OK- The oldest pumpers right now are (3) rigs that are 6-years old. TL-71's rig is going on 10-years old, and since I work in that house, I can tell you it's beaten up- They ran a spare for 1/2 of 2008. The rig before that (Mack) ran for 15-years before being replaced, and that was too long ! The Chief was able to tack on 75's rig to order because in 2009 the new emissions will be required in the rigs, which will make the price go quite a bit more. The spare 90' Mack has seen better days, and was refurbished once already a few years ago. For many years we ran junk (ie:the Continentals) which would break down often. The Chief in charge now, who worked with all the garbage, swore it wouldn't happen again- and was able to secure funding for replacements. I remember riding in a station wagon as a spare engine numerous times a few years back, and when we had no Truck spares- so we bought a 1956 screw down jack mid-mount !