proven technology
needs and criteria of a B + heavy duty engine market
fuel economy
cost versus benefit prediction
integration possibilities in industry fabrication standards
reduced emissions
The RLE is expected to be less effected by the EGR wear mechanism. Also, 2007 emission levels will require expensive after-treatment devices. While the modern lubricant additive package for diesels has extended the engine life, the same additives also poison the after-treatment devices. It is expected that the RLE will tolerate much lower levels of anti-wear additives.

Finally, efforts to reduce CO2 emissions are compatible with the potential threat of global warming.