Dangerous Euro IV side effects - Dan J
Euro IV emission regs which are present on most mainstream petrols now and will be enforced in a couple of years time contain the helpful little addition of throttle damping.

Personally I find it hard to see how this helps exhaust emissions but what it certainly does is affect the way you expect a car to respond.

My 2.2 Vectra is Euro IV compliant and the minor delay is almost a quirk and simply means in pulling say, into another motorway lane which is quite tight, I simply need to blip the throttle a little sooner rather than later. But having driven several Corsas recently, one Euro III, one Euro IV the difference is appalling. The delay in the car responding to a sharp press on the throttle on the new regs on a car with a small engine is nothing short of frightening - By the end of my day with the Corsa I was frightened to pull out into traffic as the car would just not pick up for a second. The older Corsa was quite nippy.

Chatting with a mate of mine who has just changed his Astra for a newer one with Euro IV (gone to 1.8 16v from a 1.6 16v) and whilst there's no denying once the car's on the move it's peppy and a brilliant drive, as you press the throttle from idling you get absolutely nothing for half a second.

Is it just me or is messing with the way a car responds, or at least you expect it it, not a particularly safe thing to be doing?
Re: Dangerous Euro IV side effects - Richard Hall
Presumably the aftermarket chip suppliers will be able to program out the throttle delay, without affecting emissions at idle? Buy shares in Superchips, now. Small cheap cars have had a form of throttle damping for years - the result of using underspecified electronics in an attempt to keep the cost of fuel injection down to the same level as a carburettor. I owned two Citroen AX10s, built a couple of years apart - the earlier one (Solex carburettor) was fine, but on the later car with monopoint fuel injection, the delay in throttle response was very noticeable, as the ECU struggled to work out what commands it was supposed to give to the injector. I have driven small Fords, Fiats, Vauxhalls etc which had the same problem (a Punto was memorably awful), but I haven't yet driven a Euro IV vehicle, and I don't want to.
Re: Dangerous Euro IV side effects - markymarkn
I found that on a new Astra (1.4 - no bottle at all) I drove as a hire car.

Very disappointing drive. I prefer to drive my 12 year old astra cd.

Re: Dangerous Euro IV side effects - John S

Odd. I've test driven a couple of new Astra 1.6 16v recently, and not found the problem. Just bought a Euro IV 1.8 16v, and the throttle response is fine. To be absolutely fair, I think these systems probably damp out violent throtle movements, but so far I haven't encountered any real lag. No obvious indications it's fly-by-wire, although we're still treating it gently, and haven't used full throttle, so I'll have to see how it goes.

I wonder if not all cars have this characteristic.


Re: Dangerous Euro IV side effects - markymarkn
Maybe it was tweak because it was a hire car?

Perhaps to stop people nailing quite so hard everywhere :-)

Re: Dangerous Euro IV side effects - Iain C
Well, the 2 Euro IV cars I have driven (both new type but well run-in) - a Corsa 1.2 16v and Astra 1.6 8v have been strange - its especially noticable when pulling off - either no revs or lots! The Astra also felt very obviously drive-by-wire when crusing (totally different to the largely similar old 1.6 8v with single point injection) although it did feel a little more torquey at low revs when it had actually decided I wanted to go! Thats probably due to the multipoint injection though...
Re: Dangerous Euro IV side effects - markymarkn
insert 'it' between nailing and quite.


Value my car