Ram, GM, and Ford are keeping the V8 alive

US automakers are bringing back their gas-churning V8 engines as federal regulators relax climate rules.

Brandon Bell/Getty Images Detroit's Big Three are going back to their roaring V8 roots.

V8s were on death's doorstep as federal emissions regulations bore down on automakers.

Now, as Washington pulls back on climate rules, the V8 trucks and muscle cars are making a comeback.

For years, the growl of a big, manly V8 engine had been fading from US auto assembly floors.

No longer.

A V8 is a gas engine with eight cylinders arranged in a V-shape.

It has long been a go-to choice for Americans who want the power to tow, haul, or go very fast — though it generally uses way more fuel than smaller engines.

Now, even as gas prices rise, the V8 is getting a new lease on life.

Washington has relaxed emissions rules, eliminated companywide fuel-efficiency fines, and ended the federal EV tax credit .

Automakers are responding with new and revived V8-powered trucks and performance cars, betting that Americans' appetite for big vehicles still has plenty of runway.

Data suggests demand for big, gas-powered vehicles — particularly trucks — remains strong.

According to Cox Automotive, US consumers spent about $15 billion on full-size pickup trucks in December alone.

"Consumers wanted these cars," Kevin Roberts, the director of market intelligence at CarGurus, told Business Insider.