Found a long straight stretch (6100') the other day and was testing out the new LI HP's with my PL3 and LA. The HP's performed magnificently.
We decided to see how far away we could get a reading on the Vette with no jammers running. That was 4100'. I decided to see what would happen with only headlights on, no jammers. The range I was clocked at was 1900', less than 50% of the no headlight reading.
This was just at dusk, not scientific but interesting and seems to confirm our findings from one of our previous jammer test events.