Delayed update: I flushed out the tranny a few weeks ago and replaced it with GM Synchromesh FrictionModifier fluid after plenty of research on the subject. Its definitely shifting better. I was glad to see very little debris in the old fluid with just one large yet flat piece. I also recently re-gapped my NGK plugs and sanded clean the distributor rotor and ignition points. That made an instant improvement. Im certain this all will lead to improved efficiency as everything is functioning better.
How-To: Better MPG
- Thread starter HeX
- Start date
Awesome thread here, @HeX 
I don't have any tips to add, but I do have a few questions that'd be nice to have cleared up, possibly on the front post. I'm especially interested in the intersection of longevity and efficiency, since my primary concern is making the car last as long as possible. What effect do spoilers have? I imagine detrimental, but by how much? Would adding an insulation shroud to the hood help? Cold air intakes? Fuel additives / valve cleaners? I've heard some about inline catalytic converters or something too, am interested what difference they make to emissions and efficiency.
I don't have any tips to add, but I do have a few questions that'd be nice to have cleared up, possibly on the front post. I'm especially interested in the intersection of longevity and efficiency, since my primary concern is making the car last as long as possible. What effect do spoilers have? I imagine detrimental, but by how much? Would adding an insulation shroud to the hood help? Cold air intakes? Fuel additives / valve cleaners? I've heard some about inline catalytic converters or something too, am interested what difference they make to emissions and efficiency.
I don't see a spoiler having any effect on your car, possibly could cause extra drag and reduce gas mileage but it's such a small amount you will never notice it. What's adding insulation to the hood supposed to do? Cold air intakes are just for looks and sound (at least on a old civic), I never noticed an increase or decrease in mileage by adding an intake. You want a valve cleaner, take an empty spray bottle and fill it with water, while the engine is running slowly mist the intake (with filter off) and empty the bottle, this will steam clean the entire combustion chamber including the valves that you speak ofAwesome thread here, @HeX
I don't have any tips to add, but I do have a few questions that'd be nice to have cleared up, possibly on the front post. I'm especially interested in the intersection of longevity and efficiency, since my primary concern is making the car last as long as possible. What effect do spoilers have? I imagine detrimental, but by how much? Would adding an insulation shroud to the hood help? Cold air intakes? Fuel additives / valve cleaners? I've heard some about inline catalytic converters or something too, am interested what difference they make to emissions and efficiency.
Read this... http://www.clubcivic.com/forum/threads/manual-transmission-flush-options.228889/
I came to the conclusion that GM Synchromesh Friction Modifier is awesome in manual tranny Hondas and post-2000 Honda manual tranny fluid isnt what it use to be.
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Thanks.Awesome thread here, @HeX
I honestly dont see much of a functional benefit to spoilers for regular usage on these efficient engines. Spoilers are traditionally more for adding rear wheel traction during higher speeds, which isnt bad but not a big deal on a sub-115hp FWD vehicle. They dont weigh enough to bog down performance significantly, but it all adds up depending on whats you've added to your vehicle.
I have to give the hood insulating liner some thought as I can't currently think of an immediate benefit for the sake of efficiency.
Cold-air intakes are a waste of money in fuel efficient vehicles. A drop-in K&N filter is all the extra breathing help you'll need.
Fuel additives are great when you use the few good ones there are in the market. SeaFoam and Techron are the most effective ones from my experience and research. I have yet to try Royal Purple's new stuff but I've read good things thus far. Those cheap $2-$3 cleaners don't do any better than rain on a dirty car (it might get a thin top layer of dirt off, but nothing reasonable). I recently tried SeaFoam Top-engine cleaner and experienced great results as I read everywhere prior to deciding to try it. You can't go wrong with SeaFoam products.
