disneysw, very interesting your information, if you are sure that it is true. I honestly never knew that the garmin gps had temperature sensors inside. Anyway is information to be considered. Soon when I installed the 3490 firmware on my 3790 I noticed a great inaccuracy, much below any other model I tested, but this does months, in a period in which virtually no used it ( I preferred the 1390 for ease of visualization of traffic). There is little more than a month I started to using it daily and noticed that the accuracy is greatly improved, reaching sometimes values very acceptable of 5-6 meters in more favorable conditions. Anyway, the comparative test I did recently with a 2595, both side by side, the 3790 modified lost heavily in terms of precision, since 2595 showed an average accuracy of 3 meters and 3790 mod of 9-11 meters in the open, leading me to conclude that their efficiency is actually lower. The question is how the 3790 original would behave , has I not yet had the time or guts to return to the original firmware to check. I even considered what could be any, or some, files originating from 3790 that were hampering precise tuning and even differences between the drivers, since both have different chipsets. In the next days I will do more comparative tests with users who have 3790 in my country, maybe can arrive at some conclusion.