Running a Catalytic Converter and Starting Last — on Old Tires

With EcoBrap, Matt Cresci hopes to show you can minimize the carbon footprint of racing while still having fun and finishing well.

NASA NorCal Spec Miata racer Matt Cresci knows a thing or two about winning. He finished fourth in Spec Miata at the 2014 NASA Western States Championships in a car he drove to the track and then home again when the race was over. He finished second in Spec Miata at the 2015 Western States Championships, and drove his racecar home afterward, and fourth again at the Western States Championships in 2016 after finishing in the top spot in all but the Championship race.

That performance earned him an at-large invitation to the 2016 Mazda Road to 24 Shootout at NOLA Motorsports Park in New Orleans. Cresci won the Shootout and the $100,000 scholarship good toward a season of racing in the 2017 Global MX-5 Cup Series. In Global MX-5 Cup, Cresci won race one of three in the Global Challenge at Laguna Seca, which featured drivers from the United States, Europe and Japan.

This year, Cresci is racing with NASA, proving he knows a thing or two about minimizing the environmental impact of racing by seeing how long and how fast he can go on a particular set of tires with a limited amount of fuel per weekend. That’s the whole point of EcoBrap, his most recent initiative, to show that gearheads can pursue motorsports with fuel economy and a limited environmental impact in mind.

“After a recent trip to Europe in December of last year, I just kind of noticed that we’re not quite as efficient as our buddies across the Atlantic Ocean,” Cresci said. “Basically, I’ve just drastically reduced everything because I think that we go kind of overkill on some stuff, whether it’s our tow vehicles or our trailers. You go to Europe and you’d see these guys towing around open trailers with Jetta TDIs, and the guys are getting almost mid 20s, high 20s miles per gallon, and it’s just a huge difference in efficiency between over here and over there.”

Cresci set out to achieve more than 20 mpg while towing an enclosed trailer. If you’ve ever switched from an open trailer to an enclosed trailer, you know full well the difference in fuel consumption. To achieve this goal, Cresci tows with a 2016 Dodge Ram 1500 with the HFE Ecodiesel engine. He pulls a 2007 Montrose lightweight aluminum car trailer. It’s also a low-profile trailer, barely tall enough to clear the roof of the car. So far, the best mileage he’s achieved is 23.5 mpg while towing the 4,000-pound trailer.

“Basically, I’ve cut my fuel costs in half because my old truck and trailer combo used to get about 10 mpg while towing, which seems to be about average,” Cresci said. “I’m now getting 20 to 22, hand-calculated, so my fuel cost is literally cut in half, which is about $1,100 a year.”

The racecar is a Spec Miata with a metallic-core, high-flow catalytic converter band-clamped to the tailpipe of his exhaust. The good news is that the dyno showed no difference in power output with the catalytic converter in place. Unfortunately, emissions tests also showed no difference, so Cresci is going to move the converter farther forward in the exhaust system so that it gets hotter and can maybe be more effective at reducing emissions.

One ironic hurdle to his efforts is that Cresci had to involve a friend in a “straw purchase” of the converter because Summit Racing cannot ship them into California due to California Air Resource Board regulations. That’s a lot of trouble to go through to put a catalytic converter on a racecar.

“It’s not so much that it’s not efficient enough to pass CARB certification. It’s that each catalytic converter that comes into California needs to pass CARB certification, which costs money,” Cresci said. “Some manufacturers and distributors just don’t want to deal with that, and they don’t even bother trying to get it certified because there’s a lot of costs associated with it.”

Cresci hopes to use less than 15 gallons of fuel in the racecar per weekend and make one set of tires last nine races. To do that, he skips practice and qualifying, then starts the race from dead last and tries to work his way to the front. He just started racing on his second set of RRs in September.

In March at Sonoma Raceway, skipping qualifying, Cresci finished 11th out of 37 in race one, sixth of 41 in race two and fifth of 39 in race three. Not bad when you consider two of the drivers consistently finishing in front of him were Tristan Littlehale and Justin Casey, a Spec Miata national champion and a podium finisher at the Championships, respectively.

In June at Sonoma, he did not skip qualifying, and went out and won race one on tires with eight heat cycles on them. He finished second in race two on the same tires and second in race three that weekend.

The ecobrap website has a handy calculator that lets you easily calculate how much money you’d save in fuel expenses with just slight changes in the fuel economy of your vehicle.

“The tires are excellent. It’s one of the main reasons that I run NASA. It’s their affiliation with Toyo,” Cresci said. “I currently believe that the RR is the only tire available that is competitive until it literally cords. So, I would have no hesitation running these tires until they cord, but this time around, I’m going to hard-document it and see if that’s actually true.”

He documented the June Sonoma weekend on the EcoBrap YouTube channel.

At the May event at Sonoma, he had one second place in three races. In August at Thunderhill, he finished third in race two and second in race three. It helps to be quick to finish well — and Cresci obviously is — but it shows what can be done, even if you start at the back. Cresci is currently second in points for the 2019 NorCal Spec Miata regional championship.

Of course, motorsports being what it is, no one from the Sierra Club is going to give Cresci any awards for what he’s doing, but as he pointed out, everyone needs an outlet. Racing is his outlet, so he’s attempting to make it as economical as possible. Thus, the name and the goals of the program.

“After all my calculations, it seems like I’m releasing about 3 tons of carbon dioxide as a result of my racing season,” Cresci said. “Both a combination of my towing and racing is about three tons of CO2. So, I then asked myself, ‘Okay, what does everyone else my age, 26, do for fun?’ Well, they go and travel somewhere. So, I calculated the carbon footprint of one economy class seat round trip to Australia and it’s about 3.5 tons per person.

“So, my entire racing season has less of an environmental impact than one round trip flight to Australia from a CO2 perspective, which is pretty shocking,” he continued. “I had no idea that flying was that bad for the environment, and it’s also changed how I travel ever since I found out that statistic.”

Cresci rounds out his fleet with a 2003 Toyota Prius as a daily driver and a Honda Grom pit bike, which gets about 125 mpg, and he’s looking for more ways to reduce his carbon footprint.

“There’s no question that me not racing would be better for the environment, but we’ve all got to blow off some steam somehow,” he said. “And just because racing is part of my life doesn’t mean I can’t take a more efficient approach to it.”

Image courtesy of Matt Cresci


  1. This makes little sense when you consider the exceptionally small amount of gas used for racing. I’m all for a more efficient tow rig or for non car people driving a Prius or a Tesla on the street. But skipping practice and qualifying is missing a good part of the race weekend to save 10 gallons of gas. My daily gets about 32mpg, but when on track, I don’t care. Fuel management is one of the main complaints about Formula 1 and to some extent Le Mans (but at least fuel strategy can get interesting at Le Mans).

  2. Cats don’t do very much at WOT. A modern 3 way cat needs to switch back and forth from rich to lean to do its job. His car would be much better suited to a 2 way cat with an air pump, but even then it would likely be overwhelmed by the volume of exhaust at WOT. Ever smelled a modern car with a reeking exhaust going uphill? That’s a cat being overwhelmed by the WOT fueling and sheer volume of exhaust at a higher throttle angle. We’ll see soon enough when he hits the sniffer again with the cat farther forward. The spun metallic cats don’t do as good a job as the factory cat at reducing emissions either, they have a lower cell count and a lot less of the expensive precious materials that make a cat do its job.

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