Biodiesel - One Month Update
Its been a little over one month since I switched to biodiesel and I am happy to say I have absolutely no problems or issues whatsoever. I burned two tanks of B80 (80% biodiesel, 20% petroleum diesel) before filling thew car with it's first B100 tank about ten days ago.
During the first week there were a few really cold mornings somewhere in the 30-38 degree range where I wondered if I would have gelling issues. The 20% p-diesel probably helped me out a little. Twice the car turned over hard a few times but had no trouble starting. It's also worth pointing out that I experienced no measurable difference in the peppiness of the car when switching fuels. I did only drive it for about three days before filling it with biodiesel though so I wasn't really in tune with its subtleties. And since my last car was a four cylinder Saturn wagon I am not used to much horsepower anyway. I can say with a fair amount of certainty that you will not be disappointed in the performance of a TDI Jetta running well made B100.
Now for the bad news. Watching the gas gauge during the first full tank it seemed like my mileage was considerable less than I had anticipated. Sure enough when I filled it up the second time I calculated about 29.5 miles a gallon. Not to bad for a normal car but I was hoping to do at least ten miles per gallon better. At that point I wished I had ran a few tanks of p-diesel through it so I had something to compare to. My tires were inflated to the VW recommended 25psi. I increased that to around 40psi, just about 5 pounds less that the tires listed as the maximum. I also changed the fuel filter. Since biodiesel is such a great solvent it can clean a bunch of junk out of your gas tank and lines that then gets caught in the filter. Biodiesel people generally recommend changing it about two weeks after you make the switch.
The second tank looked to be doing much better right away. Then about halfway through family came to visit and I did a lot of city driving with a person in every seat and a truck full of stuff. The mileage was definitely shot for that tank. Miraculously when I filled it up with B100 I calculated 34.5 mpg! Much Better.
Based on fuel gauge observations it appears that I am doing much better on this current tank. All the miles should be just me doing my normal commute, I am hoping to get into the upper thirties at least. If you are buying an '05 or earlier Jetta you may want to get a manual if you hope to consistently get in the fortes. I may have underestimated the toll an automatic takes on the mileage. According to the dealership that is less true of the redesigned Jetta. I will be anxious to see if that is true of real world experience.
I am completely happy with the switch so far and have been talking the ear off anyone who will listen about how then need to switch to biodiesel ASAP.
