Honda Civic Real World MPG

kork13

Took a 300 mile round trip over the last couple days, up into the mountains of central Colorado. What impressed me was that in spite of the 9000+ foot altitude, 3 people in the car, and weekend bags in the trunk, I still got 34 mpg in my Si. That also included me having to constantly switch between 5th and 6th gears to keep moving up the mountains, because of the speed limit being between gears, and my car being quite heavily loaded...

So yea, I continue to be impressed with my car, in both performance and mileage. On the highway, I average between 34-36, in town between 28-31. And this from a car EPA rated for 23/32! And yet, when I kick it into lower gears and let the tach fly up to 7000+, every second is a joy.

ruking1

"While the range remains the same-38-42 mpg, we have been getting more tank fulls at 41/42/43 mpg!!! "...

Still trucking! Car is approaching 50,000 miles. Same ole same old commute (27 miles each way, 40 min to 1.5 hour commute). Trend is up! The last 2-3 tank fulls at 41 mpg. (actual 41.111) 10,000 miles on the OCI, 10,000 miles left on this OCI. 35 psi on the oem tires.

jefferyg

On a 250 mile trip from Birmingham, AL to Hattiesburg, MS - all interstate except about 15 miles running around in Tuscaloosa - I got 36.5 mpg. I was running around 75 mph on the interstate with the A/C on the whole time.

Again I say I can't wait for cooler weather to see what the car can do with the A/C off. At least it's averaging better than the 2008 ratings. 27 is the worst I've ever recorded and that was all local driving.

Kork, you make me sick. :mad: :sick: I looked at and even test drove an Si and the salesman told me most customers were getting better than the numbers posted on the sticker. But my wife just can't stand a manual transmission. The only thing I didn't really like was the black interior. Actually, I should say I love the looks, but hate the upkeep. I've got a 7 and an 8 year old and black is so hard to keep clean.

jefferyg

I went back and read your previous post again and I'm not sure I follow your logic. I checked my car again and indeed at 2000 rpm in 5th gear the car is going 61 mph on level ground. At 2500 rpm it will go 77 in 5th gear.

If your car is running only 47 mph in 5th at 2000 rpm and 58 mph at 2500, then your car should be getting much worse gas mileage than mine with the automatic.

Perhaps the altitude makes a difference. Maybe it's running the A/C ALL THE TIME here. I don't know. :confuse:

damocles

I just bought an EX sedan automatic a few weeks ago, and on my first tank of gas, I got 17.6 mpg, with 95 % city driving (San Francisco). I never used the AC, and I drove fairly conservatively. I can only assume that all you people who get crazy high mpg don't live in big cities.

I'm not surprised at the low mpg I am getting either as I was already told by Consumer Reports that the Civic only gets 18 mpg city. Consumer Reports gave the civic a 18/43/28 mpg for city, highway, overall, respectively. Seems to me like Consumer Reports has it pretty accurate.

k5ldb

Based on the crazy hills they show in the movies I'd say that's a much larger factor for S.F. than being a city. I hope to visit before I die and see it in person.

civicdave

Thanks for the feedback. Other than MPG, I really like the car. It's an absolute pleasure to drive. It does seem to "coast" really well on its own momentum - something I need to adjust to. I am only concerned about the MPG as others seems to be achieving mid 30s. One of my buying criteria was a car that gets at least 30 MPG , but closer to 35 MPG. After a couple of more tankfuls, I'll post more results.

backy

35 is realistic if you do mostly highway driving, or suburban driving with few stops. Good luck!

whitewolf

If you are relying on the "first" tank of gas provided by the dealer, the tank wasn't full. The gauge might have read full but I'll bet you were missing a gallon or two. Mine will stay on the full mark for about 100 miles before it starts going down (about 3 gals). Wait for your second or third tank to get the true gas mileage.

eldaino

totally agree with whitewolf, they usually don't fill it up all the way, it just looks like it.

damocles: i dunno about consumer reports but a car that gets 19mpg in the city cant have an engine that is so extreme that it also gets 43 on the highway.

recalculate your mpg on the next tank. there is no way you are getting that low, i averaged higher in my bloodthirsty vw rabbit!

backy

Keep in mind CR's testing grounds is on the outskirts of NYC. So to them, "city driving" may mean driving around NYC--a pretty extreme test, for which 19 mpg might be pretty darn good.

jefferyg

Mine will stay on the full mark for about 100 miles before it starts going down (about 3 gals).

