whitecat31

(Originally posted in Tech forum with only one person responding.)

Hey all,
I would hope to gain some knowlege from any of you GREAT people who would be so kind as to donate some of your opinions on how to improve my gas mileage.
The reason why I am begging for your advice is my job requires me to do a 150 mile round trip commute a day.
I also hope what is posted here will help others as well, especially with gas being 2.50 a gallon now.

First off, I think I have done a lot of good steps so far.

My car is a 1995 Honda Civic with a D15B7 engine SOHC.
5 speed manual transmission 2 door.
The car has been lowered. (Reduced aerodynamic drag)
The car has an AEM Cold Air intake with filter. (More air)
The car has a REAL loud exhaust. The police love to pull me over for that. Three times already.
I have put in some extra large diameter spark plug wires for that more efficient spark.
I run normal NGK spark plugs.
Car has been lightened with the removal of the power steering. I also don't keep that much junk in my car.
I have 17 inch Katana Rims with 205/40/17 and normal tire pressure. (Not going back to stock)
The car is aligned. I am thinking about doing an autoshops lifetime alignment program though for like 150 with Evan's tires.
I don't use the AC and I tend to drive with the windows up.
Driving style is typical Southern Californian highway driving with a type A personality and a lot of freeway. AKA not Grand Ma. (I know about proper driving style about gas comsumption.. please no lectures.) I am not a speed racer, but I do like to maintain a smooth speed around 80 miles per hour and with about 3600 RPM's.

Ok questions.
First off, what header should I get? A more efficient engine is an engine that won't burn as much gas. I am also sure just removing the current exhaust manifold will save weight.
I want to put in the best header for Gas Mileage. So should I go 4-2-1 or 4-1? Which headers are good for this? What is the best header for a D15B7 engine anyway, and why? I am leaning toward a 4-2-1, but I want a C.A.R.B legal one.
Cost effectiveness is a considering factor.
Second set of questions.
I change my oil monthly because of the commute eating up miles. What weight of oil should I use. I heard light weight oil is better. Is synthetic oil worth the cost ratio in savings for the gas mileage? If I use synthetic oil, what weight of synthetic oil should I use?
Heck. What filter should I use? I use the one that adds teflon.(reduces resistance)
Third Set of Questions.
What spark plugs should I use? Are the Iridiums worth it? Which Iridium plugs should I use? Can I get away with the OBX, or do I have to use the NGK's?
What about the splitfires or quads?

I run 87 octane. I don't think going to 89 or higher octanes would help at all, but I am curious to see the theories.

What about tune ups and valve jobs? Are those necessary when things are going good. How often should they be done?

I am doing an injector cleaner in the morning. Some stuff I picked up with Methanol and some secret ingredient (Octel Starreon)

At some point I will see about changing the fuel filter but would love to see a post or link about that.

Oh yeah. Please don't hate me I already get 36 miles per gallon.

Thank you for any kind advice.

eg4usdm

having a good set of ground wires helps

lighter wheels

removing your rear interior I.E. spare tire, seats carpet and what not

umm about the header i dont know about specs but i would assume 4-2-1 would get better gas mileage, but correct me if im wrong

umm thats all i can think of.. good luck man

y0y0

iTrader: (2)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by whitecat31 &raquo;</TD></TR><TR><TD CLASS="quote">Oh yeah. Please don't hate me I already get 36 miles per gallon.</TD></TR></TABLE>

you're already fine.

whitecat31

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg4usdm &raquo;</TD></TR><TR><TD CLASS="quote">having a good set of ground wires helps

WC: I know next to nothing about ground wires and how to set them up to get better gas mileage and/or horsepower.. How does that work?

lighter wheels.

WC: The Katana Rims are rather light, although I might switch to something else, I just can't justify the cost.

removing your rear interior I.E. spare tire, seats carpet and what not:

D: I would, but who wants to drive 150 miles a day without having a spare.. I will see what I can take out though.


umm about the header i dont know about specs but i would assume 4-2-1 would get better gas mileage, but correct me if im wrong

D: I think you are right, but I am not 100% sure. Anybody know of any C.A.R.B legal 4-2-1 Headers for the D15 engine?

umm thats all i can think of.. good luck man
WC: Thanks.
</TD></TR></TABLE>

teknoracing

Dont use synthetic, your car should run fine on conventional. Use 5w30 cause its getting hot here in so cal. I suppose if it was cooler, you could use 5w20 but its hard to locate. Use the stock NGK plugs.

