The Oldsmobile Diesel & Its Outcome
Here's the story of General Motor's diesel V8, which highlights one of the silliest things done in automotive history:
During the mid-1970s, meeting new federal EPA emissions regulations was resulting in issues for car manufacturers and their dealerships. The solution, at least to some General Motors executives, was to rush some diesel engines to the marketplace. According to StorkAuto, this was probably because diesels were not subject to the same emissions requirements as gasoline ones.
Mercedes and Peugeot had both been successful selling diesel vehicles in the U.S, so people didn't see why General Motors wouldn't be Though the new GM-designed diesel engines were destined for GM car divisions, the design responsibility fell to GM's Oldsmobile group. Working at a quick pace, the first Oldsmobile-built diesels hit the dealership lots in the late 1970s, and there were problems—serious ones!
To start with, Oldsmobile powertrain engineers based their design on the division's existing 350-cubic-inch V8. It is a legend that GM engineers just slapped new diesel heads on the standard 350 block and did nothing else. What really happened is that the new block was reinforced substantially internally and was built of a sturdy cast-iron alloy; the blocks weren't the problem. The trouble came from the cylinder heads and the fuel system, the cylinder heads in particular. They broke an awful lot resulting in big problems for GMs dealer network.
How Diesel Technology Ties In
To understand the GM diesel situation, it helps to understand about diesel technology. Diesel engines work using a compression-ignition scheme. As gas is compressed, its temperature elevates, and, in the case of a diesel engine, it is compressed until the diesel fuel in the combustion chamber ignites. This leads to much higher combustion chamber pressures than are in a gas engine. Once again, much higher combustion chamber pressures than in a gasoline engine. Usually, diesel engines have more and stronger head bolts to compensate for the diesel's high cylinder pressure.
The Oldsmobile diesel, however, maintained the same ten-bolt pattern and head bolts as gasoline engines , and that was so that common production tooling could be used for both the gasoline and diesel engines. This was a huge mistake. There were also other problems with the engine: a fuel-pump timing chain that stretched and poor dealer service training, to name some. And, even in good running order they were just loud, and belched tons of smoke; all to provide acceleration that can best be described as modest.
Production of the Oldsmobile diesel lasted from 1978 until 1985. The car caused a class-action lawsuit that saw owners reimbursed for up to 80% of a replacement engine's cost upon failure. The engines were so bad that they spurred legislators in manystates to draft lemon laws. Ultimately, Oldsmobile-built diesels ruined the American consumer's appetite for diesels for almost thirty years. Only now are diesels starting to reenter the United States car market in small numbers—and most of those are from non-US makers. This is unfortunate because diesel technology is robust, proven and leads to tremendous fuel economy.