Hi David,

To allow for a range of atmospheric conditions and varying levels of startup gas flow, different plugs, exposure of element, etc. often some users may require glow driver voltages on the higher side. Personally, with the valve I use, start gas type, and my usual atmospheric conditions, I typically run my A3's in the range of 1.6 - 1.7V. I may boost that to 1.8 (rarely) if it starts to miss the odd ignition or two.

Sorry to hear about your plugs, normally that's not the case as they should survive short bursts at increased voltages. Also, something may have been overlooked as I believe the default setting is 180, and that should prove reliable in most circumstances... Clearly a glow plug should last longer if less voltage is applied to them. For that reason I usually recommend that new customers immediately start decreasing the voltages on their glow driver in the first few starts, until they start to recognize a lower ignition repeatability from start to start. Going up one or two tenths from that point is probably the optimum setup. It only takes a few starts to find the ideal voltage, and it sounds like you're on the right path. If 1.5 ever misses, give 1.6 or 1.7 a try.

One final note, trying to evenly stress each coil of the plug when exposing the element should also extend the life, although I haven't got any data to back that up...

Good luck with the engine.
Kelly