Common rail (CR) v Pumpe düse (PD) diesel [Archive] - VW Eos Forum : Volkswagen Eos Forums

: Common rail (CR) v Pumpe düse (PD) diesel


davidp
10-20-2008, 11:11 PM
Has anyone driven an Eos with the older PD Diesel and the new common rail diesel and able to compare them. Just wondering if there is much difference as the new CR engine is supposed to be quieter and smoother, or is that just marketing hype?
Cheers, David

cambourne7
10-20-2008, 11:46 PM
I test drove the desiel engine and my new car is the common rail and i do think its quieter. Apparantly it also uses less (a tiny bit less) oil.

silvershadow
10-21-2008, 01:33 AM
I have not driven one of the MY09 common rail diesels as they have only just arrived in Australia this month and we will pick up my partner's Eos this saturday :) :) :) .

It is my understanding the main differences are in engine technology rather than performance - the common rail units make it easier to achieve emission control requirements and also allow better fuel economy by using more precise control of fuel injection volumes. The possibility of remapping the electronics to achieve higher power/torque outputs will probably increase over the next year or so

Apparently, the big downside is that the current common-rail system is not suitable for bio-diesel other than a 5% bio blend, the VW fuel recommendations and warranty exclusions reflect this situation. I have not been able to find out why so far but speculation suggests it is related to the relatively greater "compressibility" of bio-diesel compared to mineral diesel meaning it is difficult to obtain optimum fuel/air ratios using the current common rail technology. I also suspect soot generation in city driving conditions clogging the standard DPF filter might also be a reason.

Perhaps I am naive but given the strong possibility of government-mandated bio-diesel fuels in the future; I would be surprised if VW would introduce technology that cannot be readily converted to bio-diesel in the immediate future.

cambourne7
10-21-2008, 10:36 PM
just checked the inside of the fuel cap and there is a big warning saying no bio desiel :confused:

ajcordeiro
12-01-2008, 05:55 PM
I would like to give you my feedback as owner (also) of a Passat 3BG variant 1.9 tdi 130 cv ...better motor in low rpm and tiny difference in high rpm, so you get better response with higher gears, even in 6ª gear it has power.

Do you know if there is been some software updating for the lake of power below 1500 rpm in the 2.0 tdi PD 140? I'm asking this as at least for Passat 3C there was 2 software updates.