I get the strangest e-mails sometimes. In guess people think I just have the answers to everything. Here’s one:
Dear Depleted Cranium
The price of gas keeps going up but I can’t afford a new car and I really just want to figure out if there’s a way to make my car run more efficiently and burn less fuel. It would be nice if it made the performance better too. I really am more interested in saving gas. I keep seeing all these products that go onto the gas line or the air filter or somehow are connected electrically. I keep hearing that they are scams. They sound too good to be true, so probably are.
Is there something that is not a scan that will boost my cars fuel mileage?
The internal combustion engine is a mature technology that has been tweaked and tinkered with for many years. The car business is cutthroat so manufacturers are trying to make their engines as efficient as possible. If there was a simple device like a magnet you could slap on to make the car burn fuel better it would come standard. A few more miles per gallon is a big deal in the automotive industry, especially at today’s fuel prices.
That said, there are a few things that could potentially improve the fuel efficiency of a car and also boost performance, but not by a huge amount:
- Keep the car well maintained and tuned – In a new car this is not going to make any difference, but as time goes on, spark plugs wear out, potentially resulting in less perfect ignition. Fuel injectors can get dirty and oil degrades. Just keep the car in good repair and it will provide the best fuel economy possible. Check the owners manual to see how often you should bring it in for a tune-up. Also keep the tires properly inflated. But don’t expect any of this to make that big a difference. Unless the car is in pretty bad need of maintenance, it won’t make a noticeable difference.
- Add a cold air intake – I am a little hesitant to suggest this, because in my experience it really does not produce any improvement you’ll notice, but at least in principle, if you can get the intake air temperature cooler, it will improve overall engine efficiency. Most engines take in air under the hood where it’s already pretty hot. A good cold air intake sucks in air from an area where it has not been preheated much by the engine. It also should not restrict the flow of air by much, since that makes the engine work harder. I’d recommend against putting one in if you don’t know what you’re doing, because improper installation can cause a lot of problems, some of which could ruin your engine. And in any case, don’t expect this to make more than a very modest difference.
- Upgrade to a low resistance exhaust system – The exhaust system you choose for your car never will improve the performance of the engine directly. An engine will always do best if it has no exhaust system at all, and just vents out the gas directly from the exhaust manifold. That would be very loud and dirty, however, and modern regulations require a catalytic converter. Pushing the exhaust through the piping, the catalytic converter and the muffler makes the engine do a little extra work. Therefore, if you install an exhaust system with less resistance, such as larger pipes and a less restrictive muffler, it can result in the engine generating slightly more horsepower from the same amount of fuel. Again, don’t expect anything major from this. Most people who put performance mufflers on their car really just want it to sound loud and obnoxious. Making the exhaust system actually as low resistance as possible requires completely rebuilding it, which is expensive and probably not worth the modest savings you’ll get.
- Modify the ECM Code – I am again hesitant to include this one, because usually it’s more trouble than it’s worth. Modern cars have an electronic engine control module which can often be modified by using a programer or by replacing the original ECM with one that is modified with new firmware. Most car manufacturers code their ECM to provide the best compromise between fuel economy, performance, engine response and so on. In some cases, it’s possible to gain more of one of these by making trade offs on the others. For example, some modifiers can squeeze a tiny bit more power out of their engine by sacrificing fuel economy. It’s also possible that you could make the engine use a little bit less fuel if you tweak it to rev up a bit slower or change other aspects of the engine. I don’t really recommend this, especially if you’re not sure of what you’re doing, and because you will ultimately end up having to make tradeoffs somewhere, since the manufacturer already does a pretty good job of balancing performance, fuel economy, reliability, response and so on.
- Add a turbocharger – This is probably the one thing that can actually result in a major increase in performance and overall efficiency to an internal combustion engine. It uses a turbine, powered by the exhaust flow of the car, to spin another turbine that compresses the intake air before it reaches the engine. Because the engine gets more air, it can operate more efficiently. This will almost always produce better performance. It may also improve gas mileage, but that really depends on the engine and how you tune it. You will definitely need to reprogram the engine controller if the engine did not come with a turbo charger.There may be complications. Not all engines can take the added compression, the additional compression may require you use higher octane fuel in the engine, which would defeat any potential savings and the turbocharger can be difficult to install depending on the car. Turbochargers get very hot and therefore may need additional cooling components. Installing them requires re-routing the engines exhaust and intake air. It’s a complex job and not all engines provide a good place to locate the turbocharger.Turbochargers are expensive, especially when you factor in professional installation, which is required unless you really know what you are doing. They may or may not actually result in a noticeable improvement in mileage. When they do, it’s still not generally going to result in enough savings to pay for the cost of installation. For this reason, turbochargers are generally installed for performance reasons but not to provide improved fuel economy, at least not in gasoline engines.
I’m sorry but that’s pretty much it. Aside from other basic things like trying to accelerate gradually and not gun the engine too much, avoiding any unnecessary items mounted to the outside of the car, which may increase drag and things like that, those are really the only things you can do and they probably won’t help enough to make them worth the effort, with the exception of keeping the car well maintained, which is always a good idea anyway.
This entry was posted on Sunday, February 26th, 2012 at 2:30 pm and is filed under Good Science, Misc. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
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