Germany’s much-hyped “diesel summit” has done little to clear the noxious air between the country’s auto industry, politicians and motorists.

Opposition politicians and consumer and environmental groups have attacked Wednesday’s deal as a lazy compromise that will bring minimal air quality improvements in cities and little clarity for millions of diesel drivers.

The “voluntary” agreement will see VW, BMW and Daimler offer software fixes – to reduce by noxious emissions by around 30 per cent – for 5.3 million diesel cars. Strip out the 2.46 million cars that VW has already been ordered to update because of manipulated software, and just 19 per cent of 15 million diesel cars are eligible for the fix.

German government ministers, who are facing voters next month, presented the software fix and financial incentives to scrap older models as an “important first step” to improve air quality in major cities and avoid court-imposed diesel bans in the coming months.

But VW chief executive Matthias Müller, with nods from BMW and Mercedes maker Daimler, made clear this was their final offer. They dismissed as “impossible” politicians’ hopes for more effective, and expensive, hardware retrofits.

Wednesday’s deal gives software makers until the end of 2018 to implement the EU-wide software update but, last week, Stuttgart administrative court told the southwestern city government that this would not be enough to meet its clean-air obligations, making diesel bans likely there from next January. Court cases in other cities are pending.

“I’m curious how nine million German diesel drivers react when they realise they’ve been had,” said Jürgen Resch, head of the DUH environmental group behind air quality court cases in 14 cities.

On Thursday, environmental and consumer groups were still puzzling over the terms of the deal, in particular Daimler boss Dieter Zetsche’s remark that the fixes would have “no effect” on fuel use or performance.

The agreement notes that carmakers “confirmed explicitly” that new cars designed to the newest “Euro-6” standard will have an “optimal” filter function in all on-road situations, in particular their use of urea mixture to eliminate nitrogen dioxide.

Consumer groups saw this as a tacit acknowledgement that this was not the case in the past, with nitrogen oxide (NOx) filtering reduced on the road and in lower temperatures.

Germany’s federal consumer association head Klaus Müller said the agreement was a disappointment, offering no clarity on compensation before, or guarantees after, software updates.

“We need independent, on-street testing of cars and an option for model lawsuits for consumers to bundle their claims,” he said.

The ADAC car association, which has warned its members to hold off on buying a Euro-6 model until successor models go on sale in the autumn, said “failures of the manufacturers cannot come at the expense of millions of diesel owners in Germany”.

Media reaction

The media reaction to Wednesday’s meeting was largely negative, with many outlets criticising as arrogant the press conference performance of Mr Müller. Many outlets suggested the summit agreement demonstrated the unbroken political influence in Germany of an industry one daily newspaper dubbed the “axles of evil”.

“Car companies have become Germany’s bogeyman,” noted the Handelsblatt business daily, “and they only have themselves to blame.”

Prof Claudia Kemfert, energy analyst at Berlin’s DIW economic institute, said: “You could say we are governed by the industry.”

One of the few voices defending the car industry, and warning against “demonising diesel”, was the far-right Alternative für Deutschland (AfD).

The opposition Left Party described the deal as a missed opportunity, with the software updates a “placebo” to get the government past the election. Green Party co-leader Cem Özdemir warned that “a few mouse clicks” would neither improve city air quality nor convince courts mulling over diesel bans.

After Wednesday’s meeting, Mr Özdemir said Germany’s car industry was one step closer to following Finland’s Nokia, after the arrival of the smartphone.

“I don’t want to visit German cars one day in a museum, I want that we keep producing cars in Germany in the future,” he said. “It’s clear in the long run this can only be emission-free. Others are doing this, we can’t cut ourselves off from the rest of the world.”