my highway gas mileage experiment

[b.r.i.a.n.]

i was taking a trip to gainesville to pickup my sister this past weekend since she was moving out. i thought it'd be a great opportunity to measure my miles per gallon on the highway.

my gas light was on last saturday night and i pumped 8.38 gallons of gas into my ep3. as soon as i turned on the car i reset trip A to 0 miles. i drove back home and the following morning at 8:45 we departed from miami.

i took pictures as the needle was getting closer to E on the highway.

here's a pic i took at 287.2 miles

http://i35.photobucket.com/albums/d161/iced305/072.jpg


here's a pic i took after i got to 300 miles

http://i35.photobucket.com/albums/d161/iced305/073.jpg

then the gas light came on like a minute or two after the 300 mile picture was taken

http://i35.photobucket.com/albums/d161/iced305/074.jpg

here are some facts:
- k20a2 w/ 6 speed transmission
- basic bolt ons. i/h/e
- tuned on hondata k-pro
- filled up 8.38 gallons after the gas light was already on
- 93 octance gas was used
- it wasn't completely full. it was about one line below the solid line for full
- only one stop was made. i got pulled over my a cop :(
- stops were made at each toll (no sunpass)
- i was going between 70-80 mph the whole way (about 3k-3.5k rpm the whole way)
- only during one occasion did i take the car past 5k rpm
- the a/c was off the entire time. only the fan was used.
- 3 people were in the car. my parents and myself.

if i did the math right, 302.1 miles divided by 8.38 gallons equals out to about
36.05 miles per gallon!

[b.r.i.a.n.]

this is the beginning of my documentation for trip done on the way back to miami on monday.

the gas light came on monday morning as we were headed to my sister's dorm. we pumped exactly 9 gallons of gas. i set trip B to 0 miles as soon as i turned on the car at the gas station.

i took this picture as soon as i turned off the car when we got to my sister's dorm.

http://i35.photobucket.com/albums/d161/iced305/075.jpg

here is a pic i took when the gas indicator reached half way.

http://i35.photobucket.com/albums/d161/iced305/007.jpg

this pic i took when we got to the toll in which you have to turn in your ticket. while i waited in line i snapped a pic.

http://i35.photobucket.com/albums/d161/iced305/009.jpg

and then i took a pic when the gas light came on

http://i35.photobucket.com/albums/d161/iced305/012.jpg

so 308 miles divided by 9 gallons equals about 34.2 miles per gallon.

here are some factors to take into consideration:
- k20a2 w/ 6 speed transmission
- basic bolt ons i/h/e
- tuned on hondata k-pro
- 4 people in the car
- windows up at all times
- no a/c was used at any time. only the fan.
- speed was between 70-80 mph the entire way
- traveling at about 3-3.5k rpm the entire way
- the only stops made were for tolls (no sunpass)
- we were carrying everything in my sisters dorm. amongst the bigger things were here tv and her fridge

in conclusion. we lost about $2 worth of gas due to the extra weight.

[epshtielsl]

Don't use the 8.38 gallons you initially put in to calculate the gas milage. Fill up completely and use that number to calculate. That gas meter/light is inaccurate.

[talonXracer]

You CAN NOT go by what position the fuel gauge is at to determine mileage.

You fill up, zero the trip meter, take your trip then refill the tank. Then you divide the fuel replenished into the miles driven.

[b.r.i.a.n.]

lol i have to redo this then. how many gallons does our tank hold again? iirc it was 13 gallons? someone correct me if i'm wrong

[epshtielsl]

I'm going to drive about 300miles down to VaTech today. I'll post up my findings tonight.

[fierogt]

I get around 250 miles on 10 gal. only city stop and go driving.

[Karma]

lol i have to redo this then. how many gallons does our tank hold again? iirc it was 13 gallons? someone correct me if i'm wrong

13.2 gallons.

do like what talon said.

sometimes the light comes on and off. when the light comes on, reset your B meter and drive an additional 25.