I definitely disagree with this. You're promoting water to mix with fuel, so it's not "steam cleaning" but encouraging deposit build-up by affecting the air/fuel combustion chemistry (at least in my theory). The water can't be heated independently from the fuel, and fuel combustion temperature (~260 degrees C) will far exceed steam temperature (100 degrees C). Even if you could introduce steam independently, it'd have to be at a high PSI in a concentrated point to even try to break up carbon deposits. Stick to The SeaFoam top-engine cleaner because it works at a chemical level.
Ctag, Im not sure what you refer to as "inline" catalytic converters, so please do elaborate.
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Thanks guys, was just hoping to open up more ground for discussion.
I heard somewhere that they put that fiberglass-looking shield on the inside of hoods to hold heat in and make the engine slightly more efficient. No idea what the real purpose is, except maybe to help the engine heat up fast in cold weather?
@HeX, I misspoke. Meant to query about high flow cats, but it looks like they just have a different density of the catalyst.
I heard somewhere that they put that fiberglass-looking shield on the inside of hoods to hold heat in and make the engine slightly more efficient. No idea what the real purpose is, except maybe to help the engine heat up fast in cold weather?
@HeX, I misspoke. Meant to query about high flow cats, but it looks like they just have a different density of the catalyst.
Two reasons for hood insulation. One is yes, to help the engine get to ideal operating temp sooner. The other is to protect the paint on the hood from the extreme heat generated under the hood.
I would avoid high flow cats and stick with OE if efficiency is your goal. OE cats are designed to work with OE oxygen sensors and will deliver the best fuel efficiency.
Thanks. Im glad to see people are appreciating and benefiting from this thread. Mission, accomplished.
Tire pressure & quality is #4 on the suggestions list in the first post. It definitely makes a big difference in some climate areas more than others. I imagine that such ~60 degree swings in your area would deem checking tire pressure weekly.
I know about the heat reflection for the sake of hood paint, but being that this topic is about efficiency I don't really see the benefit or detriment to engine bay temperature except that perhaps it forces heating out from the center and towards the hood seems to breathe out.
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You definitely have.
@ctag , I read that article and dont fully agree with what it says about all catalytics having the same design. Build quality is one of the biggest differences with cat quality. Anyone who's compared a quality cat (MagnaFlow) with a generic cat at a muffler shop will see and feel obvious differences. I think theyre accurate in that the inner coating quality makes a huge difference, but I dont think thats it. Im not certain but I believe some companies use the similar honeycomb style but with different spacing and flow direction, which is where additional flow ease comes to play. Furthermore, if a cheap cat begins to fail they usually start collapsing inside and clogging flow, which can be a slow process. Id trust that to happen more efficiently with a Magnaflow than a cheap one.
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Here's the actual article @ctag referenced for those who care to read it.
http://www.catalyticconverter.org/news/news_page.cfm?Key=catalytic_converter-&News=89
There are many companies on the web today selling what they call a "high flow" or "performance" catalytic converter. We get calls almost everyday from customers wanting to know how much a "high flow" or "performance" catalytic converter will cost for their car. Well this may come as a surprise to some and will really bust the bubble of what some companies are selling, ....THERE IS NO SUCH THING AS A HIGH FLOW OR PERFORMANCE CATALYTIC CONVERTER!! A catalytic converter has no moving parts nor is chambered like a muffler, or have elaborate packing like a muffler. It's interior is not designed to move exhaust gasses along more quickly such as having a spiral core.
A catalytic converter is designed to reduce harmful exhaust gasses...that's all! Basically all aftermarket cats have a ceramic substrate (the guts) that during manufacturing is coated with a solution of platinum, palladium and rhodium. This coating is what causes the catalyst reaction once the converter reaches a certain temperature supplied by the vehicles exhaust gasses.
These substrates are made like a beehive honeycomb and are comprised of 400 cells per square inch across their surface. In theory, an aftermarket cat is higher flow than it's O.E. counterpart, because the O.E. converter has a substrate made up of 700 cells per square inch, so the exhaust flow with an aftermarket converter is a little freer, but not dramatically! We do carry a few universal converter numbers that have a 200 cell substrate but they are like I said, universal. They sometimes require extensive welding and cutting of the original exhaust system, so for many applications these are just not practical.
