Originally Posted by Poly
Really? The consumer doesn't actually care about emissions, they might care a bit about fuel economy but don't believe manufacturers figures anyway. Is it the manufacturer who has manipulated his engine to the extreme to achieve the required standard or the test/standard developer who is at fault for producing an artificial test that is easy to scam? It's difficult to believe that nobody in the standards world was not aware of the risk people were optimising engines for the official test rather than real performance. VW just took it one step further.
The EPA rules state-side as I understand them are 8 times stricter than equivalent EU emissions tests. Volkswagen wanted to sell their 'clean' diesel TDI technology to US consumers interested in saving money by improving economy over traditional gasoline or hybrid cars. The trouble with diesel is you pay a premium for the car, and the saving comes a number of years down the line depending on overall mileage.
Volkswagen could give customers cars that had great economy, performance and engine durability, but not all the same time, and because they couldn't stay within strict EPA emissions, they installed the code. The TDI engines could achieve the emissions test, but it compromised durability, performance, and economy, as the engines had to run hotter.
The worrying thing is it took a clean air group and a team from West Virginia University to conduct their own tests to reveal this.
From 2017 the emissions and fuel efficiency figures for new cars will have to include real world driving, so expect the fuel efficiency to drop like a stone.