[vbpracer]

Indeed gastank holds 13.2 gallons. I think my light comes on around 10.5 gallons. This is after 320 miles. Than i usually fill up 10.5. But indeed thats how you calculate accurate gas mileage.

[66elwood99]

I figured out mine last week, I am getting 30.0045 miles per gallon. Mixed driving (mainly highway), JRSC'd I/H/E....... pretty good for the way I drive...:mwink:

[matdbom]

i want your motor/tranny set up. i hate revvin at 4/45 k goin 80. i need that six speed like wo

[vbpracer]

I figured out mine last week, I am getting 30.0045 miles per gallon. Mixed driving (mainly highway), JRSC'd I/H/E....... pretty good for the way I drive...:mwink:

Yeah same here, seemed as though gas mileage improved with jrsc.

[jimmyjames]

Tank holds 13.2 gallons but the system holds more. I have had fill ups with over 13 and 14 gallons before.
Here is a receipt from my gas trials back in the day. Notice the 15.098 gallons on the left receipt.
That is a result of driving to really empty and then topping off. So trying to go by the gas gauge or the assumed capacity of the tank will NEVER give you an accurate measure.
I think that the 714.9 written on there was the mileage after these two fill ups thus giving me 27.1 mpg.

http://i30.photobucket.com/albums/c335/jjgarris7/car%20stuff/gasreceiptsmall.jpg

I have another picture somewhere showing me having driven 400 miles or something and still having an 1/8th of a tank. I'll try to find it.

The only real way to measure the gas used is to top off the tank so you can see the gas (simply filling up is ok but not as precise)...of course topping off is not good to do. After that, you drive a distance and then fill up again to topping off to the exact same level as before at the same pump and station. Then you can do the math.

With the JRSC, I have consistently gotten about 30 mpg +/- on the highway at about 70-75 mph average.

[renovator]

out of curiosity i did the same thing last week. gas light came on around 310 miles, filled up, came out to 10.12 and was stupified to learn that i could get roughly 31mpg with my setup and mix'd driving. thats with greddy t618z, RC440's and AEM fuel rail.

[humpmasterflex]

i want your motor/tranny set up. i hate revvin at 4/45 k goin 80. i need that six speed like wo

Word to that! Why doesn't the ep have a 6th gear for cruising?

How are you guys with F/I getting better gas mileage than me... and i'm pretty much stock aside from Injen CAI???

I get 27.5 mpg on average.

My yellow light usually comes on about any 260-280 miles on the tank.... and I usually drive until 320 before I fill up again!

[jimmyjames]

How are you guys with F/I getting better gas mileage than me... and i'm pretty much stock aside from Injen CAI???The shortest/best answer I found comes from Paxton's website:

Fuel economy depends entirely on your driving habits and in some cases you may experience an increase in gas mileage. Under normal freeway driving, for example, the supercharger is not under boost but is increasing the efficiency of the engine by forcing air through restrictions like the air filter.

All it does is make the engine work less to suck air in by itself.

[LAvtec818]

damn 8 gals for 300 miles hmm??

[56chevydan]

Unless I'm missing something, I thought the final drive ratio in top gear in the 5 speed and the 6 speed is the same. Just one more gear in between 1st and 6th in the 6 speed for better acceleration.

Why the interest in this post for a six speed for "cruising" in top gear for better gas mileage??

[jimmyjames]

Unless I'm missing something, I thought the final drive ratio in top gear in the 5 speed and the 6 speed is the same. Just one more gear in between 1st and 6th in the 6 speed for better acceleration.

Why the interest in this post for a six speed for "cruising" in top gear for better gas mileage??
Some people are getting confused with gear ratios.
RSX-S 6th = EP 5th as you said.
TSX 6th gear would be the correct gear to add to a 5 speed for better fuel economy, not the RSX 6th.
Adding an RSX FD of 4.4 instead of keeping the EP's 4.7 would achieve similar results but keep 5 gears. However, unless you have an A2 or F/I, the transmission would be harder to get moving.

