Every rise in gasoline prices immediately prompts a series of Beginner-section threads asking how to increase fuel efficiency. As a committed fuel miser, I want to create this thread to spread my knowledge on fuel efficiency. If this takes off, I hope experienced members such as TheNextEpisode and Owequitit will contribute further with their knowledge.
I’m a genuine nerd; be prepared for a lot of reading. I’ll try and organize this as well as possible.
--
Maintenance
Our cars are now 19 to 22 years old – maintenance is key in keeping a smooth-running, fuel-efficient engine. This list of basic engine maintenance procedures should be able to somewhat maximize the potential of our F-series engines.
1. Basics
aaaaaa. IAC Valve – Idle Air Control Valve (cleaning)
aaaaaaaaaai. http://www.cb7tuner.com/vbb/showthre...hlight=diy+egr
aaaaab. PCV – Positive Crankcase Ventilation (cleaning/replacing)
aaaaaaaaaai. The PCV is located on the valve cover between cylinders #2 and #3. Remove the valve from the valve cover while the car is idling, and place your finger on the hose outlet. If the PCV is functioning properly, you should feel your finger being sucked in with suction. This is the easiest way to test if the PCV is functioning in the F22, but there are other methods you can find online. This is a $3 part that is easily accessed.
aaaaac. Throttle Body (cleaning)
aaaaaaaaaai. Cleaning the throttle body with some carburetor cleaner should free up the gunk left in by two decades of use. With the engine off, remove the intake tube and spray the throttle body while varying the throttle opening by hand. After you finish, be sure to run the engine for a few minutes.
aaaaad. Tune-Up (services)
aaaaaaaaaai. Valve Adjustment
aaaaaaaaaaii. Timing Belt/Water Pump
aaaaaaaaaaiii. Oil Change
aaaaae. Tune-Up Components (replacement)
aaaaaaaaaai. Distributor Cap, Rotor, Spark Plugs, Plug Wires
aaaaaaaaaaii. Fuel Filter
aaaaaaaaaaiii. Air Filter
aaaaaf. Seafoam
aaaaaaaaaai. Here is the Seafoam procedure that I believe to be correct:
aaaaaaaaaaaaaaa1. Drive to a well-ventilated area. Make sure engine is warm, but leave it on.
aaaaaaaaaaaaaaa2. Find the brake booster vacuum hose. Unplug the hose, and you’ll notice that the idle should now be fluctuating up and down from 1000 to 1800 RPM. You will need a pair of pliers to loosen the hose clamps.
aaaaaaaaaaaaaaa3. Put a funnel into the brake booster hose, and pour the seafoam in SLOWLY so as to NOT let the engine shut off. Pour in only 1/3 of the can. (I will add the exact measurement later). You’ll notice that the engine will try to stay on as you’re pouring it in.
aaaaaaaaaaaaaaa4. Turn the engine off and plug the booster hose back in. Wait 10 to 15 minutes.
aaaaaaaaaaaaaaa5. Restart the engine. The engine will fuss and curse to life – you’ll likely have to floor the throttle to start the car. Blip the throttle in short bursts, revving between 2000-4500RPM. Smoke WILL engulf the general area. I advise wearing a handkerchief over your nose.
aaaaaaaaaaaaaaa6. Eventually, the smoke will subside and return to normal. Drive to ensure everything runs properly.
aaaaaaaaaaaaaaa7. You can additionally add 1/3 of the can to a nearly-full fuel tank, and another 1/3 to your crankcase. If you do the latter, however, PLEASE change your oil within the next tank.
aaaaag. Tire Pressures (contributed by mtnbikaah)
aaaaaaaaaai. The higher the pressure, the lower the rolling resistance of the tires. DO NOT exceed the maximum pressure of the tires; this information will be on the tire sidewall. Realize that you will see more tire wear in the center of the tread, not to mention a stiffer ride.
aaaaah. Low-Rolling Resistance "LRR" Tires
aaaaaaaaaai. Selecting low-rolling-resistance tires can provide up to 5% increased fuel efficiency over sticky summer tires. They tend to have very high treadwear ratings, so they'll last comparatively longer as well. The main downside here, of course, is reduced grip.
aaaaaJ. Check Brakes for Rubbing (contributed by marcusV8thunder)
aaaaaaaaaai. This is something I am not too knowledgeable on. When not maintained for a period of time, the brake pads may end up rubbing against the rotors slightly when the brakes are not applied. This will naturally decrease efficiency. Check your brakes for signs of rubbing.
