I thought diesel's were supposed to be hard to stall?
Discussion
ZesPak said:
SoapyShowerBoy said:
If im taking it easy I will rarely go over 2000 rpm in a modern diesel, you just need to get use to it.
Same here,And for the "narrow powerband 2000-2500", that's just rubbish, what diesel have you driven?
Modern diesels have there power from 1800-3800 easely.
One of the reasons a modern diesel is so gutless low down is because it's running so lean that it's in danger of stalling without any help from the driver.
The problem is that diesels enjoy the same stoichiometric ratio as petrol engines and actually have a slightly higher calorific value to the fuel, so should produce more power for a similar compression ratio, cam timing etc. However, have you seen those diesel tractor pullers that blacken out the sky? That's a diesel running around it's stoichiometric ratio. Hence why many modern diesels have the immensly unreliable particle filters, ehich are designed to catch all that smoke and then burn it off whilst the engine is running at a constant high rpm (say, motorway). The problem is, although the diesel apologists (the petrolheaded vegetarian, in my opinion) will deny it, this is a bandaid at best and in day to day running simply doesn't work.
Modern diesels may do more to the gallon than their older equivalents, but they are less reliable, harder to drive and far more fragile.
I voice this a opinion as a breakdown patrol, by the way.
BB-Q said:
Modern diesels may do more to the gallon than their older equivalents, but they are less reliable, harder to drive and far more fragile.
I voice this a opinion as a breakdown patrol, by the way.
I'd go with that. The actual fuel and what it could offer is great. The modern implimentation sucks.I voice this a opinion as a breakdown patrol, by the way.
Agreed with the above thread, modern diesels are suffering from far too much super lean, emissions controls or bad mapping from a drivers point of view. Add in dual mass flywheels & you have an awful combination that would'nt pull the skin off a rice pudding.
Go back 5 or 10 years & you have uber torque at idle, thats off boost torque too though they did smoke a bit more.
Best of the old skool bunch in terms of driveability are:
Pug/Citroen XUD
VAG 1.9 Tdi 90 & 110's
VAG/Volvo 2.5 5 Pot Tdi 140bhp
Wosrt was Ford TD's they were shockingly bad
Best of the new skool
Ford/Landrover 2.4 TDCi if they sped up the "Fly by Pigoen" throttle delay
Go back 5 or 10 years & you have uber torque at idle, thats off boost torque too though they did smoke a bit more.
Best of the old skool bunch in terms of driveability are:
Pug/Citroen XUD
VAG 1.9 Tdi 90 & 110's
VAG/Volvo 2.5 5 Pot Tdi 140bhp
Wosrt was Ford TD's they were shockingly bad
Best of the new skool
Ford/Landrover 2.4 TDCi if they sped up the "Fly by Pigoen" throttle delay
The 1.9 PD VAG has unit injectors instead of common rail (Mk3-4 Golf.. think the newer 2.0 tdi in the Mk5 is common rail?). It takes time to ramp up the injection volume so torque from idle is poor. If you point it up a hill while on the go and roll off the throttle it will drive up a mountain on idle (do this every day as my farm track is so bad).
The common rail ones should be better but I am still stalling once in a while after 40k miles
As an aside.. if you look under these tdi they have a 5hp fuel cooler on the return line.. that is an indication of how much power it takes to drive high pressure pumps required! If they could improve the pump efficiency they could give another 2-3 hp at the wheels and likewise on economy.
The common rail ones should be better but I am still stalling once in a while after 40k miles
As an aside.. if you look under these tdi they have a 5hp fuel cooler on the return line.. that is an indication of how much power it takes to drive high pressure pumps required! If they could improve the pump efficiency they could give another 2-3 hp at the wheels and likewise on economy.
cptsideways said:
Go back 5 or 10 years & you have uber torque at idle, thats off boost torque too though they did smoke a bit more.
Best of the old skool bunch in terms of driveability are:
Pug/Citroen XUD
VAG 1.9 Tdi 90 & 110's
VAG/Volvo 2.5 5 Pot Tdi 140bhp
Best of the old skool bunch in terms of driveability are:
Pug/Citroen XUD
VAG 1.9 Tdi 90 & 110's
VAG/Volvo 2.5 5 Pot Tdi 140bhp
My idle is a bit high at 1k but it'll pull away at 1.25k with no fuss. You can also leave it in 3rd gear as long as you're already in motion and it'll go to about 15mph without touching the pedals and won't stall...
If you leave a good enough gap it makes stop start driving much less of a ballache
ZesPak said:
SoapyShowerBoy said:
If im taking it easy I will rarely go over 2000 rpm in a modern diesel, you just need to get use to it.
Same here,And for the "narrow powerband 2000-2500", that's just rubbish, what diesel have you driven?
Modern diesels have there power from 1800-3800 easely.
Best wishes all,
Dave.
Never had a problem with my old Fabia vRS in 43k miles. It seemed happy to trickle away at silly low revs. Maybe, in the quest for some "efficiency" gain, they've done something "bad" to the new generation.
Current D5 is impossible to stall................but maybe that's 'cos it's mated to a 6-spd Geartronic, eh ?
Current D5 is impossible to stall................but maybe that's 'cos it's mated to a 6-spd Geartronic, eh ?
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