[b.r.i.a.n.]

so i pwnd myself with this thread lol.

i'll do another experiment when i take a long road trip.

[koi_killa]

the most i've gotten in recent times was 23mpg. i dont think i beat on my car that much.... traffic for the loss


zee

[shanewdude]

I've been keeping track of every single fill-up since I got the car on a spreadsheet. I also kept one for my previous car... '95 Civic CX (not sure the body code... the little hatch, you know?). Anyway, not too much insight on my EP yet... I will post some averages soon.

On my CX, I noticed that the weather played the largest overall factor in the ranges of my fuel economy. Winter was typically worse than summer. (Snow tires, snow resistance on the road, spinning tires a bit, and colder air) So far, my ep has been far worse than expected. I'm off for summer in 8 more weeks, so I plan to spend some time tuning up and trying to get some better mileage. Bone stock, and I get around 25mpg... I'm envious of those with power mods who still get better mileage! We really need a thread about how to get better mileage through mods.

[epcivicboy08]

Hey guys not sure if this requires a whole new thread...but, i just got my ep3 last week (i will post up pics over the weekend) and i was wondering if you guys can give your estimates as to how many miles can you drive once the gas light comes on. I wasn't sure so i filled up right at the last little line before the end.
by the way, i filled up and so far with 75% highway driving and 25% city driving i was able to get 275 miles. which i believe came out to roughly 25 mpg. i'm on my second fill up so we'll see what results i get this time.

[CastorTroy2]

For some reason today.... i got 150-170 miles on 1/4 tank of gas?? :mbiggrin:

[twisted]

i am getting 33.9 miles to a tank mix driving that is good for me

[koi_killa]

once the light comes on, you can expect to get about 30 miles before you run dry

zee

[slurp812]

Stock 02 EP3. Last tank, I filled up at 336.4 miles, from a previous fill-up. It took 9.811 gallons. That's ~34mpg Its my 3rd tank in a row getting 34 for my normal commuting. I try to get good mileage, not too hard, but I drive real slow, and grandpa like.

[epcivicboy08]

once the light comes on, you can expect to get about 30 miles before you run dry

zee

wow that's pretty impressive. anyone else can add to this?

[jimmyjames]

wow that's pretty impressive. anyone else can add to this?Not true, every vehicle varies. I can go like 40 miles on a light. Regardless, it is a moot point because driving on that low a level causes the fuel pump to be exposed and overheat risking failure.

[slurp812]

Not true, every vehicle varies. I can go like 40 miles on a light. Regardless, it is a moot point because driving on that low a level causes the fuel pump to be exposed and overheat risking failure.

Plus I dont like walking!!!

[PuMpKiN_Ep3]

wow!!! THE BEST I EVER got ... highway/city combined is 31 mpg.... i was driving like a grandpa :mbiggrin: :mbiggrin:

[sittinlow]

i get terribly shitty mileage...

[epcivicboy08]

Not true, every vehicle varies. I can go like 40 miles on a light. Regardless, it is a moot point because driving on that low a level causes the fuel pump to be exposed and overheat risking failure.


I'm sure it does vary, all due to the person's driving style.
but still, to know that you could get at least 20+ miles is good.

[Si_eD]

with over 100k on the odometer, im pretty confident that my light comes on after 10 gallons. so im usually able to get at least 26 mpg * 2 gallons left = 52 miles before i really worry.

and that's underestimating cause i usually get about 28 mpg.

[03silverEP]

i go 75-90 on the light, when i fill up right when the light goes on the EP only takes 9.5 gallons 13.2-9.5= 3.7gal remaining, took it to the dealer and they laughed, typical honda response.... i get 25-27 rarely any better

[MOOGEN]

I get 400 mile per full tank! I did this when I was driving up to norcal alot.

