Diesel additive, 2-stroke oil?

Mine still is only managing 25mpg even with the 2-stroke. Although think it was about 23 before hand.


Really must fix the warped exhaust manifold as pretty sure it was before that started blowing I was getting consistent 30-32mpg

Av mpg is now 30 and it pulls like a train.
First time for 6 week driving it for me and it pulled up the 2 mile hill to home between 30 - 35mph in 4th and it could never do that before.
I got the same success 2 days later when I went to do a 2nd test run to check I was not dreaming.

Still on 250ml per tank full.