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2.5TD vs 3.0V6

Posted: Mon Jun 05, 2017 11:59 am
by Pshemsky
Hi Guys. I do love my 2.5 because is just perfect for me. Right power, mpg, shape and style. But always somewhere deep in my heart was a small spark of love towards V6. Never had pleasure to drove one of these monsters so would like to hear some opinions from more experienced xm users. How much more difficult is to maintain V6 compare to 2.5? Is spare parts market bigger than diesel one? Which engines and gear boxes are better and more reliable? Is there big difference between early models and later ones?
Many thanks for all information.
Regards
Prem

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Re: 2.5TD vs 3.0V6

Posted: Mon Jun 05, 2017 2:26 pm
by Dean
In terms of Access to stuff I think the early PRV V6 is probably the best, it looks packed but access to everything is pretty reasonable, the 2.5 is a little more compact and with a much higher component and pipe count.

Parts are probably about the same between 2.5 and PRV now, scarce to impossible.

The later ES9 V6 will be more powerful, more fuel efficient, more reliable and with fantastic parts availability so you would expect the sane person to choose between 2.5 and ES9.

D

Re: 2.5TD vs 3.0V6

Posted: Mon Jun 05, 2017 3:52 pm
by White Exec
Hi Prem,

What a question! - But a good one, all the same.
I think owners of each will cheer for what they have, and I suppose that's understandable. They'll have chosen it, got to know it, and probably got pretty involved with what makes it tick. Some folk are incurable collectors . . . and often of the same type.

Power figures tell a story:
3.0i V6 / 2.5TD

bhp: 194 @ 5500rpm / 130 @ 4300rpm
torque: 197 ft.lbs @ 4000rpm / 217 ft.lbs @ 2000rpm
weight: 1591kg / 1580kg

The V6 can get to 60mph quicker, and top speed is 18mph more than the 2.5's listed 125mph max, but who drives like that? or can afford to?

The V6 is smoother at very low revs (eg hard throttle below 1500), but the 2.5 smoothes out perfectly by 1200, and then peak torque available at 2000, no need to run the engine up to twice that (or to hold a lower gear) to come into the peak torque band. Both engines are equipped with balancer shafts, so are smooth and vibration-free in all normal circumstances.

With lower rpm comes longevity, and with the gearbox too. Forum pages detail the need for on-going care of the automatics, costly repairs, and the need to be super-vigilant over fluids and filters. In contrast the 5-speed manual box (option on the V6, no choice on the TD) is a splendidly reliable and long-lived piece of engineering. The manual change, together with its upmarket pull-action clutch, offers some of the easiest manual changes to be had (for the era), especially with the correct GL-4 oil in it.

Fuel consumption. Our 2.5 averages 32-33mpg (mixed urban, mountain track and motorway), and 38mpg on local motorway commuting. For international travel, it returns 41-42, and that's at speeds averaging 60mph. Others will be able to list V6 figures, but they won't read like that.

Lots of cylinders is wonderful, and I look back fondly to the sound and smoothness of a Rover V8 - both auto and manual. But I don't look back with fondness to the 17-24mpg that went with it.

We decided we preferred diesel a long time ago now. First was the BX19RD - our son had a BX19GTi - and the comparison was interesting, as was the amount of fettling needed to keep the GTi mobile. 44mpg from the RD, a bit over half that from the GTi. Hmm...

So, I'm glad not to have to look after plugs and leads, HT and distributor, ignition modules, in-tank fuel pumps, and all those bits. Exhausts on diesels last longer, and pumps and injectors are fairly bombproof, if you keep the air out. Routine servicing almost boils down to just two items: oil + filter.
Put aside an auto box, too, and the transmission is almost forgettable.

But it's not a simple as that. Just look at the numbers on our Members' Cars list...
viewtopic.php?f=19&t=7089&p=81829&hilit=malaga#p81829
Out of the 63 XMs there, petrol and diesel split almost equally, 33 vs 30, just like global sales (181k vs 151k).
19 are V6s, 14 are 2.0i
25 are 2.1TD, and only 5 (8%) are 2.5.

This small number of 2.5s is interestingly almost exactly the same as the global proportion of 2.5s produced (7%)...
viewtopic.php?f=2&t=7833&p=93060&hilit= ... res#p93060
...22,785 hatch and estate.

Easy to work on, and access? No, but neither is any XM, with well-stuffed engine bays. The 2.5 is towards the sod-awkward end, with a good few jobs (new belts, replacement starter, turbo access) not a lot of fun. The upside is that these jobs don't need tackling very often, and overall reliability - if you look after basic servicing - is extraordinarily high.

I'll let someone else tell the V6 story. They'll be no shortage of detail, I'll bet! ;)

Re: 2.5TD vs 3.0V6

Posted: Sat Jun 10, 2017 1:58 pm
by Pshemsky
Thanks for information guys. Think that I'll stay with 2.5. At the end of day I need every day use car and in that subject diesel is much better option. Maybe one day I'll have a chance to hear and pleasure to do a test drive on V6 :)

Re: 2.5TD vs 3.0V6

Posted: Sat Jun 10, 2017 5:47 pm
by Ciaran
What you need my friend is a V6 diesel :)

CiarĂ¡n

Re: 2.5TD vs 3.0V6

Posted: Sat Jun 10, 2017 7:16 pm
by White Exec
From PSA, those came a bit too late for the XM.
Now, for a much more interesting transplant, Dean . . . :P

Re: 2.5TD vs 3.0V6

Posted: Sat Jun 10, 2017 7:29 pm
by Dean
........I don't do diesel I'm afraid Chris............... :D

D

Re: 2.5TD vs 3.0V6

Posted: Sat Jun 10, 2017 8:02 pm
by Ciaran
:lol:

Re: 2.5TD vs 3.0V6

Posted: Tue Jul 11, 2017 7:56 am
by PasqualeN
Dean wrote:In terms of Access to stuff I think the early PRV V6 is probably the best, it looks packed but access to everything is pretty reasonable, the 2.5 is a little more compact and with a much higher component and pipe count.
Same here, that v6 is lovely!

Re: 2.5TD vs 3.0V6

Posted: Tue Jul 11, 2017 9:20 am
by citroenxm
The zf4 hp20 auro box in the v6 is... delicate. . Anything after 100k with no history is on borrowed time. Claimed to be a sealed for life box they arent and do need oil services to live long..

The older prv engines up to 1996 used the 4 hp18 box which is very simply serviced and if oil changed every 6k can do 200k no problem..

Exhausts on v6 are or were dealer only. Motor factors never made them so come replacment you need deep pockets or have a specialist fabricate a stainless one.. 2.5 td ones are available.