[cHaRL!e]

I get 400 mile per full tank! I did this when I was driving up to norcal alot.

damn thats freaking good.. how much do you usually fill up?

i usually get about 300 when my light turns on. i average about 28mpg

[MOOGEN]

damn thats freaking good.. how much do you usually fill up?

i usually get about 300 when my light turns on. i average about 28mpg

I'm usually about $43.00 give or take to the top. I did this experiment on 87, 89, 91 octane awhile back and I must say the manual is wrong about using 87 octane. Where I live we usually get temperatures up to 100+ and I still got this kinda mileage with 89. Ever since then I never went back to 87 and 91 is just a waste of money unless you have k-pro or something good.

When I was pumping 87's the car felt loss of torque on lower end and when gunning so I assumed that it was taking more gas to make up the difference in octane. With 89 torque is all there and car seems to repect the foot more. On the side note my car is all stock.

[MOOGEN]

It must be the MUGEN Wing! LOL :lol::lol:

[epshtielsl]

I'm back from VaTech, but I was too lazy to take pics of the odo. and pump. I'll calculate my average mpg later...

[todaamann]

the best that i ever got was 37 mpg.. i think i used about 5 gallons or so, but i filled up about 1/4 mile from the highway and drove about 65 the whole way, then filled up and divided the miles by the gallons filled the second time.... i was pretty surprised. plus there were a few stop lights on the highway. but i didn't get on it at all.

[matdbom]

I get 400 mile per full tank! I did this when I was driving up to norcal alot.

do u get towed somewhere in that drive???

[MOOGEN]

do u get towed somewhere in that drive???

LOL...No! if I did i wouldn't be able to tell you my mileage. when i go on the highway i usually balance at 70 mph.

[jimmyjames]

I get 400 mile per full tank! I did this when I was driving up to norcal alot.Word me too. Back and forth from columbus to chicago was about 375 and it can be done easily on one tank.

[Honad]

I highly recommend gasbuddy.com they have an online fuel logbook that keeps the records for you. All you have to do is save your reciepts and populate the information from them.

My 2007 Records for the EP3.

http://farm3.static.flickr.com/2325/2159274518_cd1727655a_o.jpg

[EPandaman29]

i get about 285 usually on a full tank...and its about 11 gallons to fill up after the refill light has been on. i use mobil 1, 91 octane.

[jimmyjames]

Found the one shot I had from my record 35 mpg trip.
The trip odometer was reset prior to this so that is actually 1/8 a tank left after 401 miles. The receipts below the pic are from prior to this trip and then filling up immediately after this picture was taken (topping off the tank both times so I could see gas level).
401.8 miles / 11.277 gallons = 35.63 mpg
No special driving at all but it was mostly all highway miles at around 70 mph (with supercharger).

http://i30.photobucket.com/albums/c335/jjgarris7/car%20stuff/IMG_2531.jpg
http://i30.photobucket.com/albums/c335/jjgarris7/car%20stuff/gasreceiptsmall.jpg

[jjr007]

The low gas light is just a guideline, not a constant, it can go on because you are going up or down a long hill sometimes. most of the time when I have filled up after the light goes on, the tank still had 1 3/4 gallons at least, and 3 gallons at the most.

[socmex7]

I get 400 mile per full tank! I did this when I was driving up to norcal alot.

i did that about 8 time this past school year, and every time i'd get shitty mpg oing up, then ok going down, mybe it was because i'd haul ass up :mangel:.

[bildo16]

does anybody elses gas dummy light seem to be inconsistent? sometimes mine will come and, ill fill up, and it will only take 9 or so gallons. The other day it came on, i pulled into the shop at work and it wouldnt start cause it was empty! I normally average between 28-32 mostly hwy driving.

[shanewdude]

does anybody elses gas dummy light seem to be inconsistent? sometimes mine will come and, ill fill up, and it will only take 9 or so gallons. The other day it came on, i pulled into the shop at work and it wouldnt start cause it was empty! I normally average between 28-32 mostly hwy driving.

