MPG after first full tank

[powerandtorque]

Whilst perhaps not on here, people certainly have tried SVO on a Lucas and it will fail, just a matter of when.

You'll likely get away with running a reasonable veg/diesel mix now that the weather has warmed up, but how strong and for how long is open to debate. Plenty of info and other peoples experiences out there if you search.

As above, if you're handy with a set of spanners then swapping over to a Bosch setup is the way to go - with the mileage that you're doing you're recoup the cost very quickly by being able to run SVO.