2. Extensive
aaaaaa. EGR – Exhaust Gas Recirculation
aaaaaaaaaai. http://home.comcast.net/~em-engineering/T2T013.pdf
aaaaaaaaaaii. Cleaning the EGR ports requires destroying the EGR caps currently installed on the engine, so be sure to buy new ones before going into this project. Wed3K did a DIY on installing removable caps so that one can do this procedure easily a second time: http://www.cb7tuner.com/vbb/showthre...ght=ENG%3A+eGR
aaaaab. Transmission Fluid
aaaaaaaaaai. Make sure you have proper Honda MTF or ATF (depending on transmission).
aaaaac. Lightweight Wheels
aaaaaaaaaai. I have in my possession an Excel file with several thousand brands and models of aftermarket/oem wheels with their associated weights. Although the standard OEM EX alloy wheels are fairly aerodynamic and lightweight (15.5lbs), there are other, lighter options out there. I’ll find a way to make this downloadable.
aaaaaaaaaaii. Lightweight wheels will reduce unsprung weight and will reduce rolling resistance a decent amount. The 50-mpg 1992 Honda Civic VX had wheels that weighed less than 10lbs apiece.
aaaaad. Fuel Injector Cleaning
aaaaaaaaaai. Lordoja's step-by-step fuel injector cleaning process thread
aaaaae. Wheel Alignment
aaaaaaaaaai. Improper toe angles can drastically reduce fuel efficiency, not to mention add stress to a car’s structure.
aaaaaf. Weight Reduction
aaaaaaaaaai. This, in my opinion, is something I prefer not to do due to my extensive highway driving. I like the comfort of having sound deadening, a sound system, and seats. If you don’t, remove these items.
aaaaaaaaaaii. Clean your junk out of the trunk! Unnecessary weight can be reduced by simply freeing the car of extraneous items.
aaaaaaaaaaiii. If you must, remove your air conditioner, power steering, cruise control, etc, though this can make driving much more of a chore. You bought an Accord for the space and comfort; I highly doubt you would enjoy removing the sound insulation to save 50 lbs.
__________________________________________________ ________________________________________
Driving Style
It is little-known to non-enthusiasts that one’s driving style is one of the largest factors in fuel efficiency. I will list the techniques I use here, and I hope that other members (notably TheNextEpisode) will contribute here.
1. Avoid jack-rabbit starts.
aaaaaa. Starting off like a sane person will decrease the amount of power the engine has to deliver to get this 3000lb hulk moving. Starting off from a stop is among the harder tasks for an engine, so you’ll want to minimize this as much as possible.
2. Keep your windows and sunroof closed above 45mph.
aaaaaa. You are better off running the air conditioner above 45mph; the air resistance you add by opening the windows/sunroof negates any fuel savings made by keeping the A/C off.
3. Acceleration/Braking
aaaaaa. The killer to fuel efficiency is any form of acceleration and deceleration. Keep a light foot on the throttle and brake, and try to coast as much as traffic permits. On a 45-mph road, accelerate to 45mph and keep it there. Unnecessary slowdowns to 40 will prompt you to reaccelerate to 45 – fuel wasted. Unnecessarily rocketing up to 50 – fuel wasted.
aaaaab. Coast. When you let your foot of the throttle when the car is in gear, ZERO FUEL is used. Upon approaching a red light, I put it in 5th gear* and get off the throttle. The car will slow down early, and in most cases, the light will turn green by the time I get near the stoplight. You won’t need to reaccelerate from 0mph – fuel saved.
aaaaaaaaaai. *If traffic permits, you can downshift to a lower gear when coasting to a stop in order to spend more time coasting and less time waiting at a red light.
