So, Volkswagen thing.

[richardf8]

For those who may not know, VW is having a scandal because the software controlling the TDI engine was written to note when it was being emissions tested, and operate the engine in a way that it would pass, but under normal operating conditions, it was out of compliance, emitting 40x more of some pollutants than permitted

Comments

[james_b]

The new Euro 6 regulations set different standards for petrol and diesel cars. For diesel cars, they dramatically drop the permitted level of NOx emitted down to a maximum of 80mg/km compared to the 180mg/km level that was required for cars to meet the previous Euro 5 emissions standards.

The limit for NOx from petrol cars remains at 60mg/km, the same as for the Euro 5 standard.

Where VW is in trouble is that their NOx figures in real world conditions (as opposed to the "Testing" conditions that the software was designed to fool) are at least an order of magnitude worse than the figures they were required to meet. Yes, the software trick lets them meet the figures, but at the cost of both power and economy. We're not talking about a small change here. We're talking about enough change in the vehicle's performance to destroy its driveability and create a serious increase in fuel consumption.

Even VW's latest diesel models that have DEF (Diesel Exhaust Fluid AKA AdBlue) injection have software that drops back the amount of DEF injected when the vehicle is not in a test cycle. The end result is that the DEF equipped VWs are only half as polluting as the non-DEF models, but still way outside the legal levels.

Retrofitting older VWs with the DEF system will be expensive (in some new models, VW had to totally re-engineer the rear suspension to provide room for the 5 gallon DEF tank), and there's an extra gauge needed to monitor the DEF tank levels. Figures of $2500 + labor per vehicle have been mentioned. For older VWs, a buy back of each vehicle at market value would cost less than retrofitting the DEF system.