1989 Extended Cab, 4x4 Tahoe, Sun Roof on 2040-cars

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'Killing a Duramax' Gale Banks YouTube series methodically tunes a diesel to death

Learning or perfecting a skill by watching YouTube videos is known as attending YouTube University. GM Authority picked up on one of the video site's more fascinating courses, hosted by Gale Banks; in a fair world, he should be referred to as Professor Banks when it comes to diesel engines and truck tuning. A few months after GM introduced the updated L5P 6.6-liter Duramax diesel V8 in the 2020 Chevrolet Silverado HD and GMC Sierra HD that ships with 454 horsepower and 910 pound-feet of torque, Banks decided he wanted to methodically tune the engine to death. The purpose of the resulting series, called "Killing a Duramax," is to push more power out of the engine in order to discover which parts break and when — or, as Banks puts it, force-feed the Duramax "until the crank hits the street and the heads hit the hood." With that knowledge, Banks can figure out all the weak points on his way to building what he calls a "Superturbo," that being a supercharged, twin-turbo race engine with more than 1,000 hp. What makes the series fascinating is Banks' knowledge, paired with the company's comprehensive iDash engine monitoring system that keeps tabs on a glut of parameters every step of the way. So for instance, you get Banks explaining the differences between inches of mercury and barometric pressure, how those are different from the water content of the air measured in grains, then showing those readouts on the iDash, then explaining in detail how they affect the air density in the Duramax system. The stock Borg-Warner variable turbo gets a lot of airtime — Banks accuses it of being "out to lunch" because he feels it's the weakest link on the engine. That turns into a turbo teardown and a deep explanation of performance pitfalls, such as when air pressure on the turbine begins to diverge from the boost pressure coming from the compressor. Banks says he can keep close tabs on where power's coming from, because the iDash monitors the horsepower contribution provided by the ambient air, the turbo, and the intercooler separately. The major changes so far are a stouter Precision 7675 turbo and TurboSmart wastegate (episode 5), a twin intake (episode 6), a custom liquid-cooled intercooler from a marine engine, a new GM oil cooler and synthetic oil (episode 10), and new injectors (episode 11).

Smaller Cars Endure Big Problems On Crash Test

In a crash test of 11 of the smallest cars on the market, only one vehicle received an acceptable rating. The rest received marginal or poor ratings in the study, providing evidence that supports a widely held notion that smaller cars are among the least safe on the road. No other vehicle group has performed as poorly on a new crash test than these mini cars, says the Insurance Institute for Highway Safety, the nonprofit group that conducted the testing. The latest results of which were released Wednesday. The Chevrolet Spark was the only car earning an overall "acceptable" rating on the small-front overlap test, and even that vehicle had its shortcomings, IIHS said. "Small lightweight vehicles have an inherent safety disadvantage," said Joe Nolan, the senior vice president for vehicle research at IIHS. "That's why it's even more important to choose one with the best occupant protection. Unfortunately, as a group, minicars aren't performing as well as other vehicle categories." The Mazda2, Kia Rio, Toyota Yaris and certain Ford Fiesta models all received "marginal" overall grades on the test, while the Mitsubishi Mirage, Nissan Versa, Toyota Prius C, Hyundai Accent, Fiat 500 and Honda Fit all earned "poor" ratings. Results from these sub-compact cars fare much worse than vehicles sized just a little bit bigger, IIHS said. Among 17 cars evaluated in the small category, five earned "good" ratings and five more earned "acceptable." Only introduced a year ago, the small-front overlap test has quickly become a key indicator of differences in automotive safety. IIHS introduced it as a way to replicate what happens when the front corner of a vehicle collides with a tree or utility pole at 40 miles per hour. In the real world, these sorts of accidents are more dangerous than others, in part because they bypass the front-end crush zones on most cars. TOP 5Most Researched Sedans 2013 Honda Accord MSRP : $21,680 2013 Hyundai Sonata MSRP : $20,895 2013 Nissan Altima MSRP : $21,760 2014 Honda Accord MSRP : $21,955 2013 Toyota Corolla MSRP : $16,230 Automakers have been rushing to make design changes to the front ends of their cars. Without a grade of acceptable or better, they cannot qualify for the IIHS' overall Top Safety Pick+ honor, given annually to the safest models on the market.

Fullsize GM SUVs have a problem that's making owners sick

Some fullsize SUV owners are getting sick, thanks to a buffeting and vibration problem in 2015 model year examples of the Chevy Tahoe and Suburban, Cadillac Escalade, and GMC Yukon. According to owners' complaints to the National Highway Traffic Safety Administration, the issue can vary from an annoying vibration inside the cabin to an experience so severe that it leads to dizziness and headaches. General Motors is aware of the complaints, but the fix isn't so simple. According to spokesperson Tom Wilkinson to Autoblog, the company "has been tracking this issue for a while." The problem has a fairly low incidence rate, but when it does occur the issue can be "uncomfortable and annoying for owners." There's no precise cause for the issue, Wilkinson claims, and in some cases, simply balancing the tires or changing the door seals can make it go away. However, not all of the fixes are so simple. AutoGuide dug deep into the problem and discovered a GM preliminary information bulletin that advised dealers to remove the headliner and to check the roof's bonds to the bows that go across the vehicle. However, that document included a note that the solution might not entirely eliminate things. According to AutoGuide, adding Dynamat insulation to the roof sometimes helped the problem. A GM spokesperson also told AutoGuide the company fixed the problem at the end of the 2015 model year, and didn't go into any more detail. This roof issue seems linked to some of the worst droning in these SUVs. According to one complaint from a 2015 Suburban owner to NHTSA: "Roof will not remain attached to the roof bows. This causes the buffeting similar to a window being down when all are up. The results span from annoying to painful." A 2015 Yukon owner claims to have another alleged cause for the problem in a NHTSA complaint from February 2015. This person brought their SUV to the dealer seven times over the course of four weeks for vibrations. The dealer replaced the driveshaft, suspension components, and more, but nothing worked. According to an engineer to the service adviser: "In an effort to prevent roll overs, they designed the frame and body mounts too stiff. There are 40 engineers working on issues, they have no solutions that work across the board." Wilkinson told Autoblog that GM is working with customers on an individual basis to rectify things. Since these are newer vehicles, dealers should also fix the problem under warranty.