Not only have gas prices changed dramatically over the years, so have the gasolines themselves. You see, the federal government is very concerned with the environment, and they have mandated over the years that certain chemicals be put into gasoline to make them burn better for a cleaner environment. Well, that’s a good thing, but it has a downside.

Some of these chemicals tend to leach out and they form deposits inside the engine, like on this valve on the left. That big mound of crud can affect performance, it can affect fuel economy, and it can even affect emissions, and that all comes from gasoline.

It should look more like the valve on the right, no deposits at all. What can you do to prevent that? Well, you can use a fuel injection cleaner on a regular basis. Follow the directions. Your better ones, you can probably go longer between applications, but they’re going to cost more. Now one big thing to remember here - more is not better and could be damaging to your vehicle. So use the directions, follow them.

But there’s something else that is new that you’re apt to run across. You may see the term TOP TIER on a pump. TOP TIER is a type of gasoline that was developed by four companies: Honda, Toyota, General Motors, and BMW. They’re aware of the problems with the deposits, and they said if we set a standard for these fuels, we can do away with these problems. And the fuel just has more additives. It’s like the fuel injection cleaner. It helps keep these deposits under control.

So if you see TOP TIER on the pump, it means that it’s a higher detergent gasoline, and if the price is appropriate - you don’t want to pay too much here - then it would be a good choice. General Motors has even come out with a technical service bulletin, such as we have here, that explains this to technicians so that technicians should be aware of it. And remember that to qualify for top tier the additives have to be in all three grades, not just in the premium grade, so you aren’t forced into buying premium for your 87 octane car.

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