Yah, me too. Sometimes it comes on then goes off later on and stays off for a bit.

[jaeguyoon]

does anybody elses gas dummy light seem to be inconsistent? sometimes mine will come and, ill fill up, and it will only take 9 or so gallons. The other day it came on, i pulled into the shop at work and it wouldnt start cause it was empty! I normally average between 28-32 mostly hwy driving.

mine one goes on and goes off and goes on and goes off and stays on finally!

[socalsx]

I got 25mpg last tank. I'm going to drive less aggresive this tank and see what happens. 100% city driving btw..

[epshtielsl]

Sorry for the cellphone pics...
http://i34.photobucket.com/albums/d109/epshtielsl/0506081709.jpg
http://i34.photobucket.com/albums/d109/epshtielsl/0506081713.jpg

Roughly 31 mpg. This was combined highway and city driving, with a few 1st through 3rd wot runs as well as a 4th wot run. So definitely not driving conservatively.

[rolldic]

were you going flat or some uphills?

[slurp812]

I did 360 miles and the light just came on. 10.4 gallons ~34mpg...

[humpmasterflex]

When you guys do the math after the refill.... how much do you refill... until the pump clicks once? Or do you guys fill all the way up to the rim??

[jimmyjames]

When you guys do the math after the refill.... how much do you refill... until the pump clicks once? Or do you guys fill all the way up to the rim??All the way to the rim is the ONLY way to verify the precise level. Any other way, the amount is affected by the fill rate, how the nozzle is held, the pump mechanism, the temperature that day, the altitude....
Of course, topping off is bad to do.

[humpmasterflex]

Man I miss my Ej6 (1999 civic sedan).... they had to go and steal that car!!! FUCKERS!

I used to get 500 miles to the tank REGULARLY... which comes out to be 41mpg of mixed driving.

Now that car was wassup!

[slurp812]

When you guys do the math after the refill.... how much do you refill... until the pump clicks once? Or do you guys fill all the way up to the rim??

first click always. I usually use the same pump at the same gas station also...

[EP3driver]

Sorry for the cellphone pics...
http://i34.photobucket.com/albums/d109/epshtielsl/0506081709.jpg
http://i34.photobucket.com/albums/d109/epshtielsl/0506081713.jpg

Roughly 31 mpg. This was combined highway and city driving, with a few 1st through 3rd wot runs as well as a 4th wot run. So definitely not driving conservatively.


I just got my 2004 EP4 and the first time I got 31.6 mpg. The second time it was just a bit over 30 mpg...I changed the air filter and will drive a bit slower to see if I can get at least 32 mpg. The EG hatch I just sold was getting between 36 and 37 mpg.

[itsanep3]

I don't even want to talk about the horrible gas mileage my car gets, lol. I think it's mainly due to the fact that I can't stay out of boost. :mangel: I'm doing an experiment on my ED6 right now to see what the little d15b2 gets. I'm hoping close to 50 mpg!

[03NighthawkSi]

I figured I would post the results of my own mileage experiment. I wanted to see how much difference driving a little slower made. My daily drive to work is about 33 miles almost all interstate with only 2 or 3 stop lights. I drove 62 mph every day to and from work. Only 1 time did I drive to the post office through town, but that is only about 3 miles. I stopped for gas today at 352.4 miles on the current tank (gas light not even on yet) and put in 10.34 gallons. That comes out to right at 34.0 mpg. I live in the middle of nowwhere pretty much, maybe 62mph may get you run over in some busy places I don't know. It seemed really slow at first but I got used to it. It only added about 5 or 6 minutes each way I think, barely enough to listen to one extra song on the radio. I only have a V2 intake and cat back exhaust as my only real mods.

[thetunersource]

i get 220 miles per tank and im sad

[Hoff]

How big is the 02 ep's tank? I did a long trip this weekend. My yellow light came on around 230-240 miles ish. Filled up with 9.71 gallons. My calculation said I got 29.1 mpg. Does this sound about right? I usually get 210-220 ish with my spirted driving.

