Joanne's Alice Springs to Barrow Creek timeline is incorrect - the Kombi was too slow
There was a rumour that Joanne and Peter could not have driven from Alice Springs to Barrow Creek within the timeline provided, that their Kombi would have had to travel at 176 Km/h. Source: http://catonine.virtue.nu/theories/peterfalconio.html
NB: This rumour was actually an argument that the defence put forward in the trial.
1973, Series 2 Kombi van
According to the owners manual the top or cruising speed of the 1973 Manual Kombi is 125 Km/h per hour. It must have been in reasonable shape as the Kombi had already been driven half way around Australia and the Kombi seemed to be running fine. But there was a report that a mechanic in Alice Springs said the Kombi was running on 3 cylinders, perhaps that could be a reason why it would sometimes backfire. Apparently the mechanic fixed the problem. Considering the age and condition of the Kombi its reasonable to assume that it could manage a top speed of at least 100 Km/h, but there were reports of Joanne saying it was usually driven at 80 or 90 Km/h. So for the purpose of the exercise lets assume the Kombi was driven at 85 Km/h.
There are 3 points of reference
1. The point of departure: Alice Springs
2. The Fuel and rest stop: Ti Tree
3. The crime scene, 11 Km's north of Barrow Creek.
(The reported sighting and stop off at Aileron has not been included as the story is conflictive, I may include it later once I confirm some details)
1. The distance by road between Alice Springs and Barrow Creek is exactly 297 Km/h - google maps.
2. The approximate time of departure was 4.00-4.30 pm
3. The exact time and place of refuelling was 6.21 pm (receipt for fuel was time stamped-see evidence section)
4. The estimated time elapsed at the rest/fuel stop is 30 mins (20 mins watching the sunset before refuelling, and 10 mins to refuel and pay)
5. The approximate time of arrival at the crime scene 8 pm
6. The estimated average speed of the Kombi - 85 Km/h
1. Total distance divided by average speed of the Kombi (85Km/h) = 3 hours, 30 mins
2. Then the time spent at the fuel/ rest stop (30 mins) must be added
This now makes the expected elapsed time between departure and destination to be 4 hours.
Add this time to the approximate time of departure (4.15pm) and the calculation proves the estimated time of arrival at the destination is 8.15 pm.
This proves it was entirely possible for Joanne and Peter to drive to Barrow Creek within the time frame given.
1973 series 2 Kombi van - owners manual (Mentions cruising speed of 78 Mp/h) http://www.thesamba.com/vw/archives/manuals/73bus/1973_Bus_Owners_Manual.pdf
Kombiclub Thread: (Discussing top speeds of Kombi vans) http://forums.kombiclub.com/showthread.php?t=30004
Distance by road, from Alice Springs to Barrow Creek http://g.co/maps/v6372
Personal Opinion: There seems to be no truth in this rumour