I suggest using Chevron Techron Fuel injector cleaner and fill up tank COMPLETELY with 91 octane and also clean your electrical connectors.

If youre changing your oil and filter every month, you can get away with using some of the more inexpensive filters like STP or Fram although i dont like fram.

While on the freeway, set it on cruise control to about 65mph-70mph for better gas consumption.

Remove stuff you dont need.

Thats all i can think of.

Bond

Ditch the 17's. Throw on some 13's. Get a valve adjustment. Since you have a 16 valve like me, trust me it will make a difference. Honda adjusted mine and I am seeing better gas mileage. Change the fuel filter to get maximum fuel consumption. 89 octane will just burn a hole in your wallet, 87 is good enough. Pull the A/C for further weight reduction (maybe keep it since you live in Cal.). Remove the spare and back seats. Since your in a warmer state try making your coolent a 70/20 water/anti-freeze mix. Water is lighter then anti-freeze (if you really want to be picky). Also go with a 7lb. flywheel too. If you just ride in your car, remove the pas. side seat. Get a light weight battery and use 10w-30 oil (since you live where it will never get below freezing), because I THINK it's thinner and will not take as long to warm up. Maybe not and correct me if I am wrong. Finally, if you really want good gas mileage then throw a Vx or Cx tranny in there.

wilsel

Let me just say this. If you bought a header for say $200, do you know how long it would take you to save that much in gas if it gave your 1 more mpg?

It would take you almost 500 days of a 150 mile commute if gas is $2.50 a gallon to save the $200 to cover the price of the header. I think your best option is to slow down to 65-70 MPH, and try to draft people.

I have a long commute too, and once thought about getting a civic hybrid. If i got 50MPG vs 35 MPG im getting now. It would take me 10 yrs save enough gas to cover just the price difference between a 2005 civic lx, and a 2005 civic hybrid. I did the math. Then I figure the hybrid technology is still fairly new, and a hybrid car could potentially rack up more maintenance costs than a standard gasoline car.

Falqon

Change your fuel filter if you don't know when was the last time it was changed.

Aside from serious weight reduction, there is nothing that you can do that wil make up for heavy 17" rims, unsprung weighs pwnz joo!

whitecat31

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Falqon &raquo;</TD></TR><TR><TD CLASS="quote">Change your fuel filter if you don't know when was the last time it was changed.

WC: Well, since I am getting 36 miles per gallon, I don't think I have a fuel filter problem, but I guess it is due. So I will look into it. Thank you for the suggestion. Anybody have any links about that?

Aside from serious weight reduction, there is nothing that you can do that wil make up for heavy 17" rims, unsprung weighs pwnz joo! </TD></TR></TABLE>

WC: I don't want to change the tires and rims. They are light weight rims.. Honest.

[QUOTE=wilsel]Let me just say this. If you bought a header for say $200, do you know how long it would take you to save that much in gas if it gave your 1 more mpg?

It would take you almost 500 days of a 150 mile commute if gas is $2.50 a gallon to save the $200 to cover the price of the header. I think your best option is to slow down to 65-70 MPH, and try to draft people.

WC: Drafting is extremely dangerous with the way people drive. They are so distacted with their cell phones and DVD players. I will pass.
It sounds to me, that the header pays for itself, it just takes a while. Besides, should I really need an excuse, to put on a better header? Heck no. I just want to put on the right header.
Anybody know the proper 4-2-1 Header for the D15B7 engine that is CARB(California emissions) legal, and gives the best performance?

[QUOTE=teknoracing]Dont use synthetic, your car should run fine on conventional. Use 5w30 cause its getting hot here in so cal. I suppose if it was cooler, you could use 5w20 but its hard to locate. Use the stock NGK plugs.

WC: Sounds like a plan. I will just change the oil a lot and use light weight oils.

I suggest using Chevron Techron Fuel injector cleaner and fill up tank COMPLETELY with 91 octane and also clean your electrical connectors.

WC: I did a fuel injector cleaner, and I don't think I have any clogs. I checked the electrical connectors. They seem fine, but I cleaned some of them anyway. Thanks for the suggestions.

If youre changing your oil and filter every month, you can get away with using some of the more inexpensive filters like STP or Fram although i dont like fram.

WC: Many people don't like Fram, but I never hear why. I would love to hear it. For now, I guess inexpensive filters and oil, and lots of oil changes will be the rule of thumb. Every 3-4 K miles I guess.

While on the freeway, set it on cruise control to about 65mph-70mph for better gas consumption.

