Case Study: VW Beetle 76 mpg

| Last Updated: July 14, 2020

Hi, I thought this story should be of interest to you. I did drive 55 (52 to 53 true speed) to set this mileage record. I don't recall passing anyone on the entire trip.

Ernie Rogers

Over the Labor Day weekend, the TDI Club had it's annual get-together called "TDI Fest." The club has a large percentage of car efficiency enthusiasts that have chosen diesel technology instead of hybrids. TDI (short for "Turbocharged Direct Injection" is Volkswagen's label for it's highly-efficient automobile diesel engines. 150 people showed up for the three-day affair near Madison, Wisconsin. They were a small segment of the approximately 35,000 club members that have registered at The meeting was about efficiency and also about high performance. With a TDI-powered car, you can definitely have both.

Attendees drove to the meeting from all over the U.S. and Canada to show off their beloved fuel-sipping cars. Cars were entered in a variety of competitions from road rallying to extreme fuel economy.

The fuel economy prize was won by Ernie Rogers from Pleasant Grove, Utah. His winning car is a 2003 VW Beetle TDI. He drove 1375 miles to get to the meeting using just 18 gallons of fuel-- 1200 miles of which was accomplished on just one tankfull (15.5 gallons). His trip fuel economy was 76 miles per gallon.

Rogers' car included several small refinements that added up to the exceptional mileage: a drag reducing device he designed and built himself (pictures at, lower-rolling-resistance tires, low-friction engine oil, and use of a B5 biodiesel blend fuel to increase efficiency and improve emissions.

The hottest topic of conversation at the meeting, and the subject of a popular technical session, was on the benefits of using biodiesel or biodiesel-blend fuels. Most of the attendees were either already using biodiesel or had decided to start. It was noted that research in Canada had shown that a fuel blend with only 1% biodiesel can increase a car's fuel economy by as much as 14% while substantially lowering emissions.

Biodiesel is one of many new sulfur-free diesel engine fuels now entering the market in small quantities. Most of the new fuels (including biodiesel) are not made from petroleum, but from a number of renewable sources. Biodiesel can be made from soybean oil, canola oil, or other seed oils, and from many oily wastes such as animal fats. Low-grade oils and fats that are not fit for use in foods have now found a new usefulness. In the future, we will be able to make renewable diesel fuels from other wastes such as garbage and leftovers from harvesting of many crops including wood.

Diesel engines provide exceptionally high torque at low rpm, as well as 43% peak efficiency, higher than any other type of engine. While diesels gained a bad reputation in the past for high emissions, newly developed engines have overcome the problem, running clean on fuels with very low sulfur content.

Diesel engines naturally emit less carbon dioxide (a greenhouse gas) because of their higher efficiency.

For more in-depth information on TDI cars and TDI Fest, go to Warning: If you were thinking of buying a TDI car, expect disappointment. These cars have become very scarce because of high fuel prices.

Thanks Ernie!

An ex-salesman of industrial equipment, Shawn used to drive nearly 60K miles a year just commuting to clients. He also has a little project Miata build going on the side. Safe to say, Shawn has slain a few tires in his days. He knows all about horrid road-noise, hydroplaning risks, and how much damage a bad alignment can do to your wallet. He enjoys helping us out and Chris always values his opinion when designing something new for the website.

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