The UMass Supermileage Vehicle (SMV), a streamlined, three-wheel car with a featherweight aluminum frame and a plastic shrink-wrap shell, rolled smoothly through the Society of Automotive Engineers Supermileage® competition in Marshall, Michigan, while getting a tightfisted 1,010 mpg and finishing in fourth place out of 28 colleges. “We ended up rebuilding, significantly improving, and competing in the car we drove last year,” says faculty advisor Jonathan Rothstein of the Mechanical and Industrial Engineering Department. “The main upgrade was rebuilding last year’s engine from the ground up.” During the competition, not only was the UMass SMV a model of efficiency, but the UMass SMV team was a model of sportsmanship.
Getting the car ready for Marshall was a year-long project. After last year’s SMV competition, the UMass car was already aerodynamically sound, resembling a torpedo with wheels. The aluminum frame had fiberglass rods forming the contour of the body, almost like the ribs of a model airplane fuselage. Then team members fitted shrink wrap around the rods and heated the plastic to make it snug and tight.
But inside this sleek body, the team needed to add a lean, mean, fuel-stingy engine before going to Marshall.
“So over the course of the past two semesters we re-sleeved the whole engine,” explains Rothstein. “I had students who spent pretty much the whole year just putting bearings everywhere they could go in the engine. We increased the compression ratio on the engine to about 12 to one. That engine, when we tested it, was almost 40 percent more efficient than last year.”
The team also built two additional engines in case of breakdowns. “We try to bring backups for everything,” Rothstein says. “One of the unwritten rules of the competition is that, if you don’t have a backup for anything, it will break.”
The unwritten rule turned into the writing on the wall shortly after the UMass team’s first successful run on the Marshall track this year, when it got about 850 mpg. The UMass team was working on its car in “Pit Row” – the line of canopies set up by all the colleges to protect them from the weather – when the members from another team came up and said they just blew their starter motor and didn’t have a spare.
“So we leant them one,” says Rothstein. “That’s the way it is there. It’s not at all a cutthroat competition, it’s very friendly and collegial. People there are honestly hoping everybody does well.”
As fate would have it, during the next run for the UMass team, the chain broke on its own vehicle. “That’s when we all looked at each other and realized the only thing we didn’t bring was an extra chain,” says Rothstein. “One of our guys went running around Pit Row and found a team that leant us a chain in the size we needed.”
That’s also when it became obvious that good supermileage karma, driven by good sportsmanship, managed to steer around the competition’s unwritten dogma about bringing spare parts.
On the following run after fixing its chain, the UMass team came tantalizingly close to the magic 1,000 mpg mark, getting 991 mpg. “That’s always been my dream for the UMass team!” exclaims Rothstein.
So the 12 team members went to work tuning their engine more aggressively, realigning the wheels, and fine-adjusting as many moving parts as possible. But all that fine-tuning also demanded some fine-tuning by the UMass driver.
“After all the adjustments we did, our driver had to change her approach to match the performance of the car,” explained Rothstein. “She had to optimize her performance on the fourth run.”
Here’s why. In the past, UMass SMV teams have helped to develop a fuel-saving driving protocol based on accelerating to about 25 mph and then coasting back to 10 mph before reaccelerating. This method results in huge boosts for the mpg.
“But now this vehicle was coasting so well that our driver didn’t have to accelerate so quickly or reach such a high speed before going into a coast,” said Rothstein. “What she realized after a couple of runs is that she was doing three full burns per lap. But after she made more efficient use of her coasting, she was able to get that down to maybe two full burns per lap.”
The result of this marriage between mechanical fine-tuning and superior human performance was breaking the vaunted 1,000 mpg barrier. Next trip around the course, the UMass SMV glided, coasted, and cruised to a cool 1,010 mpg.
But even after a successful day at the track, the work wasn’t over for the 12 UMass team members. Several of them went to other teams and gave them a helping hand. For example, one college had only three members on its team, and they couldn’t get their engine started.
“Well,” says Rothstein, “one of our guys went over there, did some troubleshooting, and got their car up and running in 15 minutes. That’s the spirit of the competition!”
The SMV team would like to express special thanks to its key underwriter L3-KEO and other generous donors. (July 2013)