4. Highway
aaaaaa. Use cruise control if you’re a beginner. It will teach you how to maintain a constant speed. When cruising at 65mph, you will suddenly notice other cars alternately going faster and slower than you. People normally don’t realize they do this accelerate/decelerate alternating until they use cruise control.
aaaaab. If you are more experienced, accurately apply the throttle to maintain good cruising speeds. 55mph is the best-compromise fuel-efficient speed used in highways all over the world. Drag increases with the square of speed; there is a large amount of drag to overcome from 55 to 65mph, and an even larger one to 75mph.
aaaaac. When approaching uphill overpasses, try to keep the throttle in the same position if traffic permits. The car will slow about 5mph, but once you get to the downhill part, the car should come back up to speed by itself – fuel saved.
aaaaad. Accelerate primarily on downhill stretches. Use gravity to your advantage.
aaaaae. Do not draft (or slipstream) semi trucks. This is extremely dangerous and can piss off other drivers.
5. Bumper-to-Bumper Traffic
aaaaaa. If you’re stuck in stop-and-go traffic, try this: leave a 3-5 car gap between you and the car in front of you. Cruise at a slower speed than the guy in front of you. You’ll notice that when the cars in front come to a stop, you won’t have to! Continue to cruise, even if its 10mph, until you get near the car in front again. You’ll notice that, more than half the time, the car in front will have moved off again. You just saved all the people behind you from that annoying stop-and-go routine. Check this out on youtube; this is a lifesaver especially for manual-transmission drivers.
6. Short-Shifting and Upshifting Early
aaaaaa. Generally, upshifting early in light-to-moderate-acceleration situations will be beneficial to fuel efficiency. This is managed by easing the engine's load when it is highest: accelerating on a highway on-ramp, for example. Upshift so that the revs never get below 1500RPM (to avoid lugging with our old engines). For example, I typically shift at 2200RPM from 4th to 5th gear; the revs drop to around 1600RPM, at which the engine has enough torque to get up to my desired speed without too much effort.
aaaaab. Skip gears under light loads. If there are no cars behind me, I accelerate from a stop in first gear and shift directly into 3rd gear at 2700RPM. Upon hitting 2700RPM in 3rd gear, I shift to 5th gear. The general rule of thumb is to upshift at any time the higher gear will yield you an engine speed of 1500RPM or higher.
__________________________________________________ _________________________________
Feel free to PM me or comment on this thread if you would like your tips added to this list. I WILL give credit to those who contribute. When I feel that the information is thorough enough, I will try to make this a “sticky”.
I spent a lot of time writing this, so I hope it helps.
I’m a genuine nerd; be prepared for a lot of reading. I’ll try and organize this as well as possible.
--
Maintenance
Our cars are now 19 to 22 years old – maintenance is key in keeping a smooth-running, fuel-efficient engine. This list of basic engine maintenance procedures should be able to somewhat maximize the potential of our F-series engines.
1. Basics
aaaaaa. IAC Valve – Idle Air Control Valve (cleaning)
aaaaaaaaaai. http://www.cb7tuner.com/vbb/showthre...hlight=diy+egr
aaaaab. PCV – Positive Crankcase Ventilation (cleaning/replacing)
aaaaaaaaaai. The PCV is located on the valve cover between cylinders #2 and #3. Remove the valve from the valve cover while the car is idling, and place your finger on the hose outlet. If the PCV is functioning properly, you should feel your finger being sucked in with suction. This is the easiest way to test if the PCV is functioning in the F22, but there are other methods you can find online. This is a $3 part that is easily accessed.
aaaaac. Throttle Body (cleaning)
aaaaaaaaaai. Cleaning the throttle body with some carburetor cleaner should free up the gunk left in by two decades of use. With the engine off, remove the intake tube and spray the throttle body while varying the throttle opening by hand. After you finish, be sure to run the engine for a few minutes.
aaaaad. Tune-Up (services)
aaaaaaaaaai. Valve Adjustment
aaaaaaaaaaii. Timing Belt/Water Pump
aaaaaaaaaaiii. Oil Change
aaaaae. Tune-Up Components (replacement)
aaaaaaaaaai. Distributor Cap, Rotor, Spark Plugs, Plug Wires
aaaaaaaaaaii. Fuel Filter
aaaaaaaaaaiii. Air Filter
aaaaaf. Seafoam
aaaaaaaaaai. Here is the Seafoam procedure that I believe to be correct:
aaaaaaaaaaaaaaa1. Drive to a well-ventilated area. Make sure engine is warm, but leave it on.