Okay that's it!! There is no Magic "Super Free Flow" Catalytic Converter out there and any company that tries to sell you one is not quite telling you the truth, The sad thing is, there are some web sites claiming they have High Flow Performance Cats, and by the way at a huge inflated price, when in fact all you will be buying is the same converter you would buy anywhere else for half the price. So that's the story in a nutshell. But if you're still determined to find a High Flow catalytic converter or your buddy told you he got one from XXX Auto Parts, try to remember what you've read here and ask some real questions about the product. Like how many cells per inch are across the surface of the substrates or how many grams of precious metal wash coat is baked into the substrate? If it's below 25 say thank you and leave quickly. If the coating is less than a 25 gram mixture the cat will not do the job, and it will set off the check engine light. You might be surprised to find questions like these will throw most sales people for a loop. Most will have no clue what you are talking about, so just be careful. Okay, if you are now totally confused about the myth of High Flow, Go Flow, Mo Flow catalytic converters and would like to talk more about them...give us a call we'd be happy to hear from you.
http://www.catalyticconverter.org/news/news_page.cfm?Key=catalytic_converter-&News=89
Is there really such a thing as a High Flow or Performance Catalytic Converter?
Read the following story and you might be surprised!
There are many companies on the web today selling what they call a "high flow" or "performance" catalytic converter. We get calls almost everyday from customers wanting to know how much a "high flow" or "performance" catalytic converter will cost for their car. Well this may come as a surprise to some and will really bust the bubble of what some companies are selling, ....THERE IS NO SUCH THING AS A HIGH FLOW OR PERFORMANCE CATALYTIC CONVERTER!! A catalytic converter has no moving parts nor is chambered like a muffler, or have elaborate packing like a muffler. It's interior is not designed to move exhaust gasses along more quickly such as having a spiral core.
A catalytic converter is designed to reduce harmful exhaust gasses...that's all! Basically all aftermarket cats have a ceramic substrate (the guts) that during manufacturing is coated with a solution of platinum, palladium and rhodium. This coating is what causes the catalyst reaction once the converter reaches a certain temperature supplied by the vehicles exhaust gasses.
Okay that's it!! There is no Magic "Super Free Flow" Catalytic Converter out there and any company that tries to sell you one is not quite telling you the truth, The sad thing is, there are some web sites claiming they have High Flow Performance Cats, and by the way at a huge inflated price, when in fact all you will be buying is the same converter you would buy anywhere else for half the price. So that's the story in a nutshell. But if you're still determined to find a High Flow catalytic converter or your buddy told you he got one from XXX Auto Parts, try to remember what you've read here and ask some real questions about the product. Like how many cells per inch are across the surface of the substrates or how many grams of precious metal wash coat is baked into the substrate? If it's below 25 say thank you and leave quickly. If the coating is less than a 25 gram mixture the cat will not do the job, and it will set off the check engine light. You might be surprised to find questions like these will throw most sales people for a loop. Most will have no clue what you are talking about, so just be careful. Okay, if you are now totally confused about the myth of High Flow, Go Flow, Mo Flow catalytic converters and would like to talk more about them...give us a call we'd be happy to hear from you.
Thanks @HeX, that makes good sense with the catalytic converter.
I'm also curious about cylinder compression; again, I don't really even know the basics here. People discuss increasing the combustion compression, does this have a noteworthy affect on mileage or engine degradation? Some quick online searching indicate that people to think it helps mileage, but has more emphasis with diesel engines? I'd like to do some first-hand testing and find out, would need to find a local place to rent one of those compression gauges from first..
I'm also curious about cylinder compression; again, I don't really even know the basics here. People discuss increasing the combustion compression, does this have a noteworthy affect on mileage or engine degradation? Some quick online searching indicate that people to think it helps mileage, but has more emphasis with diesel engines? I'd like to do some first-hand testing and find out, would need to find a local place to rent one of those compression gauges from first..