I've only had one tank that went more than 50 without the fuel gauge coming off the full mark. If you're getting 100 I'm guessing you're packing the tank. That is not a good idea on your new Civic or almost any other newer vehicle as it can lead to problems with your emissions equipment.

But I do agree with you that you should never rely on the first tank from the dealer. Furthermore, 17 in a Honda Civic is ludicrous - anywhere! The thing to remember is that if you come back to the place you started from you had to go downhill the same amount as uphill. Yes, you're pulling some big hills in San Fran, but you also get to coast down them.

I would think that brakes would be your high maintenance item there.

shipo

Folks, please remember that all Honda VTEC engines are really two engines in one. Keeping the RPMs down below something just over the 3000 RPM mark (I don't remember the exact point) will keep your engine in economy mode, however, step over that mark with frequent acceleration blasts in a stop and go urban environment and your mileage can easily head south of 20 mpg.

Best Regards,
Shipo

kenlw

approximately 10k on 07 AT EX Cp:

27.8 mpg

conditions: daily driver in Houston freeway traffic. Stop and go "highway" and bursts to 85mph+ at times to pass idiots, NEVER more than a few minutes of steady speed, at ANY steady speed. Not too much "street-level" (30-35mph) driving, I use the highways and tollways a lot....commute is 31 miles one-way, 62 miles R-T daily.

Using whatever brand of gas is on sale.

95%+ with AC on. Also 18" HFP kit (extra wide tires).

Since I consider this "city" driving, and the advertised value was 30mpg, I'm ok with it.

Steady state speed-limit mindful "maxing the mileage" driving just isn't in the game book for me.

kipk

we have to pay! :sick:

whitewolf

I don't think that I'm overfilling the tank, I have filled the tank the same way on my 97 jeep grand cherokee, 06 civic, and 07 civic with no ill effects on any car. The 06 civic also got about 100 miles before going off full. I thought this was normal. Anyone out there care to comment about when your car goes off the full mark??

ruking1

I generally fuel to the first click and be done with it. It is true that if you overfill, you can damage the emissions system. To keep that from happening would imply that you know a bit more about the technical aspect. Too much to remember for multiple vehicles. :confuse:

jefferyg

I learned the hard way on a couple of vehicles I've owned. They were like babies - put a little too much in and they would spit it back out at you. :surprise:

Then again I've had a couple of older models (Fords mostly) that seemed to never get full. No matter how many times you squeezed the trigger you could always get a little bit more in it.

harvey44

Every car we've had in the last 15 years (5 cars) has told me not to top off or overfill.

There must be a reason - what would be the motivation for BSing on that?

ruking1

A lot has to do with the expansion/contraction of the fuel during operation and ambient temperature changes (deltas). So it seems to me to best let the systems do their jobs. I have read in passing it can be as much as 50%. I have no links for the exact %/'s. Also I have read it is best to get unleaded fuel duing the cool of the day vs the heat of the day for that very reason.

ruking1

Yes I hear you! It also it getting more costly if one takes the car into the dealers'. Just to read codes cost a min of 75. at some places.

k5ldb

Like a lot of things fuel will expand as temps rise so you get more bang, or in this case octane, for your buck if you buy in the morning when it's had a chance to cool overnight. That expansion is another reason they say don't overfill. If I know I'm going to drive far enough to burn a gallon or two I'll squeeze in more since I know it's about to go anyway. If I'm just filling and going home, like after a round of store, post office, bank errands. I usually go once after the first click and at the second click off I stop.

ruking1

If managed correctly, the only real variable we are practically affecting is the RANGE @ mpg of the gals you over fill. My take is why use brain cells when you dont over fill, the system is designed to do it automatically/seamlessly.

blufz1

Has the morning fill vs the evening fill been quantified in percentages? Thanks.

k5ldb

I don't know if there's specific percentage information however there is a lot of controversy over this in the trucking community where purchases of 100+ gallons every day or two is the norm.

