‘Trust me, I’ve done the research’: A Silverado owner sounds the alarm over dangerously thin oil in their truck

A truck mechanic and owner is telling people who own certain GMC and Chevy trucks to ignore the factory oil recommendation. TikTok creator Steve Moore, who owns a 2017 Sierra, made a video about the 2014 through 2019 model years of the GMC Sierra and Chevrolet Silverado. He says if you own one of these trucks, you need to switch from the recommended 0W-20 oil to 5W-30.

According to Motor1, Moore says there’s a specific reason manufacturers use that super thin oil, and it’s not about engine health. He explained that 0W-20 is simply the thinnest grade they could use. “The only reason they put 0-20 there is they were trying to find the thinnest oil they could run … with less drag on the motor,” he stated. He says this is because of government fuel efficiency standards. “Trust me, I’ve done the research on this,” he says. 

Moore believes the 0W-20 is “the bare minimum.” He prefers the thicker grade for better stability. “I’d rather more protection with a thicker oil,” he stated, adding that he runs 5W-30 in his own truck and it’s been performing “perfectly fine for a while now.” He insists the change “doesn’t change anything” negative about the truck’s operation.

Thicker oil provides better long-term engine protection

It’s true that 0W-20 is thinner and helps boost mileage in newer vehicles. However, 5W-30 is known to stay thicker for a longer time, offering better protection over the oil change interval. Official advice from some dealerships indicates the GMC Sierra 1500 generally takes 5W-30 full synthetic oil, only suggesting 0W-30 for extremely cold weather.

Moore also has another major recommendation for these trucks: remove the transmission thermostat. He noted that the transmission was designed to heat the fluid up, making it thinner to boost fuel efficiency. “When I first got this truck, I would drive it for 10 minutes and my transmission would be at 190 degrees,” he said. That’s far too hot for just ten minutes of regular driving. While unexpected repairs on GMC vehicles can be costly, this preventative step could save you money.

He recommends getting an inexpensive aftermarket kit to “delete the transmission thermostat,” which is also known as a thermal bypass valve. This modification allows for better cooling of the transmission fluid. Cooler fluid temperatures can greatly increase the lifespan of your transmission components.

Moore also recommends turning off the truck’s Active Fuel Management (AFM) system, also known as cylinder deactivation. This system is GM’s way of trying to improve fuel economy. “I don’t like it kicking into four-cylinder mode because it sounds funky, because I have dual exhaust on it.” You can buy an aftermarket kit to turn off the four-cylinder mode completely.

Other owners agreed with Moore’s advice in the comments. One viewer said AFM is a total “crapshoot,” citing a friend who had a 2015 Silverado that needed three engine replacements before it hit 30,000 miles. Another owner said they feel 0W-20 is too thin and they use 5W-30, especially once the vehicle hits higher mileage, like over 70,000 miles. 

Some truck owners have faced dealership disputes over repair costs, making preventative maintenance even more important. Moore’s reply summarizes his view: “Oh, it will work. So it’s just the bare minimum. I personally would just rather have a little more protection.”