2.1 TD Torque curve

[Peter.N.]

No, they are 'old skint man' driving figures generally recorded on our anual Scottish trips. Driving at not much more than 60 mph and gently - I did my boy racing when I was younger and certainly wouldn't have got those figures then. They are based on our journey between Tesco at Axminster and at Inverness, the XM will consistently record over 50 mpg and sometimes 55 mpg, the 406 this year made 60.2 according to the read out, should have been better but the speedo kept going on holiday. We filled up in Derbyshire on the way back and the 'distance remaining' readout said 1212 miles!

I have not really done a long journey in a 1.9 but we used to average 40+ round here but I have been told that they can do 50 mpg, probably driven in my style they are certainly not as economical as the 2.1.

Peter

[steelcityuk]

I would think that the reason PSA didn't use a 12v design was partially down to the cost of redesign needed to make it a direct injection system, if you're spending all that money go straight to a 16v for the performance engines. Depending on the intended location and route of the injector on a 12v head an inlet tract or valve stem could be in the way.

Steve.

[Geoff Lebowski]

I would think that the reason PSA didn't use a 12v design was partially down to the cost of redesign needed to make it a direct injection system, if you're spending all that money go straight to a 16v......

Steve.

Good point. I have to say I'm not impressed with my HDi at all, both performance wise and consumption wise.
Peter is your 406 an 8v 110bhp?

[Peter.N.]

Yep, that seems to be the most reliable one with quite a few for sale with 300,000 + miles on.

I have just been out in the XM again today Geoff to take it for MOT - which it failed I carefully observed when the power started coming up and at 1400 rpm it was pulling strongly enough to accelerate up quite a steep slope in 4th, that's something the 406 won't do for another hundred or two revs.

Peter

[Dieselman]

I suspect the reason the original HDi was 8v is because the space required to mount the central injector coupled with direct injection diesel engines not revving as high as indirect ones, meant that there was less requirement for good breathing at higher revs....

....and cost..

[Dieselman]

A 1.9 should fit as the XU series blocks are all the same be it petrol or derv and the 2.1 is just a stroked 1.9 anyway, still no point putting a 8v head on a derv though.

D

I hadn't actually checked the bore size. That would explain why the 2.1 is so torquey low down.

[Geoff Lebowski]

Yep, that seems to be the most reliable one with quite a few for sale with 300,000 + miles on.

I have just been out in the XM again today Geoff to take it for MOT - which it failed I carefully observed when the power started coming up and at 1400 rpm it was pulling strongly enough to accelerate up quite a steep slope in 4th, that's something the 406 won't do for another hundred or two revs.

Peter

Your comparison between the XM and 406 sounds like how I would of described the comparison between my Xantia and C5. So whilst I agree with you, the comparison seems at odds in that the peak torque of the HDi is 250 rpm lower than the 2.1 whilst actual performance would suggest otherwise.

Whilst the 12v head could be better than the 8v, it'll still be no slouch, and especially so in the BX which is as light as a feather (well - sort of!)