of the tyres deffo needs replacing.

PS its a 51plate, 43k miles, service history, quite clean inside and out and was all done for about £2700 i think. is that a good price from a dealer for one?

[rabenson]

Why not consider chipping? if you go for a mild remap you can get some good performance gains without compromising longevity. There are a few companies that will sell an add on box that does this but which can be removed without affecting the orginal stored mapping. I'm considering one myself for my 90bhp xsara but not quite decided yet...

There's no cheaper or more effective way to provide real performance/ efficiency gains

[KP]

Not really looking at spending more than £50 you see

Think he might swap over the K&N Panel filter from his Xantia to the C5 as its a cost saving device as well

He was due to decat the 2.1 but now its up and running again he's going to sell it instead as he quite likes the C5 and the extra space in the engine bay

[nick]

I take it being a newer car it will be taxed on its output but does this mean if the exhuast starts to fail it will have to have its centre section piecereplaced as original or would i be able to remove any of the centre box's at all?

If it was registered after March 2001, which I think all C5s will be, then yes it will be taxed on its official CO2 emissions figure. However, there is currently no system in place for this to be amended, regardless of any mods carried out, so in theory you could stick a 5 litre V8 petrol engine in it and it would still be taxed as an HDi 90

[mooseshaver]

If it was registered after March 2001, which I think all C5s will be, then yes it will be taxed on its official CO2 emissions figure. However, there is currently no system in place for this to be amended, regardless of any mods carried out, so in theory you could stick a 5 litre V8 petrol engine in it and it would still be taxed as an HDi 90

What would happen at MOT time? The car would have higher emissions than its supposed to. Would they ignore it as its modified.
Now where can I get a nice big engine to repalce my 2.2 diesel

[CitroJim]

What would happen at MOT time?

No problem, as long as it passes the smoke density test it'll be OK. CO2 is not tested at MOT time

In fact, CO2 testing is such an involved job, it is likely never to be introduced for MOT testing...