aaaaaaaaaaaaaaa2. Find the brake booster vacuum hose. Unplug the hose, and you’ll notice that the idle should now be fluctuating up and down from 1000 to 1800 RPM. You will need a pair of pliers to loosen the hose clamps.
aaaaaaaaaaaaaaa3. Put a funnel into the brake booster hose, and pour the seafoam in SLOWLY so as to NOT let the engine shut off. Pour in only 1/3 of the can. (I will add the exact measurement later). You’ll notice that the engine will try to stay on as you’re pouring it in.
aaaaaaaaaaaaaaa4. Turn the engine off and plug the booster hose back in. Wait 10 to 15 minutes.
aaaaaaaaaaaaaaa5. Restart the engine. The engine will fuss and curse to life – you’ll likely have to floor the throttle to start the car. Blip the throttle in short bursts, revving between 2000-4500RPM. Smoke WILL engulf the general area. I advise wearing a handkerchief over your nose.
aaaaaaaaaaaaaaa6. Eventually, the smoke will subside and return to normal. Drive to ensure everything runs properly.
aaaaaaaaaaaaaaa7. You can additionally add 1/3 of the can to a nearly-full fuel tank, and another 1/3 to your crankcase. If you do the latter, however, PLEASE change your oil within the next tank.
aaaaag. Tire Pressures (contributed by mtnbikaah)
aaaaaaaaaai. The higher the pressure, the lower the rolling resistance of the tires. DO NOT exceed the maximum pressure of the tires; this information will be on the tire sidewall. Realize that you will see more tire wear in the center of the tread, not to mention a stiffer ride.
aaaaah. Low-Rolling Resistance "LRR" Tires
aaaaaaaaaai. Selecting low-rolling-resistance tires can provide up to 5% increased fuel efficiency over sticky summer tires. They tend to have very high treadwear ratings, so they'll last comparatively longer as well. The main downside here, of course, is reduced grip.
aaaaaJ. Check Brakes for Rubbing (contributed by marcusV8thunder)
aaaaaaaaaai. This is something I am not too knowledgeable on. When not maintained for a period of time, the brake pads may end up rubbing against the rotors slightly when the brakes are not applied. This will naturally decrease efficiency. Check your brakes for signs of rubbing.
2. Extensive
aaaaaa. EGR – Exhaust Gas Recirculation
aaaaaaaaaai. http://home.comcast.net/~em-engineering/T2T013.pdf
aaaaaaaaaaii. Cleaning the EGR ports requires destroying the EGR caps currently installed on the engine, so be sure to buy new ones before going into this project. Wed3K did a DIY on installing removable caps so that one can do this procedure easily a second time: http://www.cb7tuner.com/vbb/showthre...ght=ENG%3A+eGR
aaaaab. Transmission Fluid
aaaaaaaaaai. Make sure you have proper Honda MTF or ATF (depending on transmission).
aaaaac. Lightweight Wheels
aaaaaaaaaai. I have in my possession an Excel file with several thousand brands and models of aftermarket/oem wheels with their associated weights. Although the standard OEM EX alloy wheels are fairly aerodynamic and lightweight (15.5lbs), there are other, lighter options out there. I’ll find a way to make this downloadable.
aaaaaaaaaaii. Lightweight wheels will reduce unsprung weight and will reduce rolling resistance a decent amount. The 50-mpg 1992 Honda Civic VX had wheels that weighed less than 10lbs apiece.
aaaaad. Fuel Injector Cleaning
aaaaaaaaaai. Lordoja's step-by-step fuel injector cleaning process thread
aaaaae. Wheel Alignment
aaaaaaaaaai. Improper toe angles can drastically reduce fuel efficiency, not to mention add stress to a car’s structure.
aaaaaf. Weight Reduction
aaaaaaaaaai. This, in my opinion, is something I prefer not to do due to my extensive highway driving. I like the comfort of having sound deadening, a sound system, and seats. If you don’t, remove these items.
aaaaaaaaaaii. Clean your junk out of the trunk! Unnecessary weight can be reduced by simply freeing the car of extraneous items.
aaaaaaaaaaiii. If you must, remove your air conditioner, power steering, cruise control, etc, though this can make driving much more of a chore. You bought an Accord for the space and comfort; I highly doubt you would enjoy removing the sound insulation to save 50 lbs.
