Cummins Inc. today announced that its Uptime Guarantee for U.S. heavy-duty on-highway truck engines has been extended for all engines placed in service through Dec. 31, 2004. The Uptime Guarantee covers Cummins ISM and ISX engines for the first 12 months of operation. With the guarantee, Cummins will reimburse the customer for truck rentals up to three days for any failure on an ISM or ISX engine that can not be repaired within 24 hours. The Cummins Uptime Guarantee was first introduced in August 2002. "The Cummins Uptime Guarantee provides assurance to trucking fleets and owner-operators of the exceptional performance and reliability of these 2004 EPA-certified and compliant Cummins engines," said Tom Kieffer, Cummins Executive Director - Marketing.