blufz1

Thanks,man.

kiawah

Tanks underground are about 55 degrees. It's not going to matter very much what time of day you pump it. How soon after the station gets a delivery would be a larger variable, I believe.

targettuning

The reason for not overfilling (assuming no one has touched on it) is that the evaporative canister that collects fuel vapors and returns them to the tank at regular intervals has a return valve near the top of the filler neck. If this valve is under water (fuel)when the command to open the valve for vapor to return to the tank occurs raw fuel will back flow into the cansiter. This will log a code, the check engine lamp will illuminate,and the vapor canister may need replaced. These are all possible and not worth the effort to squeeze in an extra 1/2 gallon. Remember the fuel system is now a closed loop.

jefferyg

Thank you for the explanation!!!

eldaino

on the newer i-vtec engines, the lower rpm profiles are not as drastic in their cutover as the older ones where, where a specific rpm range was needed to be met before you would be in the 'high output' cams. i vtec smooths this over so that the changes are less apparent and brash, and it switches over to the higher cam profiles in a step fashion.

but at anyrate, i used to floor my civic all the time with relatively no harm to mpg. i mean, they werent the best tanks or anything, but it wasn't like 'oh man i can never floor it or keep it over a certain rpm range!'.

vtec has nothing to do with it; if anything its HELPING the r18 get better numbers, not worse ones. ANY car can have their mpg lowered by frequent blasts of acceleration in those sort of conditions.

ruking1

Another discussion point. I also follow on the Honda Civic (actually, all my cars) the concept of getting to so called cruising speed as soon as possible (briskly). I do not accelerate slowly to that point, unless road conditions warrant (slow acceleration). I continue to get the mpg posted in other posts.

ruking1

For those folks who do fill way past first click off, it might be instructive to get a price for parts and labor to fix and/or replace the evaporative canister after a code is triggered.

kork13

My argument would just be that you're still buying that extra quarter gallon, and unless you're planning on driving through a region where you won't see a station for hundreds of miles, there's no reason to overfill it. It's not like you get any 'bonus' out of doing it.

eldaino

how much is way past the first click off? if i fill up and its like 24 bucks and some change, i'll usually top it off until the dollar amount is even. (25) is that a lot?

kork13: well, given that the extra fuel from that top off could possibly give you some extra miles, it would affect your calculations on how many mpg you are averaging.

ruking1

Indeed, the dollar amount is NOT the issue, despite it being a real consumer short hand. Gallons or more arcanely %'s (or fractions there of) ARE!

Again the MPG calculation can be affected by the consistency (or lack there of) of HOW it is fueled. So for example, if you fill it way past first click and then fill it the next tankful AT first click, THAT variable will affect the calculation. Further examples of complications: what is the deviance between the on board computer and the actual tank. The implication should be obvious here!?

blufz1

Thanks,man.

shipo

Obviously I cannot speak from personal experience, however, after spending time on other 8th generation Civic boards, "staying out of vtec mode" is considered to be almost a given criteria for good gas mileage.

Best Regards,
Shipo

ras314

Over 3805 miles the 2007 manual LX coupe used 92.1 gal for an average of 41.3 mpg. Worse tank was 34.8 with a lot of city driving, best 47.5 mpg with 60 miles of strong tail wind on 55 mph roads. Actual miles was slightly higher as the odometer reads almost 1% low. 34 psi in the tires.

Using the ScanGaugeII it is easy to see avg milage drop to low 30's in stop and go city driving. Interstate milage can really drop with speed and headwind, on one several hour stretch at 70 mph milage dropped to around 30 then increased about 37 as the wind died. It was also surprising to me to watch milage change for no other apparent change than road surface roughness.

There just seems to be too many variables for anything other than long term records to keep up with real world MPG. I think I can claim 40 mpg avg and am quite pleased with that. All city use would likely be around 35 or less.

kenlw

ras314 said:
"There just seems to be too many variables for anything other than long term records to keep up with real world MPG. "

someone gets it.....tracking mileage on a tank-to-tank basis is prit'near useless.

ruking1

And to think there are those who fervently in Congress and represented by Congress who want to pass 35 mpg legislation!

jefferyg

Great post!

