I was in a slow moving queue today and to keep the car rolling, I left a gap ahead, rather than follow the stop/start antics in front. I was covering the clutch pedal in 1st gear to stop stalling the engine, but as I approached a slight incline I realised the car was continuing without me touching the accelerator, and didn't seem like it was about to stall. When I reached the flat I checked the speedo and was doing about 6kph. I don't get much engine braking when selecting low gears downhill, compared to my previous 10 year old car, and was wondering if idle speeds are generally higher now for emissions purposes, or is it just the 1.4 TSI engine's torque range (or the 6 speed gearing) allowing it to pull at 'idle'?

Modern cars tend to do this, they have like an anti stall mechanism, that's the best way I can describe it, as they're designed to idle and maintain a set RPM without throttle input. Especially with electronic throttles, which has a simulated dashpot to smooth out gearchanges

I believe it is an anti stall mechanism which provides more fuel to maintain the revs at the idle speed.

I believe it is an anti stall mechanism which provides more fuel to maintain the revs at the idle speed.

I think you'll find adding more fuel without adding more throttle will do nothing but make it run rich and potentially cause borewash ( and knacker your cat )

It must have an influence on the throttle butterfly too

I think you'll find adding more fuel without adding more throttle will do nothing but make it run rich and potentially cause borewash ( and knacker your cat )

It must have an influence on the throttle butterfly too

Yep, the thottle is fly by wire, hence the ECU can open the butterfly valve without any accelerator input.

I think you'll find adding more fuel without adding more throttle will do nothing but make it run rich and potentially cause borewash ( and knacker your cat )

It must have an influence on the throttle butterfly too

Thats what I meant just not very well worded, sorry

Like 30mph in 5th being achievable on the flat without touching the throttle ( or slipping the clutch) in the old VW TDI engines. the electronics feed in the diesel as needed

When driving in slow moving traffic I do not need to touch the throttle, just ease up the clutch

and trundle away. Better than faffing about stop/starting when you can

30mph???

Stuck in a huge tailback of traffic in heavy snow last year I was trundling along in 5th at about 15-18mph!!! I reached a hill and it wasnt very happy, so I dropped to 4th and went up at about 12mph.

If I recall correctly. yes 30mph in 5th & def on the level cos it was along a beach.

Cheers

M

If I recall correctly. yes 30mph in 5th & def on the level cos it was along a beach.

Cheers

M

Yep, that's not far off for some TDIs in top.

Modern cars tend to do this, they have like an anti stall mechanism, that's the best way I can describe it, as they're designed to idle and maintain a set RPM without throttle input. Especially with electronic throttles, which has a simulated dashpot to smooth out gearchanges

I have managed to stall the car a few times under normal driving conditions, usually anticipating turbo level of power when not in the turbo rev range, so I was quite surprised it was pulling in 'idle'. If it's intended to do that, I'll let it do the 6kpm crawl when appropriate. It is a bit like a 'cruise control' though. I'm much more used to balancing the 3 pedals on a crawl, so more likely to hit the brake and forget the clutch, when I'd normally have selected neutral by that time.

Just be careful not to do this at too low revs as you can put a lot of stress on the engine, above 1250rpm should be fine,