Made trip to work from atlanta metro North I-285 South below airport (37 miles). Some road debris must have punctured a hole in thermoplastic fuel tank leading edge. Smelled fuel at work and tightened cap. Parked on hill at work with less than 1/2 tank. After lunch with a co-worker discovered fuel leaking. Vehicle towed home. No luck with GM customer service. Removed tank that week-end. After discussions with composite M&P engineer and distributor began tests on several repairs using a smaller plastic tank. Placed repair on fuel tank following week-end using aircraft sealant, 8 fiber glass plies, and final coat of epoxy resin. Conducting sloshing tests on smaller tank which only has sealant over 9 holes. No leaks at 7500 cycles. I consider GMC Jimmy tank as temporary repaired until more tests are conducted. Digital pictures available and may be emailed. Incident resulted in an unsafe condition and could have led to fatalities and casualty losses people might not have discovered since it is difficult to determine root cause after a large fuel fire. This incident although somewhat unusual happens occasionally to plastic tanks. I spoke to several people in my office aware of like situations. I am disappointed GM did not use a shield to protect the leading edge as a means to protect the tank from puncture. The fuel tank remains on the vehicle. It is expensive to replace since tank has bonded fittings and no other tanks are available. Its a design defect. No doubt mfgr may have met minimum fmcsa part 393 drop requirements yet requirement is not adequate to resist puncture loads from road debris as shown this instance. Geico ins advised it is rare but it does happen. As structural engineer involved in safety decisions I am appalled at decision not to protect tank better. A small thin steel sheet.

- Duluth, GA, USA