Well, I’ve already done my first “mod” on my Jetta. Took me all of about 10 minutes to do. My kind of mod. What I did was called a Ventectomy. What it does is increase your fuel tank by about 2 gallons, or, with my car, adds an additional 100 miles to your tank. From the link above, you can see that you remove the venting mechanism of the gas tank. Normally, in a gas car, when you fill up, this venting area is used because of the expansion and volitility of gas. What this extra 2 gallon area does, is prevent your gas cap from blowing off during driving or while it’s sitting in the sun. However, diesel doesn’t exhibit these features, so that extra 2 gallon tank goes to waste.
In all actuallity, I didn’t have to remove the pieces, you can just press the button back as you fill up (preferably with the nozzle, because diesel is dirty). However, this just makes it way easier. Instead of having the little nub sticking out into the fuel line, there’s what looks like just another tube.
With this mod, my tank will hold the same, if not a little more than my truck used to. Ought to be interesting to be comparing them directly on tank size. When I didn’t go on the freeways at all, I was lucky to get 300 miles to a tank with the truck. I should easily be able to double that now.
Speaking of gas mileage, the car has been awesome. I’ve been averaging around 44mpg. However, this last fillup, I didn’t do such a great job. I only got 38mpg, my lowest yet. This could be due to almost total city driving though. No matter what, though, it’s way better than my truck was in about every single way.