Of the 17,000 respondents to the survey, which was compiled by specialist law firm Slater and Gordon, 11,600 said that their car had received the new software, and 40% of those said that it had negatively affected their car.
The most common (18%) issue was a reduction in fuel economy, followed by poor running (11% claimed their car juddered), while a small portion (2%) said they suffered complete engine failures or dangerous limp mode activation while driving on the motorway.
This latter scenario was described by more than 1200 respondents, one of whom said their car slowed to 10mph while travelling in the outside lane of the motorway due to the error.
“When you stop and think about what could have happened, it’s really scary,” said one respondent. “It’s unbelievable that Volkswagen thinks it can get away with putting people’s lives at risk.”
Slater and Gordon has compiled the survey in the run-up to a group litigation hearing in which it will represent more than 40,000 affected car owners in a legal case against Volkswagen. It's thought that this will be the largest case of its type in the legal history of England and Wales.
The Volkswagen Group has hit back stating that the survey was compiled to encourage more people to "sign up to the court case". It said in an official statement that it does "not believe such surveys have been reliable or representative of the experience of owners of affected vehicles in the UK or elsewhere in Europe".
"We have made it clear that we do not anticipate that our UK customers have suffered any loss or financial detriment as a result of the NOx issue. In particular, we note that an adverse financial impact on the residual value of affected vehicles as a result of the NOx issue has not been identified."
The VW Group has rolled out its fix in over 840,000 vehicles in the UK and in over 6.4 million vehicles in Europe. It said that "the overwhelming majority of customers with these vehicles are satisfied".
The UK case follows suit of a similar one in the US, which resulted in Volkswagen paying out $14 billion (about £9.8bn) in civil and criminal sanctions. The UK case will argue that affected customers on this side of the Atlantic deserve a similar payout for their issues. Volkswagen has maintained that the US and European situations are not comparable.
The German brand has also maintained that its fix has no adverse effect on engine running, although it has also pledged to “very carefully” assess complaints from customers.
Last year, an Autocar study showed that Dieselgate ‘fix’ cars can suffer from worsened fuel economy and increased CO2 output. A report by the Volkswagen Diesel Customer Forum said that owners of models with the 2.0-litre diesel fix had also experienced breakdowns and mechanical issue last year.
Volkswagen has since said that it will “act responsibly and swiftly, in line with its goodwill policy” to respond to any “reasonable” consumer concerns. It has promised to evaluate potential issues relating to cars that have fewer than 160,000 miles on the clock and have received the fix within the past 24 months.