It's ironic that one of the best characteristics of modern diesels is also their downfall, for many owners.

New diesels are so refined, and some owners so unused to filling with diesel, that they accidentally fill their cars with gasoline--resulting in a breakdown.

To help prevent this, Volkswagen is set to retrofit more than a quarter million 2009-2012 diesel cars in North America with a device to prevent improper fueling.

Failing fuel pumps

According to Automotive News, the measures to prevent misfueling have been instigated following complaints from owners submitted to the NHTSA over failed fuel pumps.

The Administration has received 160 complaints and field reports since 2011, stemming from cars stalling, often at highway speeds. Volkswagen has told investigators that 90 percent of affected vehicles had "substantial amounts" of gasoline in their tanks.

Fueling a Volkswagen TDI with gasoline voids its warranty--meaning any repairs lay at the feet of customers.

VW's fix will attach a misfueling guard and fuel filler neck cap to the affected vehicles. Should a driver insert a gasoline nozzle by mistake, the fuel tank gate will remain closed.

Investigation, not recall

The plans were announced in a dealer notice, and include 209,500 U.S. cars and 51,600 vehicles in Canada.

Volkswagen will begin notifying customers on May 28. The investigation has not yet been turned into an official recall.

Have you ever misfueled? Leave your thoughts in the comments section below.


Follow GreenCarReports on Facebook, Twitter and Google+