[socalsx]

How big is the 02 ep's tank? I did a long trip this weekend. My yellow light came on around 230-240 miles ish. Filled up with 9.71 gallons. My calculation said I got 29.1 mpg. Does this sound about right? I usually get 210-220 ish with my spirted driving.

220 divided by 9.7 = 24/25mpg which is about what i get city driving

[Hoff]

how many gallons in our cars? 9.7 seemed low for a refill. Guessing 10?

[wil524]

how many gallons in our cars? 9.7 seemed low for a refill. Guessing 10?

Me have a 13.2 gallon gas tank.

[humpmasterflex]

I just filled up today.... but I made 366.4 miles on the tank, and the yellow light did not turn on until 318 miles. So I ended up putting 12 gallons in the tank, so I did the math and it came out to be 30.54 MPG... of which is mostly I think none highway driving.

I feel pumped like crazy, because my previous tank was mostly highway miles and my yellow light turned on at about 260 miles, and had to refill before it hit 300 miles. I always come at about 25-27MPG, but hitting 30.5 MPG on the tank really gave me a boost in my confidence with this car.

Then again I cruised controlled on the highway at 60mph, and I shifted at 3.3k every single time! Not once did I take the car above 4k....

So I guess it's not that great, because I used to have an EJ6, and I got an average of 41 MPG doing about 70-80 MPH on a daily basis...... shoot..... I got 30MPG in that car when I was redlining that thing! But with the EP I have to drive like a grandma just to get 30... FOR THE FIRST TIME!

[Honad]

Fwiw guys... it actually takes at least two complete fillups to accurately calculate gas milage.

You fill up once to full, note milage. Fill up again, note milage. The milage you drove between the first and second fill and the gas you put in on the second fill is what you use to calculate your mpg.

I'm telling you. If you want an accurate measurement go to http://www.gasbuddy.com sign up and use their Fuel Logbook feature. It keeps track of all that math for you so that you don't have to pretend. :)

[frm_808]

how many of you drive till that light comes on? i fill at 1/4 tank.

[&REY]

I got 7.1 liter/100km two tanks ago and 7.3 liters previous tank which comes out to 33 and 32 MPG.
First tank i stayed mostly at 62-70mph(100-110kmh) driving on the highway but its way too slow so now i try 110-120kmh to see how much difference it actually makes.

how many of you drive till that light comes on? i fill at 1/4 tank.

light comes on when there is like 10 liters left still(3 gallons) I can still go over 100kms on that, i usually go 50 more kms and then fill up like 44-45 liters



also stupid question:
when you guys do right turn on intersections do u downshift to 2nd or 3rd gear? I find I always downshift to 2nd but sometimes I don't even need to. maybe i can some fuel on that lol

[Honad]

how many of you drive till that light comes on? i fill at 1/4 tank.
I generally fill up right around when the light first comes on... 300 miles or so.

[Oxygen]

Filled up yesterday and got 294.9 miles out of 9.0 gallons (about 32.7 MPG). Not bad methinks. This is mostly highway driving with some city driving.

[humpmasterflex]

how many of you drive till that light comes on? i fill at 1/4 tank.

I drive until the light comes on.... and I drive with the light on for like 50 miles. This past tank the light didn't turn on till 318 miles on the tank, and I didn't fill her up until 366.5.

[03civsi]

I've been watching since the prices have been climbing and I've been averaging high 20's when I beat on it and low 30's when I baby it. Tried drafting for a week and instantly picked up an extra 20 or 30 miles that tank but gave up because it was WAY too dangerous and people were pissy. I also average 70%/30%, hwy/cty. Injen CAI off an RSX-S, MagnaFlow cb, Megan header, 17's, dropped, nothing major beyond that. Noticed the mileage rise with the suspension drop. Was thinking of finding some old school HX wheels or something else that's way lighter then what I have and experimenting with removing excess unsprung weight and also gutting the interior.