Showing posts from February, 2012

O2 for You

Oxygen sensors are by far one of the most important sensors used to control the engine. This sensor does just what the name implies, it senses oxygen but specifically it looks at the oxygen content in the exhaust stream. When the computer that controls the fuel injectors needs to see if it is doing a good job managing the air/fuel ratio it will look to the O2 sensor. The amount of oxygen in the exhaust is directly proportional to how much fuel the injectors are adding to the incoming air. If oxygen content is high it indicates a lean mixture which means that there is not quite enough fuel. If oxygen content is low it indicates a rich mixture or a situation with too much fuel. The O2 sensor is a voltage generating sensor. An electrode extends from the senor tip into the exhaust stream so that it can pick up oxygen molecules in the exhaust. The other end of this electrode extends out of the exhaust and is actually exposed to ambient air on the outside of the exhaust pipe. This electrode

The Worst Cars In the World: Cadillac Cimarron

What a major embarrassment! Cadillac was already skidding out of control when the Cimarron was released, and this car did nothing to help them. This huge mistake of a car was actually symptomatic of deeper problems at GM as they were starting to lose market share in a way that they had never known. The Cimarron makes the Cadillac Catera, Caddy’s subsequent attempt to build a small car, look like a fantastic bit of engineering. Look at the fancy emblems on the taillights. In the early 80’s the effects of the Middle East oil embargo of the seventies were still being felt and many auto companies were downsizing their vehicles so that they could be more fuel efficient. Front wheel drive was also starting to catch on. Cadillac had a history of building huge land yachts for people who might generally have more dollars then cents. Nevertheless, they felt it important to come up with an offering that would provide better fuel economy but still pamper the driver and passengers with the amenitie

Not Political, Just Stupid

The Chrysler commercial that played during halftime of the Super Bowl has generated a lot of buzz. Many political pundits on the right are saying that it is an ad that endorses President Obama because it talks about how it’s halftime in the Super Bowl but in the grand scheme of things it’s halftime for America, and we are going to come back strong in the second half. The right wingers are saying that the commercial is trying to say that Obama will lead this country towards greatness if he is reelected, and since this is an election year, we are at the half-time of his eight years in office. The ad talks about the ways that we are going to recover from the economic hard times that have befallen this country. Talking about Detroit and how hard things have been there for the last several years but the people there have not given up. All the while never actually showing much of anything that is in Detroit and the ad also starred Clint Eastwood who doesn’t have anything to do with Detroit.

Nasty Gases, and Other Things You Don’t Want to Breathe

What is the stuff that is actually coming out of the tailpipe of your car? Is there really any cause for concern or are those that say the pollution from cars will kill us all just crazy? As with most controversial topics, the truth is usually somewhere in the middle. The stuff that comes out of the tailpipe is formed as part of a simple chemical reaction. We need to have a look at this simple chemistry. The gasoline that is burned in the engine is made from a combination of hydrogen and carbon. Gasoline typically has a molecular formula somewhere in the neighborhood of C7H16 to C8H18. These are heptane and octane. In order to burn the gasoline we must also have oxygen which is O2. This oxygen is in the atmosphere and is mixed with the air that makes its way into the combustion chamber. The other thing that is in the air is nitrogen which is known as N2. Nitrogen isn’t required to make combustion happen but since it’s there when this chemical reaction is occurring, it will have an impa