Volkswagen of America has announced the successful completion of its Renewable Diesel Evaluation Program in collaboration with renewable fuel companies Solazyme Inc. and Amyris Inc.
Beginning in 2012, Volkswagen measured the environmental impacts from the use of pre-commercial renewable diesel formulas with TDI Clean Diesel technology found in the 2012 Passat TDI (which uses a NOx storage system) and 2012 Jetta TDI (SCR system). The company says initial analysis found that advanced renewable fuels in the test offered comparable performance to standard crude-based diesel fuel blends while producing less CO2 emissions on average.
During the two-year evaluation, Solazyme's now-commercial Soladiesel RD (100% algae-derived renewable diesel fuel) and Amyris' plant-sugar-derived renewable diesel formula were used for the program, with each company testing a 2012 Passat TDI and Jetta TDI models. Both fuel producers added additives, which are commonly used today, to meet ASTM D 975 specifications.
Volkswagen says that its engineers found that with more than 134,000 miles logged collectively in real-world, on-road and on-highway conditions, vehicles in the evaluation offered similar performance to existing TDI powertrains operating on today's crude-based clean diesel fuels. Results from the evaluation also found that driving dynamics were not negatively impacted with the renewable fuels, while fuel economy was similar or improved.
During the evaluation period, no engine errors were triggered as a result of the fuel and no extreme wear or failures were reported that would prevent any of the vehicles tested from being operated normally while powered with the respective renewable formulas. Additionally, engineers found that during the evaluation period, there were no negative effects in the burning of the renewable fuels, while the production of soot was lower than when using conventional diesel.
Volkswagen says these key indicators highlight the market potential that renewable fuel solutions offer. Furthermore, both fuel producers claim that greenhouse gas emissions could be reduced by more than 50% on a well-to-wheel basis when using renewable fuels as compared to today's commercially available crude-based fuels.
Ewald Goessmann, executive director of Volkswagen Group of America's electronics research laboratory, states, ‘Evaluations like this are part of Volkswagen's broader holistic environmental strategy, which underscores the company's commitment to the environment by deploying a comprehensive approach which addresses carbon reduction and sustainability at each part of the vehicle lifecycle.’