Today’s diesel powered cars are a far cry from the noisy, smoke-belching vehicles of years ago. Today’s diesels are cleaner and quieter; so why are there so few in the US? In Europe, some 50% of the passenger cars on the road are diesel, in the US, about 4%. Polls reveal that Americans just aren’t comfortable with diesel engines and some say it has to do with a diesel engine made by Oldsmobile in the 1970s. Here’s the story:
In the mid-1970s, the US federal government issued a set of very restrictive emission regulations. In order to meet these new regs, executives at General Motors decided to engineer a new diesel engine for passenger car use. The reason was simple, diesels were not subject to the same federal emissions requirements. The job was handed over to the Oldsmobile division and the rush to build a V8-based diesel was on.
The first Olds diesel cars hit the dealer’s lots in 1978 and – the engines failed quickly. Ask any automotive enthusiast and they will tell you that the problem was that GM engineers “used GM’s standard 350 block designed for gasoline cars.” However, this isn’t true. The service techs at know the story well and tell us the trouble came from the cylinder heads alone. Here’s what happened:
Diesel engines have higher compression ratios than gasoline engines do and this puts higher stresses on cylinder heads and engine head bolts. This usually means engineers usually use more head bolts and stronger ones than they do on gasoline engines. But, in order to keep the tooling simple, the engineers at Oldsmobile maintained the same 10-bolt pattern and head bolts as the older 350 gasoline engines. This proved to be a disaster because the bolts and heads failed during use.
Even though improvements were eventually made in the , it was too late and this caused a massive class-action lawsuit against Oldsmobile. In fact, as the story goes, the Oldsmobile diesel debacle was so bad that it spurred lawmakers in many states to draft the first “lemon laws.”
So, today we may be seeing the result of this: an American consumer who is suspicious of “American-built Diesels” and perhaps diesels in general. This, of course, is a shame because there are quite a few excellent diesels on the market, in particular the Cummins diesels that have been installed in Chrysler products for quite a few years now.