2009 Volkswagen Jetta TDI Long Term Update 5

"At around a quarter tank or so, the gas gauge becomes wildly inaccurate if there's any topography involved," says associate Web editor Kirill Ougarov.

"Heading back to Malibu over the weekend, I seemingly had roughly a quarter tank of gas left, plenty to get to where I needed to go and back. Fifteen miles or so later, the gauge is now almost on empty and the car is telling me that I'm going to be pushing it in about 20 miles, which leads to some minor panic. On the way down, the missing diesel magically reappears and the car is back up to almost a quarter tank and telling me that it's good to go another 100 miles. Of course some fluctuation is to be expected but this just seems silly."