__________________________________________________ ________________________________________
Driving Style
It is little-known to non-enthusiasts that one’s driving style is one of the largest factors in fuel efficiency. I will list the techniques I use here, and I hope that other members (notably TheNextEpisode) will contribute here.
1. Avoid jack-rabbit starts.
aaaaaa. Starting off like a sane person will decrease the amount of power the engine has to deliver to get this 3000lb hulk moving. Starting off from a stop is among the harder tasks for an engine, so you’ll want to minimize this as much as possible.
2. Keep your windows and sunroof closed above 45mph.
aaaaaa. You are better off running the air conditioner above 45mph; the air resistance you add by opening the windows/sunroof negates any fuel savings made by keeping the A/C off.
3. Acceleration/Braking
aaaaaa. The killer to fuel efficiency is any form of acceleration and deceleration. Keep a light foot on the throttle and brake, and try to coast as much as traffic permits. On a 45-mph road, accelerate to 45mph and keep it there. Unnecessary slowdowns to 40 will prompt you to reaccelerate to 45 – fuel wasted. Unnecessarily rocketing up to 50 – fuel wasted.
aaaaab. Coast. When you let your foot of the throttle when the car is in gear, ZERO FUEL is used. Upon approaching a red light, I put it in 5th gear* and get off the throttle. The car will slow down early, and in most cases, the light will turn green by the time I get near the stoplight. You won’t need to reaccelerate from 0mph – fuel saved.
aaaaaaaaaai. *If traffic permits, you can downshift to a lower gear when coasting to a stop in order to spend more time coasting and less time waiting at a red light.
4. Highway
aaaaaa. Use cruise control if you’re a beginner. It will teach you how to maintain a constant speed. When cruising at 65mph, you will suddenly notice other cars alternately going faster and slower than you. People normally don’t realize they do this accelerate/decelerate alternating until they use cruise control.
aaaaab. If you are more experienced, accurately apply the throttle to maintain good cruising speeds. 55mph is the best-compromise fuel-efficient speed used in highways all over the world. Drag increases with the square of speed; there is a large amount of drag to overcome from 55 to 65mph, and an even larger one to 75mph.
aaaaac. When approaching uphill overpasses, try to keep the throttle in the same position if traffic permits. The car will slow about 5mph, but once you get to the downhill part, the car should come back up to speed by itself – fuel saved.
aaaaad. Accelerate primarily on downhill stretches. Use gravity to your advantage.
aaaaae. Do not draft (or slipstream) semi trucks. This is extremely dangerous and can piss off other drivers.
5. Bumper-to-Bumper Traffic
aaaaaa. If you’re stuck in stop-and-go traffic, try this: leave a 3-5 car gap between you and the car in front of you. Cruise at a slower speed than the guy in front of you. You’ll notice that when the cars in front come to a stop, you won’t have to! Continue to cruise, even if its 10mph, until you get near the car in front again. You’ll notice that, more than half the time, the car in front will have moved off again. You just saved all the people behind you from that annoying stop-and-go routine. Check this out on youtube; this is a lifesaver especially for manual-transmission drivers.
6. Short-Shifting and Upshifting Early
aaaaaa. Generally, upshifting early in light-to-moderate-acceleration situations will be beneficial to fuel efficiency. This is managed by easing the engine's load when it is highest: accelerating on a highway on-ramp, for example. Upshift so that the revs never get below 1500RPM (to avoid lugging with our old engines). For example, I typically shift at 2200RPM from 4th to 5th gear; the revs drop to around 1600RPM, at which the engine has enough torque to get up to my desired speed without too much effort.
aaaaab. Skip gears under light loads. If there are no cars behind me, I accelerate from a stop in first gear and shift directly into 3rd gear at 2700RPM. Upon hitting 2700RPM in 3rd gear, I shift to 5th gear. The general rule of thumb is to upshift at any time the higher gear will yield you an engine speed of 1500RPM or higher.
__________________________________________________ _________________________________
Feel free to PM me or comment on this thread if you would like your tips added to this list. I WILL give credit to those who contribute. When I feel that the information is thorough enough, I will try to make this a “sticky”.
I spent a lot of time writing this, so I hope it helps.
, i also have noted a increase in mpg related threads, this hopefully can make people read first.
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