One variable that does seem to make a difference across the board is that you guys who have 5 speeds seem to be doing better on average than those of us with automatics. I'd love to see someone like Popular Mechanics do a real world test of several vehicles with A/T vs M/T in identical conditions.

If the Civic with M/T showed consistently 5 mpg better than the A/T, I'd be inclined to tell my wife she'll just have to get used to driving with both feet. We had a '90 Accord with a 5-speed, but she didn't like it. She once let it roll back under a Mimosa tree in our front yard and I had to get it out for her, and on another occasion she had trouble getting out of a parking lot that went up a grade. It was traded shortly after the parking lot incident.

kenlw

It normally makes sense that the mt does better mpg-wise, but the EPA ratings show the at with slightly better mpg....go figure.

targettuning

Yes, for reasons I don't quite understand the manual transmission version of the 8th gen Civic seems to get better fuel economy (according to users who post those sorts of things) than the automatic even though the manual in top gear (5th) at highway speeds runs more than a few hundred RPM's faster than the auto in top gear (also 5th) at the same speed. So, while the auto is more relaxed running less than 2500 RPM @ 70 mph and if I remember correctly (and if I don't someone with a manual will correct me) the manual is over 3000 RPM at the same speed the manual still manages to get better economy???

ras314

Actually I am having trouble getting used to the manual as I am not used to the low torque high rpm engine. Hate to admit how often I've either killed or over revved it leaving stop lights. For city use, especially if hilly, I wouldn't pick the manual just for some possible mileage improvement.

In my post above, of the 3800 miles only 2400 was on the trip. Actually trip milage was slightly less than before, probably because of higher speeds and more city driving.

ruking1

If you follow any of the so called performance threads, the basic dyno runs (called pulls) gives the figures in a very unambiguous way. Bottom line; automatics have app 20% drive train WASTE vs app 11% waste for a 5/6 speed. Of course it is simple to calculate the difference just by the EPA auto vs manual numbers. As alluded in other posts, there are of course different and similar variable between the two transmission choices.

Strictly from an EPA ratings point of view, the Honda oem seems to have mated the dynamics better for the automatic than other oems.

k5ldb

[i]tracking mileage on a tank-to-tank basis is prit'near useless.[/i]

I use trip A for tank to tank mainly for fun and trip B to accumulate about a half dozen tankfuls to do a more realistic calculation with.

ras314

Simplest way for me to keep track is write the odometer miles on the gas receipt, then keep records in a spreadsheet. Usually add a few notes on type of driving conditions along with ScanGauge readings now that I have one.

Probably won't be as careful after the car is a year or so old.

eldaino

gotcha. however, on the 8thgen civic forums, many folks STILL don't get how ivtec works, thus anyone who says they drive their new civic 'out of vtec mode' has no idea what he she are talking about, as i vtec is always 'activated' throughout the rpm range.

and this vtec is economy vtec; its not the same application as it is on the kseries engines, where the vtec is used to extract maximum power, and thus why fuel economy lags.

ruking1

Still got 40.9 mpg. Three drivers, 3 day daily commute, 200 mile R/T with A/C blasting going 65 to 85 mph in the SLOW lanes, 1 hour in full (freeway) rush hour, fueled in 90 degree temps, no real attempt at fuel miser driving...

kipk

The VTEC is always there, in VTEC engines. It is part of the engine parts and pieces, as such. Think of it like the radio volume is always there. We can control the "Volume" low or high.

In normal driving, the "VTEC", is operating in economy mode. Intake valves are riding on individual cam lobes and opening an amount that encourages smoother performance and better economy at lower RPM. As we "Turn up the Volume" by giving more throttle and encourage more RPM, the oil pressure rises and the "VTEC" becomes operational in a more aggressive mode. The valve rocker arm operations are "PINNED" together, a third cam lobe then opens them more, and more power is produced. This encourages better performance, at the cost of fuel economy.

"The new approach was to regulate valve operation to optimize performance at all engine speeds: opening the valves a small amount at low engine speeds, opening the valves wider as engine speed increases. That’s the breakthrough we named VTEC".

http://world.honda.com/automobile-technology/VTEC/

Thanks,
Kip