Thanks, the route is one of two both based on the recommended route. I had to add Miles in the South to make up for miles lost in the North, as seems little point in me heading North for mileage from where I am to then head South IMO. The other route uses M74 for outward and homeward legs, needs one more stop though.
Happy to learn about the needed average, I just divided the miles by the hours, no subtlety but not sure how to get it more accurate/realistic.
Your not heading north for the mileage it's what works in the 24 hour period and making the most of it.
Mileage is the number one thing to get right ... 1510 - 1515 is the sweet spot
Your looking at doing 1521 + so you've just added 10 mins which you can't afford unless you have a large fuel tank.
Heading down the A1 is a great route but you've added miles, lost time then had it removed by verification unless you do a short stop at Berwick upon tweed..
On the way down you only have one non dual carriageway which you will be doing early in the morning so avoiding traffic.
The run home is all motorway to Perth.
To do a quick cal you should allow for each stop to be 10 mins ... Some are 6 mins others can be 15
9 stops you've lost 1 1/2 hours
Finish .. could still take 10 mins and more in the wrong Service station.
so take off 1 3/4 hours off your 24 hours ... That's now your travel time.
Mileage into your time will give you your avg speed required ...
This leads to planning your fuel stops to the max your tank can do ... this gives you back 10 mins on the long stretches.
(Don't forget to carry a 10 Lt fuel can for the just in case ...
One other factor is your starting from Scotland ... This puts you into traffic at the wrong times.
The plus factor .. Yes it's Sunday so should be better.
If after 22 hours you just can't see yourself hitting the BBG then plan B Fuel at servo and claim you hard earned SS1000. ...
Hope this helps