WC: I don't have cruise control, and I can't imagine driving the San Onofre stretch at that slow of a speed with out everybody showing me the number one sign.

QUOTE]

WC: Thanks for the suggestions so far. I would love to hear about ground wires and the proper header.

stormy

02 sensor

cheapest way to get much better gas mileage

whitecat31

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stormy &raquo;</TD></TR><TR><TD CLASS="quote">02 sensor

cheapest way to get much better gas mileage</TD></TR></TABLE>

WC: Stormy? What are you talking about? I think my O2 sensor is fine. I have not seen anything about changing an O2 sensor to help out gas mileage unless the O2 sensor is already bad.
Any links on here with that information?

WC

CrashAndBurn

Keep an eye on your tire pressure. Make sure it's where it should be. If you have the stock rims it would help. It will lighten the load on your car. If you can drive without the windows down it will help you out.

Personally I would find a crx hf to keep low miles on my fun car and get 40 mpg.

mikehawkBUiLT

change your fuel pump, spark plugs, o2 sensor, spark plug wires, hell, do a tune-up and you should notice a big improvement

whitecat31

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mikehawkBUiLT &raquo;</TD></TR><TR><TD CLASS="quote">change your fuel pump, spark plugs, o2 sensor, spark plug wires, hell, do a tune-up and you should notice a big improvement </TD></TR></TABLE>

Well the tune up would include Spark plugs, but I feel my car is already tuned just fine. I thought I also mentioned I had new improved thick spark plug wires. What I want to know is why would I change my fuel pump? Changing my fuel filter I would understand. I think for the effort to change the fuel pump that is still good it, would be expensive and pointless. Please correct me if I am wrong.

WTB CARB Legal 4-2-1 Header from the Souther California area. Prefer OC and San Diego.
Saw some guy in the classifieds selling a Header but could not reply because I am a trial user.
WTB: Some type of high performance Manifold for D15B7 engine.


THANKS for all the SUGGESTIONS so far. I would love to hear about other peoples set ups when it comes to saving GAS and having better HP.

mikehawkBUiLT

oh, woops. i meant fuel filter

lemon_juice

cut holes in your back bumper to the air under your car doesnt get trapped in it. or be a man and just take the entire bumber cover off.

tape up your front bumper too so its slick and smooth, better airflow.

if you can keep your rpm's in the 2500-3200 range, thatll be your optimum mpg.

or catch the buss

whitecat31

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lemon_juice &raquo;</TD></TR><TR><TD CLASS="quote">cut holes in your back bumper to the air under your car doesnt get trapped in it. or be a man and just take the entire bumber cover off.

tape up your front bumper too so its slick and smooth, better airflow.

if you can keep your rpm's in the 2500-3200 range, thatll be your optimum mpg.

or catch the buss</TD></TR></TABLE>

I have a 95 Civic. I don't need to tape up anything because it is already smooth. But that does sound like a good idea, if I had an open grill like the 96 on up Civics. I am not to keen on perforating my back bumper or taking the bumper off. Maybe I could slicktape down on the bottom underside of the car, to somehow stop airflow from hitting the back bumper. That way I could use ugly tape like duct tape.
Thanks for the RPM advice. I will keep that in mind.

WTB CARB Legal 4-2-1 Header from the Souther California area. Prefer OC and San Diego.
Saw some guy in the classifieds selling a Header but could not reply because I am a trial user.
WTB: Some type of high performance Manifold for D15B7 engine.

weedtank

in my experience, when i down shift to a stop it wastes more gas then if i were to just stop with brakes only.

beeboyee

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by weedtank &raquo;</TD></TR><TR><TD CLASS="quote">in my experience, when i down shift to a stop it wastes more gas then if i were to just stop with brakes only. </TD></TR></TABLE>

great first post!!!

hogsnot

If you want to see why lots of people have stopped using FRAM oil filters check out this site.......http://minimopar.knizefamily.net/oilfilterstudy.html

Outrun

The biggest thing you can change is your driving style.

Lowering a car does not automatically reduce drag.

Aftermarket intake may increase fuel consumption if you're not careful.

First, start off with getting your car in good mechanical order. Engine, alignment, tire pressures, etc. A well maintained car will generally be reliable and easier to maintain.

