A road trip to Vegas lets us compare the mileage of our gas sipping 1.6-liter MINI with our new long term 2009 Volkswagen Jetta TDI. How does the turbo diesel stand up in a fuel efficiency over the long haul?

Last weekend my niece celebrated her first birthday. This meant another trip from Orange County to Las Vegas. I probably do this drive ten times a year if not more. Between holidays, press trips, SEMA and just random trips, I have grown to know this route with much too much familiarity.

Lately I have been making the drive in our long term MINI Cooper S. It is a great road trip car for my wife and I. Comfortable, fun and averages about 34 miles per gallon on the open road. The little 1.6-liter turbo four is a real gas sipper, which is nice since the drive is roughly 290 miles door to door. Once we get to Vegas, it works if we plan on taking another couple out for dinner and a movie, but it can be kind of tight.

This time we drove our brand new Long Term Jetta TDI. We wanted to see what the turbo diesel could do on a road trip, especially considering the extra size and weight of the sedan compared to the MINI. The drive was just as comfortable in the Jetta. We had more space than we really needed in the Jetta with everything taking up roughly two-thirds fot the trunk and the entire back seat empty. With the MINI, we tend to fill up the trunk and a good part of the backseat. But what about the mileage, that’s what everyone wants to know right? Well, the day before the drive to Vegas, I filled the car up at a cheap gas station in Glendora right before a photo shoot. I know better than to buy to cheap gas, but I was already late for the shoot and didn’t have much of a choice. Diesel was 3.09 a gallon, which turned out to be even cheaper than regular unleaded.

Even with said crappy diesel the Jetta managed to eek out 38mpg on the trip to Vegas. That is a pretty impressive number, but not quite what I expected out of the car. We left on a little under a full tank, and we were able to drive to Vegas, around Vegas all weekend on that gas. The morning we left, we filled up at a name brand station. Diesel was another 70 cents a gallon but it turned out to be worth it. On the way back we achieved just over 44mpg. That’s more like it!