I wanted to get an idea of energy usage involved in towing Custard – a 14′ Wanderer sailing dinghy – so I could work out our range when towing the dinghy.

A Better Route Planner provides an easy way to work out how to get somewhere with charging stops along the way. You can also tweak your car’s energy usage. Their base figure is nominal usage at 65mph.

Custard’s trailer has higher drag that I would expect – in my Mazda 6 it looks like petrol consumption goes up by 25%. This doesn’t appear great for something that is fairly aerodynamic (boat shaped) and not particularly heavy (I guess around 340kg). When I used to tow a Jaguar 21 – 1100kg plus trailer – it seemed to double petrol consumption so for something much smaller 25% seems high.

Anyway, first guess was that the energy consumption in the Tesla would go up by 25 – 33%. The nominal energy consumption per mile is around 255Wh/mile at 65mph according to A Better Route Planner. This seems close to what we get on a normal local journey. So this would mean consumption of around 320 – 340 Wh/mile.

The best way to mount 8″ trailer tyres is to take them to a tyre fitter. This method is how I did it and I’m noting it for future reference. However a lot of swearing is involved.

First look at the wheels and tyres. The ones I did years ago went on fairly easily. These laughed at me – no way were they going on.

I discovered what happens if you fit an outboard (Torqeedo electric) and the rudder isn’t firmly forwards.