I tested out one of those old diesel Rabbits and ya they were slow. Later I got a Mercedes 220 diesel. It think it was the slowest car on earth. I have a thing that checks 0-60mph times, and then it tells the 1/4 mile time. It took more than 1/4 mile to get to 60 mph. It gave fairly good mileage for a big boat though, and a nice ride too. Anyway the diesel ignition improver (DII) may be a good idea. They used to use Amyl Nitrate for that, but now it is hard to find because of druggies using it. It is a heart stimulant. There are other types available. We have E 85, 85% ethanol, but you can't get it pumped into a gas can anywhere here, and it is hard to find.