Extreme Tests Help Chevrolet Ensure Durability, Reliability
BANGKOK, THAILAND – A group of Chevrolet Trailblazer customers overcame challenging off-road terrain in Petchaburi province on a recent humanitarian mission. Before the Spirit of Trailblazer Club could cross rocky streams and traveled bumpy roads, engineers at General Motors put the SUV to even tougher durability tests during months of vehicle development.
“We can go to remote places because we’re confident our Trailblazers can handle rugged conditions,” said Dr. Phuchit Phuripanik, a leader of The Spirit of Trailblazer Club. “Not only did Trailblazer’s capability enable us to complete missions of social responsibility, it also let us have a lot of fun along the way.”
One of the most damaging elements to any vehicle is uneven and broken surfaces, especially those riddled with potholes. More than an uncomfortable nuisance, they can damage tires, wheels and suspension components and ages the vehicle prematurely.
One of the major reasons vehicles sustain damage when they hit a pothole is because load is not transferred properly. Towards this end, roads in GM’s Milford Proving Ground in the U.S. are carefully engineered, laced with manufactured potholes ranging from mildly-annoying to chassis-rattling. The intentionally poor road conditions help engineers thwart the bumps a vehicle takes and tune suspensions to minimize discomfort to passengers.
The engineered potholes help experts re-create load conditions that occur when a vehicle hits one on a non-controlled surface. GM has collected that data for the past 40 years, using it to design and engineer new vehicles to better able to absorb pothole abuse. There is a wide variety of road surfaces that simulate real-world road conditions around the globe.
These extreme durability tests go beyond potholed pavements and include terrains like construction sites and off-road environments, the latter for Chevrolet’s trucks and SUVs.
“Every Chevrolet built globally goes through this type of testing. And we design our vehicles to absorb the load when they hit a pothole,” said Mr. Chan Joo Kim, General Director of Product Engineering, GM Thailand and Southeast Asia. “The data we collect on our test course helps us to integrate loads between interconnecting parts, capture and fix potential problems as we design Chevrolets.”
While no technology will help drivers avoid every pothole, Chevrolet models share traits – such as robust body structures – that reduce vibrations generated by sudden, harsh impacts. The strong body structures also enable engineers to tune the suspensions more precisely, for smoother, more controlled driving experiences that help mitigate the effects of smaller and moderate potholes.
In addition to tough road conditions, vehicles are also put through extreme weather testing to ensure they operate normally in most conditions around the world. GM’s Climatic Wind Tunnel in Warren, Michigan can despite prevail weather outside and generate conditions that replicate anything from blizzards to hurricane conditions. Temperatures can go below -40 Celsius with wind-speeds up to 241km/h. Conversely, even on the coldest winter nights, the tunnel’s internal temperature can easily reach 60 degrees Celsius, thanks to 1,155 watts per square meter of simulated sunshine.
This facility takes vehicle development and validation testing to the extremes, subjecting powertrain cooling, cabin heating, ventilation and air conditioning systems to the harshest weather conditions. The wind tunnel also simulates driving actual roads with real-world weight burdens, such as hauling a fully loaded trailer up a steep incline by applying resistance through the wheels of the tunnel’s dynamometer, a tool that also allows simulated driving speeds of up to 250 km/h.
GM engineers subject vehicles to durability tests for up to 18 months. Given the extreme conditions, this testing simulates the vehicles’ entire lifecycle. Some testing benchmarks before the durability team will release vehicles for production include:
100,000 miles of customer use – The team drives a test vehicle more than 40,000 kilometers, though in such extreme conditions that represents 161,000 kilometers of customer use
Extreme tests – Belgian Block loop (a paving stone shaped like a truncated pyramid and laid with the largest face down), pothole drives, chatter bumps, twist ditches, speed bumps and more are driven for entire days testing various parts of the vehicle
Humidity chambers – Built in the late 1960s with new ones added in the 1980s, every car is soaked in humidity chambers. On numerous occasions cars will go in these corrosion booths for hours and endure high temperatures and humidity
Indoor testing is important because it can be done at any time of the year regardless of weather conditions, and the conditions are repeatable. It also minimizes safety risks and traffic interactions associated with testing on public roads. Still, there is nothing like getting a test vehicle out into the real world. Various tests on Chevrolet’s pre-launch models have been conducted on the roads in Southeast Asia, including Thailand.
Before the Chevrolet Cruze was launched in 2010, GM engineers from around the world hot-tested a fleet of Cruzes on the back-roads of Rayong, Thailand. To ensure the test is as grueling as possible, the engineers conducted the tests in April – the hottest month in Thailand with temperatures reaching as high as 42 degrees Celsius. By the time it was launched, Cruze has gone through a total of 1.2 million kilometers in testing on roads and tracks around the world.
The story is similar for the Colorado pickup truck prior to its global debut in Thailand in 2011. Sporting a tougher and stronger chassis than its predecessor, Colorado was developed across five continents and over 2.5 million kilometers of testing distance. Members of the development team actually lived in Thailand during the truck’s development phase, immersing themselves in the highly-competitive truck market and observing how Thais and other markets in the region use their vehicles.
Closer to launch, GM engineering teams embark on what is known as “buy-off” tests. These are tests to ensure that all systems are in working order and every function works before engineering “buys off” the vehicle for production and sales. The Captiva, now available with a “Sport Edition” variant featuring a rear view camera, LED daytime running lights, spoilers, body kits and side-steps (for gasoline variants), was put through a series of tests on the back-roads around Khao Yai National Park prior to its launch in 2011. The location was chosen for its winding roads over hilly terrain – the perfect playground to test Captiva’s superior driving dynamics, ride and handling capabilities.
“By putting our vehicles through the toughest tests in the industry we help ensure high durability and reliability for Chevrolet customers in Thailand and around the world. Their safety and satisfaction are our top priorities, and we go to extremes to deliver on that promise,” said Mr. Kim.