Many diesel cars sold in Portugal between 2006 and 2014 will fail to meet emission standards set by European partner countries and will not be allowed entry to Eruope's road network.
Currently, only 11 European cities, including Madrid and Paris, have promised to ban the entry of older diesel vehicles as early as 2025 at which date only up-to-date, post 2014 models, will be allowed to be driven.
'Full country' bans are part of the plan to reduce Europe's CO2 emissions. For Portugal, this means that almost 1.5 million diesel vehicles sold between 2006 and 2014 may only be driven in Portugal and will lose whatever value hey might have retained.
Expensive alterations to diesel engines are an option that will allow such cars to be driven on European roads for a few more years but owners suspect this relief will be short-lived.
An emergency meeting in Germany saw the government and major car manufacturers, including BMW, Mercedes, Opel and VW, agreeing to change software for 5.3 million German diesel cars to reduce emissions by 25% to 30%, in a €500 million project.
Sales of diesel cars are falling across Europe, a decline that is set to increase with 29% of Germans, for example, planning to switch from diesel as legislation bites
In Portugal, the market share held by diesel cars also has been slowing in a country that has a high percentage of diesel powered cars on its roads.
The new emissions control agreement may require 25% of passenger cars to be taken off the road.
Portugal’s government remains quiet over the problem and trade sources appear up-beat.
Carlos Barbosa, the president of the Automóvel Club de Portugal, commented that “diesel cars are not going to disappear any time soon, it's only the dreamers who think that way, we're going to have combustion engines for a long time, manufacturers are making engines smaller and cleaner."
Alexandre Ferreira, president of ANECRA, which represents dealers, admits there is some discussion going on among his members but the overall feeling is one of mild annoyance, rather than panic - essential when there is diesel stock left to sell.
In Portugal, the percentage of diesel cars for sale at Standvirtual, one of the largest sales platforms, increased slightly from 69% to 73% between the first half of 2015 and June 2017, says Miguel Lucas, director general of business.
But Lucas admits the scenario may change, "If governments go ahead with diesel restrictions, we are going to see a drop in prices for diesel cars because there will be a lot of supply, but this should not happen overnight."
In Germany, the flight from diesel already has begun with 77% of second-hand dealers already lowering prices.
In Portugal, the Ministry of Finance has not answered trade enquiries on incentives for changing from diesel cars and the government answers questions about emissions legislation with the standard riposte that, "issues relating to the State Budget will be answered when it is presented."
This leaves room for rumour and suspicion with consumers likely to turn away from diesel cars in preference for petrol engines, hybrids and electric vehicles.
See also: 'Two years on from 'dieselgate', Volkswagen launches diesel scrappage scheme'