I would like to increase my fuel mileage in my 1984 300D TurboDiesel. Reviewing the past service invoices, it appears that all of the injectors are original at 253000 miles except one. One injector was leaking around the housing requiring replacement.

I recently replaced the air filter. At present the car gets ~23 mpg.

Should I expect a significant increase in fuel economy and performance by replacing the old injectors? Must I also invest in a refurbished injector pump along with the new injectors? What is the best mostly-highway-driving fuel economy that I can expect. How can I determine if the pump start timing is off by observing performance? What indicators should I be looking for?

What is the procedure to correctly change injectors? I have been told that it is not difficult, but this car is my first diesel. I have a quality break-away torque wrench. What should I avoid or be careful with in this procedure?

Finally, I hear of experimenters who are fueling their engines with biodiesel (100% processed vegetable oil.) Would some kit or special adjustments be required to accomplish biodiesel use? I understand others are doing nothing to accomodate biodiesel use.

Thank you,
Michael Smith