hi there friends from across the "pond".... i have an econoline 350 van 7.3 ltr diesel 1989... it has twin tanks... and she loves veggie oil ( straight)... it's a bit hard to start in the cold but once she's warm she loves it. In the winter i use 100% diesel in one tank .. for starting and stopping and 20-50% veggie oil in the other tank for when the engine has warmed up !.. in the summer it's 100% veggie all the way !!.. i get 18.5 mpg on diesel ( on a run ) and 22mpg on the veggie ( on a run ) .. only started using it last year.. when the price of diesel topped £1.40 ( that's a ltr.. not a gallon )!!!... so far done about 6000 miles.. with no problems !!.. when i started veggie oil was 0.85 a ltr.. the shops soon grew aware of what people were using it for and the price soon went up to £1.15 a ltr !!... with diesel at the pumps now at £0.99 a ltr. i have gone back to the pumps....