subject: Tips On How To Pass A Smog Test [print this page] Learning how to pass a smog test is one of those essential bits of knowledge that every car owner in California should know. But there are a lot of pitfalls involved in passing a smog test. Some people inadvertently shoot themselves in the foot doing things that they'll think should help them pass a smog test but in fact cause them to fail. The biggest thing that people do wrong is buying more expensive fuel. People often have a conception that how to pass a smog test is to use premium 91 octane fuel. It seems to make sense right? More expensive fuel is probably more pure, which means it probably burns cleaner and gives off less emissions right? Wrong. 91 Octane fuel contains higher combustive chemicals, which means it's formulated to burn longer, in higher performance engines. If you put it in an engine that's not meant for high performance, the fuel won't completely burn up inside the chamber, meaning that every time a piston fires, a little unburnt fuel will be pushed out of the exhaust, causing much MORE emissions to come out of the engine. Buying premium gasoline for your smog test can cause an ordinarily healthy engine to fail miserably. Don't do it.
Now I'm just as environmentally friendly as anyone. Some people argue that altering your normal engine habits in order to pass smog is cheating and non-ecofriendly. To a certain extent I am forced to agree. But most vehicles that fail smog fail by only a slight amount. Not only that, but older, classic vehicles made before 1971 aren't required to be smog certified at all, which doesn't seem to make sense. It's my opinion that it's better to save your money in hopes of one day buying a better, more fuel efficient, low emission vehicle than to spend your hard earned cash fixing up the junker with outdated technology. If I had a choice, I would rather save up my money in hopes of buying an ecofriendly car than spend my money fixing up the junker. But that's just me. The good thing about these tips on how to pass a smog test is that they won't work for the truly polluting vehicle. Like the picture to the right, some vehicles will simply fail smog anytime. That's why these tips are so great, because they only help cars that are already clean, not the truly dismal vehicle. So lets get to them! Tips on how to pass a smog test:
1) Use low Octane Fuel -- The lower the octane the better. We already saw that using high octane fuel can cause your vehicle to fail its smog test. Go the other way. If you can find 85 octane fuel, use it. Don't use this sort of thing on a permanent basis though, just for the smog test. What happens is that lower octane fuels burn up faster while still in the combustion chamber, giving your engine the maximum amount of time to incinerate those pesky emissions, before sending them on their way.
2) Use Isopropyl Alcohol -- That's right rubbing alcohol. This step goes in conjunction with the first step. If you use a combination of rubbing alcohol and 85 octane gas, you'll be almost sure to pass a smog test with flying colors. Don't overuse the rubbing alcohol though. For safety, only use 1 part rubbing alcohol per 10 parts regular fuel. A rubbing alcohol, 85 octane fuel mix will also cause your engine to burn hotter, which is a plus because the hotter the engine, the better the emissions will burn.
3) Use a Fuel Injection Cleaner a Few Weeks Beforehand. It's definitely always recommended for both your engine and your fuel system to be as clean as possible before you take them down to the old smog station. A few weeks before your trip, pour a bottle of fuel injection cleaner into your gas tank when you go for a fill up at the gas station. This will hopefully take care of some of the gunk and grime clinging to your fuel system.
4) Use a Fuel Treatment System. If you're really worried about passing your smog test, buy a fuel treatment system that specializes in lowering emissions.
