Best Direct Inj diesel family car for £3K ?

Sounds like you've got a bit of experience of them. Would you say they usually warm up fairly quickly or slowly? Noone answered my initial post on the subject :-(.

Except that back in the pre-ulsp days the 1.8 litre GDI engine had better economy than the standard mitsubishi 1.6 16v MPI.

ULSP and tighter emissions didn't help it out any on the economy front.

-- James

No, most diesels used to have little extra chambers in the cylinder head and the fuel was injected into them. I think they're to swirl the air to get a better mix and smoother burn, but some of the force of combustion is wasted, hence DI being potentially more efficient if you can get a smooth burn some other way.

Well they don't warm up as fast as a petrol that's for sure. My K-series petrol Rover 200 has luke-warm air blowing out of the fan about 30 seconds after it's started, but the diesel takes atleast a couple of minutes, or a mile or two before the air is warm. I like my petrol's quick warm air in the winter for defrosting the hands but am not a fan of the economy though which dives in the colder months :(

That's exactly what I thought you were going to say. You are of course completely wrong but there's nothing new there.

John

On mine car, fuel certainly isn't directly injected into the cylinders, it is injected into Ricardo Comet type combusion chambers in the cylinder head. The combustion chambers have a narrow port connecting them to the cylinders, which restricts gas flow out, reducing noise and increasing turbulance for better (i.e. fuller / cleaner) combustion. The downside is that the extra surface area means lots of thermal energy losses in the cylinder heads i.e. poor performance and economy (even with high compression ratios).

-- James

The diesel is a big heavily made engine with a cast iron block, and good thermal efficiency. The petrol engine is lighter and less thermal efficient. All waste heat that comes out of the engine (to warm up the driver) has to come from thermal inefficiency.

-- James

Explain.

HTFH

John

The original TDdi 2 litre in the Mondeo was a Ford development, but then=20 they passed it over to PSA, who then breathed on it, and increased the powe= r=20 by ~15bph, and a big increase in torque. ISTR the difference was that the= =20 TDCi has ECU control over the boost, and has an overboost feature for=20 overtaking, but the TDdi doesn't have that.

Taken from Dieselnet...

PSA Peugeot Citro=EBn and Ford are also introducing a second-generation 2.0=

- liter engine known respectively as the HDi 2l and the Duratorq TDCi 2.0l.= =20 The new powerplant represents the latest development in the 2.0-liter HDi= =20 family, which has been used in more than three million PSA Peugeot Citro=EB= n=92s=20 mid- and upper-range cars since 1998.

The engine=92s new-generation common rail direct injection system is suppli= ed=20 by Siemens. It manages up to six different injections and delivers an=20 injection pressure of 1,600 bar. The new 2.0-liter HDi/Duratorq TDCi engine= =20 at 136 hp (100 kW) offers 25% more power and 36% more torque (340 Nm at=20

The new engine will be also available in a Euro 4 compliant version with th= e=20 particulate filter.

Pete.

--=20 NOTE! Email address is spamtrapped. Any email will be bounced to you Remove the news and underscore from my address to reply by mail

The original TDdi 2 litre in the Mondeo was a Ford development, but then they passed it over to PSA, who then breathed on it, and increased the power by ~15bph, and a big increase in torque. ISTR the difference was that the TDCi has ECU control over the boost, and has an overboost feature for overtaking, but the TDdi doesn't have that.

Nearly. The first TDdi was in house by Ford. Put into production in the new Mondeo. They then realised it was pants, and passed it to PSA who created the TDCi with the extra whistles like the overboost and 3/4 decent common rail technology. (pump and turbo failures not withstanding!)

Ford had developed the unruly 1.8 Endura DE into the TDdi for the Focus along side the 2litre version of the duratec diesel for the mondeo and when that came back from PSA all singing all dancing they effectively copied and pasted PSA's know-how into the 1.8 unit to create the immeasurably better TDCi.

Tim..

I wonder if PSA are cursing that they didn't put a "No Reverse Engineering" clause into the contract.

Or perhaps Ford did a Cyberdyne (T2) on the 2.0 TDCi "It didn't work, it was smashed, but it gave us some good ideas".

Pete.

I just recently bought a X-plate Xantia HDi, and find it a very nice car. I used to run an N-plate Xantia TD (now belongs to my girlfriend) and the new one improves on it in a number of ways. Economy wise they seem to be the same around town, but the HDi is markedly better than the TD on motorway driving. The HDi is also a lot smoother and less noisy. A lot smoother than the VW TDi PD units, actually.

The spec of the later Xantia's is excellent, as they reached the end of their life. Mine is a Forte special edition and has stuff like Climate Control, electric windows, remote central locking and front fog lights etc. Higher spec ones add stuff like cruise control, rain sensor etc. and are excellent value for money.

The performance is perfectly fine from the 90hp unit for most conditions, as has the advantage of the power coming in quite low down in comparison to stuff like my mum's Golf TDi 130.

I would be careful to buy a good example, with lots of history. Both mine have been one owner cars, and I ran the N-reg for over 30,000 miles and never had any work done on it bar servicing. Watch for buying ones that are around 4 years old, as all the spheres usually need changed around the 5 year mark so budget accordingly.

Any other questions about them just give me a shout!

Chris