Now, getting back to driving style. Most people do not know how to drive efficiently. They can't hold a steady pace on the freeway. They do not look ahead and anticipate traffic conditions. They speed up and change lanes to get a better position on the street and they don't realize that the car they passed a mile back is right next to them at the next stoplight. Keep this in mind...there was a study conducted that revealed that ambulances only saved about 45 seconds in travel time by speeding through city streets. In an emergency, 45 seconds is a lot of time. But to those regular people in a hurry, it's nothing.

For city driving, drive near the speed limit. From stoplights or stop signs, gently throttle up. You are not on a race track. You do not win any points or prize money for saving a few seconds.

Look ahead. Pretend the bottom half of your windshield is painted black. Look through the top half of your windshield and see what is ahead of you. If there is a stop sign or controlled intersection, let off the throttle. A lot of people stay on the gas and then brake at the end to stop. Just coast to a stop. You don't really use any gas, and if the light turns green you already have some momentum so you don't have to use any more to get back up to speed.

For freeway driving, use cruise control if you have it. Stay at or under the speed limit. The speed limit is there primarily for two reasons.

One reason is for fuel efficiency. Higher speeds need higher gas to maintain the speed and fight aerodynamic drag. Drag increases exponentially.

The second reason is that survivability in a crash is generally greater at lower speeds.

Look ahead. Anticipate slower traffic. Many people get impatient and stomp on the gas to pass a slower car. They navigate through the holes in traffic but sometimes get stuck in a pick (like basketball). The cars they passed previously have now passed the impatient driver.

Because you will be at or near the speed limit, you will generally be slower. Stick to lanes 3 and 4. When approaching a slower car, begin your lane change earlier. Many people get to within a few feet of the car. They slow down before making the lane change. If you begin your lane change earlier, you won't have to change your speed.

Through it all you have to be smooth with your steering and throttle inputs. The same techniques used to be fast in a racecar are the same techniques used to be fuel efficient on the street. You have to conserve momentum. I think this technique is also taught to fighter pilots, as it is harder for a plane to regain lost speed.

I average 22,000 miles a year. I have 223,xxx miles on my D16Z6 Civic. From experience, my Iceman CAI, DC ceramic header, and GReddy exhaust made no significant difference when driving normally. On the track, they helped make more power, but that in turn required more fuel.

My extreme fuel economies was 11.7mpg during a day of hotlapping at Streets of Willow Springs and 42mpg driving 55mph hanging out with big rigs on the freeway. I typically drive between 65-70 (speed limit is 65 in most places in SoCal) and get 38-40mpg.

Outrun

PS: I use ARCO 87 almost exclusively and use regular 5w30 oil (Pennzoil, Castrol, Quaker State, etc whatever WalMart has at the time).

Also, taking care of the little bits like holes in the bumper, etc. won't produce significant results. Otherwise, the car company would've designed it like that.

It's probably a common misconception that's similar to truck drivers driving with the tailgates down. They think a lowered tailgate reduces drag, but in fact it increases drag over a closed tailgate.

So to all you truck drivers out there, keep those tailgates closed!

Purple_Civic

MORE GAS MORE POWER!!! THAT WHAT I SAID

GSX TO CX

The vx/cx tranny would make the biggest improvement. It would bring down your rpm's significantly. On my cx the gearing is 30 mph per 1000 rpm in top gear which means if you drove 90mph you would only be turning 3000rpms. An underdrive pulley should probably help also be reducing parasitic drag. Otherwise most of the replies have been right on. Drive slower keep a constant speed and try a valve lash adjustment. I averaged about 2 mpg better after mine, now averaging 41 mpg in the cx.

whitecat31

I guess I should repeat these questions.

First off, what header should I get? A more efficient engine is an engine that won't burn as much gas. I am also sure just removing the current exhaust manifold will save weight.
I want to put in the best header for Gas Mileage. So should I go 4-2-1 or 4-1? Which headers are good for this? What is the best header for a D15B7 engine anyway, and why? I am leaning toward a 4-2-1, but I want a C.A.R.B legal one.
Cost effectiveness is a considering factor.
Second set of questions.
I change my oil monthly because of the commute eating up miles. What weight of oil should I use. I heard light weight oil is better. Is synthetic oil worth the cost ratio in savings for the gas mileage? If I use synthetic oil, what weight of synthetic oil should I use?
Heck. What filter should I use? I use the one that adds teflon.(reduces resistance)
Third Set of Questions.
What spark plugs should I use? Are the Iridiums worth it? Which Iridium plugs should I use? Can I get away with the OBX, or do I have to use the NGK's?
What about the splitfires or quads?


WTB A CARB legal perfomance Header from the Socal area. AKA I want to pick it up.