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05-14-2007, 01:09 PM | #1 | |
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Efficiency Modifications
I recently bought a ’99 Mazda Protégé and I was looking to do any modifications that would increase my gas mileage. I’ve also read a number of articles saying the best way to increase gas mileage is to adjust your driving habits (ie: drive less, at the speed limit, etc). But in terms of modifications, the only recommendation I’ve gathered is to replace the stock air filter with a performance K&N filter. Are there any other modifications that are well accepted to improve mpg? Can I expect increased horsepower or performance coincidently with the mpg boost?
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05-14-2007, 02:09 PM | #2 | |
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Re: Efficiency Modifications
keep your tires aired up to 100psi, and take the sawsall to anythign that isn't absolutely needed, and even some things that are needed to get the weight down to as little as possible.
In short, no, there's not much you can do, engine wise. The efficiency of the engine is way too cost prohibitive to make any real attempts at changing it. You're way better off buying a more efficient vehicle.
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05-14-2007, 03:10 PM | #3 | |
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Re: Efficiency Modifications
... and please dont inflate your tires to 100psi
although inflating them to the max listed on the sidewall will help tremendously. typically, they are inflated a lot less by the dealer and service stations |
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05-14-2007, 03:14 PM | #4 | ||
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Re: Efficiency Modifications
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I'll leave 'proper' tire inflation to one of the several tire threads, since its not a simple subject
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05-14-2007, 06:59 PM | #5 | |
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Re: Efficiency Modifications
well at least with a sawzall you are in control of what is being removed
with 100 psi in your tires, you would probably loose the whole car in one fell swoop if you tried to turn |
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05-17-2007, 11:34 PM | #6 | |
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Re: Efficiency Modifications
Do not buy a K&N filter man. That's a performance filter that clearly states "HIGH FLOW FILTER" on the box. High air flow = more fuel in cylinder in order to get proper combustion. In the end, more fuel burnt per stroke = less fuel efficient. Unless you're trying to squeeze out power, high flow filters are useless.
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05-18-2007, 04:24 AM | #7 | |
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Re: Efficiency Modifications
to improve MPG you need to set a lean mixture in the cyliders, to get high performance you need to set a rich mixture, even though with modern electronic control system, its still hard to converge two points perfectly.
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05-18-2007, 04:57 AM | #8 | |
That thing got a Hemi?
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Re: Efficiency Modifications
no, you need a 14.7:1 air/fuel ratio. it doesn't matter what state of tune your engine is, 14.7: is the optimum A/F ratio.
running lean can cause pre-detonation and can damage pistons/valves/heads/etc. running too rich can cause cylinder wall washing and increased wear.
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05-18-2007, 09:18 AM | #9 | |
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Re: Efficiency Modifications
Stoichiometric value is the best value for good efficiency of catalyst, but to get the MAX power, its better to set a mixture ratio slightly less than 14,7
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05-18-2007, 09:20 AM | #10 | |
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Re: Efficiency Modifications
yes, for maximum power a slightly lean mixture provides better burn.
the downside being that you can't do that too much because of the temperatures involved. many race cars run slightly rich because the extra fuel in the mix lowers combustion chamber temps.
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05-18-2007, 09:20 AM | #11 | |
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Re: Efficiency Modifications
detonation can be solved by ECU, reducing the ignition advance
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05-18-2007, 09:22 AM | #12 | |
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Re: Efficiency Modifications
<14,7 should mean rich.....i suppose...
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05-18-2007, 09:10 PM | #13 | ||
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Re: Efficiency Modifications
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05-21-2007, 06:41 PM | #14 | ||
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Re: Efficiency Modifications
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05-22-2007, 11:35 AM | #15 | ||
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Re: Efficiency Modifications
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Keep properly inflated tires, drive like a grandma, and enjoy. There really isn't much else you can do. Most factory fuel curves are one step on the rich side to prevent detonation and reduce NOx (at the expense of HC) emissions. Having someone reprogram for a little less fuel might save you a half of one mpg, but it might cost $300 to do the work. Compare the cost versus what you save and see how long it will take to recover. Other things you can do; run thinner tires. Contrary to popular belief, tire width does not affect how much rubber is contacting the road, it simply affects the shape of the contact patch. A long skinny contact patch provides less rolling resistance than a short fat one. Also select touring-type tires instead of performance tires. The smaller treadblocks not only help wet and noise performance, they offer less rolling resistance. Avoid fuel additives or high octane fuel. Wastes of money.
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