Keep researching.
as you raise compression with different pistons/head gaskets you have to change your spark timing and increase the octane in your gas to avoid pre-ignition. Higher octane gas costs more than you will save by the better gas mileage. Smaller ways to change compression is with a turbo. You can adjust it so you raise compression just below the point where you need to increase the octane of your gas. Or you cool the air with methanol, intercooler or nitrous oxide. But again, costs way more than you will ever save by the better gas mileage on a gasoline engine.
As far as improvements from an engine with abnormally low compression -you have to first find out if it is low before you even ask. No engine runs optimally when its not running optimally obviously, but it depends how low it is. I ended up replacing a motor that had compression levels around 90-100 psi with a motor with good compression and had no difference in gas milage. But improvements are all relative to how bad it is, so find out what yours is first. And make sure to learn how to do a compression test properly before doing it. Many people do it wrong and get improper readings.
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By text book you may be correct but real world experiments would show that it works, test it out on your car then pull the head and look at how spotless the piston tops or valves are. Just look at what happens when you blow a head gasket and burn water in the combustion chamber in one cylinder, that piston will be clean compared to the others. I wouldn't doubt that the intake might build up a little dirt grime if you have a crappy filter or just drive a lot of dirt roads, I have no issue with seafoam I'm just saying you can also use water which is free or cheap
well the whole wing thing on a any cars has a functionality, goes by how physics works. the wing has multiple function all different on different drintrain. the wing doesn't become" less functional just cause its on a fwd fyi doesn't matter how much hp the car has higher hp just mean the car can now move from point a to b in a much quicker time then it did in stock form. the wing on a fwd keeps the car stable under high speeds. and in cornering wise it helps even great by keeping your rear wheels planted on the road this always been a common problem for fwd not enough weight in the rear. which increases understeer when going around corners
His point was more that these cars aren't capable of the high speeds where this is helpful in their stock form. If you want to corner nicely at higher speeds you first have to increase the engines hp and then changing your suspension and tires will do far more than a stock spoiler would. On these cars they are mostly for looks. Other cars not so much, but the back end of a civic is plenty heavy enough to give proper tires traction at higher speeds.
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to be honest with you cars with lesser hp doesn't necessarily mean they can't do high speed runs.... it just take the car longer to get to those higher speeds... Germany is a perfect example they have plenty of car in the same hp range as a 93 civic dx going on autobahn.normal average highways speed there is around 85-90 mph lots of other European countries have highways that has higher speed then ours also yes in the drag world it doesn't really matter s much cause all you need is a flat wing to keep it stable going down the strip
Of course not! ive been in a stock toyota echo doing 185km/hr and i took a 63hp festiva to 175 down a big hill, but it takes miles to get a civic to that speed on the flat. Most tracks you couldnt get a stock civic up to high enough speeds to want a spoiler and if the track was that open youll just want to slow down before the turn and it wont affect your time that much because having a spoiler would just slow you down on the rest of the track in that case. Having driven an 89 and 91 hatch, owned '01, '02, '03 sedans and an '05 coup (all civics) i can say that every single one had understeer. My daily driver hatch has a good balance between understeer and oversteer but the civics always had understeer. With fwd it depends a lot on how you drive it, if you drive the same as you would a rwd your going to oversteer, be slow, and a spoiler will not help you. 80-90 mph is not fast, if your having problems at those speeds you need better tires or suspension. But this guy was asking about efficiency, not downforce, so to answer that a static/stationary spoiler that is doing its job will reduce your gas milage as its designed to push your car down. However if its just for show like the ones on civics and cobalts most likely are then it may not do anything. In either case its probably not noticeable and your probably safe just going with the look you want and not thinking about efficiency. Unless your getting an aftermarket one, then who knows. That advice was for a factory spoiler.
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Interesting. If youve tried it and seen it work then Ill take your word for it.