Webasto Thermosystems says its Thermo Top fuel operated heater, popular in Europe, will debut as a factory installed option on an unnamed U.S. vehicle in 2004.

Thermo Top is an engine independent, auxiliary coolant heater that burns diesel or gas fuel in a closed combustion chamber, providing 17,200 Btu/h (5 kW) of heating energy to a vehicle's coolant system. It is designed for either supplemental heat, boosting heating performance when the engine is on, or pre-heating the vehicle's interior and engine while the engine is off. “No more scraping windows, no more cold interior and no more cold start emissions,” says a spokesman.

Webasto sells about 600,000 annually in Europe and the retake rate is 90%. About 80% are for the supplemental system because of the popularity of diesels, which operate so efficiently that there often isn't enough heat generated to meet the expectations of some customers. “With Thermo Top, you don't have to wait 30 minutes for the diesel to get warm,” says a Webasto spokeswoman. “Within 90 seconds, you're already getting warm.”