Testing a baby bottle heater for UVO. Those of you running on vegi oil and who are using a baby bottle heater round your fuel filter as a pre-heater, may be interested in this little experiment I did this morning. I attached 2 temperature sensors, one (A) at the top of the filter, the other (B) tucked between the heater and the filter. The temperature in the car (parked outside) was 6C. I plugged in the heater and the (B) temp rose steadily to about 24C. (A) followed and after about 40mins was about 19C. Once the engine started, it took a while (don't think my glow plugs are working) it was remarkable how quickly the new cooler fuel reduced the temp in A and B - it fell off to about 10C. However, after about a mile, the temperature started to rise, and after 5 miles both A and B were recording 26 to 28C due to the engine heat. So, it seems to work quite well. Just not sure if the UVO has gummed up my glow plugs - they were working fine up until a few weeks ago. Only have the car a few months, so no idea of the full history. Any other tips for keeping this project on the road gratefully recieved. What does the absence of the glow plug light actually mean, as I thought if the lights stayed on after starting, that meant they needed replaced, so what if it doesn't come on at all!