proven technology
needs and criteria of a B + heavy duty engine market
fuel economy
cost versus benefit prediction
durability
integration possibilities in industry fabrication standards
reduced emissions
For industrial and commercial applications, the cost of fuel typically exceeds the initial cost of the engine by a large factor. For example, a 3% reduction in fuel consumption for a 500 hp industrial diesel operating at rated power and 8,000 hours per year represents over $7,500 in annual savings (due to much higher fuel cost in Europe, the pay off will be even faster).

The above does not include reduction in maintenance cost, mainly because it varies among applications and is very difficult to estimate. Due to the inherent interconnection between emissions, fuel economy, and maintenance, the RLE advantages will become even more significant as heavy-duty engine exhaust emission regulations continue to stiffen.