As NASCAR descends upon Autódromo Hermanos Rodríguez in Mexico City this weekend, drivers and teams face an unusual adversary: altitude.
Sitting at 7,500 feet above sea level, this road course dramatically changes the dynamics at play. The notorious Las Vegas track, by contrast, is only about 2,000 feet. The higher altitude translates to thinner air, which significantly impacts engine performance and cooling - two crucial factors in any race.
Doug Yates, president and CEO of Roush Yates Engines, points out that the thin air can cut as much as 20% of the horsepower from the 670-horsepower Cup engines. “You’ve got to fool the engine into thinking the conditions are better,” Yates explained to NBC Sports.
For a seasoned contender like Daniel Suarez, the altitude introduces a new layer of complexity. “I don’t think you have to drive different, but the cars are going to have more mechanical grip,” Suarez noted. With the expected loss of 80-100 horsepower, drivers will notice differences, especially through the high-speed corners, where downforce will also diminish, leading to adjustments in handling.
The last time the Xfinity Series raced here from 2005 to 2008, engine challenges abounded. The debut years saw multiple engine failures, although by 2008, lessons learned led to no failures over the race weekend.
Now, teams are focusing on cooling as much as on power. NASCAR has permitted teams to experiment with two types of hood louvers during practice to optimize engine cooling. Trent Owens, crew chief for AJ Allmendinger, highlighted a unique issue: “The problem we have with the engine is the caution laps. It gets so hot under the caution laps.” This heat buildup can force engines into protection mode, altering timing and fueling to prevent damage, compromising horsepower.
NASCAR's two-race engine rule adds another layer. Doug Yates reported that many Ford engines running in Mexico previously competed on the half-mile short track at Martinsville. “We shift at Martinsville every straightaway, every lap,” Yates explained, making adaptations to align with Mexico’s circuit a sensible strategy.
With all these mechanical and environmental factors in play, this weekend's race promises to test the mettle of both man and machine like never before.
