Sign In Join 



Honda Civic Real World MPG

2058 messages,  Last post on Aug 26, 2009 at 6:19 PM

You are in the Honda Civic Forum. Your Hosts are pat & karens

What is this discussion about? Honda Civic, Fuel Efficiency (MPG)


Messages Page 181 of 206
1
...
178
179
180
181
182
183
184
...
206
Prev
Next
Last
Go To Msg #
Search This Discussion

#1801 of 2058
Re: [bearcrkrd] by mjsten
Sep 12, 2008 (10:01 am)
Reply

Replying to: bearcrkrd (Sep 12, 2008 9:48 am)

Must be a lot of variation car to car... I will try the high octane to see if it makes any dif, but I do the same thing on documenting every fill up every station, cost etc. All this car does is pretty much two and 4 lane highway, and to be honest, I only get about 10% better mileage than my 04 accord.....
Would not have downsized for that type of diference, had I known....
#1802 of 2058
Re: [wai] by pescatore
Sep 12, 2008 (6:39 pm)
Reply

Replying to: wai (Sep 12, 2008 9:59 am)

I think at 600 miles, you should remain calm My worst mileage with my 08 EX 5spd was my first 2 tanks, and I got a little over 32 mpg on both. Then it started climbing. My overall average now at 7100 miles is 35.3 MPG and still climbing, and that's at about a 65/35 hwy/city mix. Considering the EPA combined estimate is 29 MPG, I don't think that is anything to sneeze at. Even better after coming from an '01 RAM 1500 that got 13 overall.
 
My best tank has been 37.5 mpg, and that was mostly highway, under 65 for the most part, with no AC. I can duplicate 37 pretty consistently that way even with a 70/30 mix. All on good old RUL. I honestly don't think higher octane is going to be cost effective for you.
#1803 of 2058
Higher Octane by bearcrkrd
Sep 13, 2008 (9:04 am)
Reply

Replying to: mjsten (Sep 12, 2008 10:01 am)

I use higher Octane on road trips, but not for normal day to day driving. The higher Octane on long trips is just a habit developed from experience. With other cars. Got better mileage on Interstate trips using higher Octane, so stuck with it on this Civic. I use regular, 87 Octane, maybe 85% of the time. Also don't drive with a full load of gear and passengers. That's why I downsized - couldn't justify the gas $$ for just one person, and no, or little, gear.
My brother has an '05 Accord 4 cylinder Automatic, and I remember him smiling about the freeway gas mileage early on, 40+ on some long leg of a journey. Don't know if that has remained constant over time, or if he ever uses higher Octane. I do know he uses full synthetic oil, FWIW.
#1804 of 2058
by sypher
Sep 15, 2008 (5:04 am)
Reply
I'm sure it's been said before but it bears saying, keep track of the type of fuel you are using. If it is an ethanol blend your milage may be between 10-20% LOWER than with a non-ethanol blend. Ethanol fuels dupe the computers in most cars into thinking they are running lean and cause them to make the fuel mixture richer i.e. pump more fuel thus lowering your milage.
 
So if you are getting 29 MPG with an ethanol blend you could possibly increase your mileage to between 31.9 and 34.8 MPG just by switching.
 
Just a thought.
#1805 of 2058
Re: [sypher] by tiff_c
Sep 15, 2008 (8:35 am)
Reply

Replying to: sypher (Sep 15, 2008 5:04 am)

I'm sure it's been said before but it bears saying, keep track of the type of fuel you are using. If it is an ethanol blend your mileage may be between 10-20% LOWER than with a non-ethanol blend.
 
Yes this is true but some states like New Hampshire have mandated 10% ethanol in all the gas sold here. So we don't have a choice. I know I could get better mpg if I was using straight gas. Sadly not an option for us here.
#1806 of 2058
Re: [tiff_c] by oldbob
Sep 15, 2008 (3:09 pm)
Reply

Replying to: tiff_c (Sep 15, 2008 8:35 am)

Ditto NY.
#1807 of 2058
Re: [wai] by izmirian
Sep 15, 2008 (5:29 pm)
Reply

Replying to: wai (Sep 12, 2008 5:16 am)

I just got an 08 EX-AT as well. And 50/50 City/Hwy driving I got around 31 mpg. Is it too low?
#1808 of 2058
Re: [izmirian] by wai
Sep 15, 2008 (6:46 pm)
Reply

Replying to: izmirian (Sep 15, 2008 5:29 pm)

I measure my 650-800 miles mileage on my third fuel fill up which has 3 gallons of 93 Octane, which I still got 31.5 mpg, which is very consistent with my first 650 miles mpg. But on this drive, I drove very aggressively to break in the engine.
I think your mpg is very normal (more or less same as mine). You can experiment by using higher octane gas to see if there is any improvement.
#1809 of 2058
Don't waste money ! by kipk
Sep 16, 2008 (5:21 am)
Reply

Replying to: wai (Sep 15, 2008 6:46 pm)

Did some research in 87 octane vs 92 octane a while back.
Here are the conclusions, based on modern, computer controlled vehicles.
 
There is no more energy in 92 than in 87.
 
If a modern day car is designed to run on 87, there is no advantage to running 92.
 
Higher octane simply means the fuel's ability to reduce the chances of engine "KNOCK" while under stress. Such as towing, heavy loads, red line operation, turbo or super charger applications, and such.
 
Engine ignition "spark" is timed so that the fuel ignition begins when the piston has almost reached or slightly over ridden "TOP DEAD CENTER" of it's travel, and is ready for the "Explosion" that drives it down for it's power stroke. That explosion actually takes place over a period of time. The faster the piston is traveling, the earlier the spark can take place or "LEAD". If the chamber should over heat due to stressfull conditions, that extra heat can contribute to "pre-ignition", where the fuel is totally ignited too early.
 
Under those stressfull conditions, if the engine should knock, the KNOCK SENSOR in the engine will retard the spark timing to compensate.
 
Higher octane has additional additives to help prevent the knock and therefore help to keep the computer from having to retard the spark. Thereby probably helping to achieve slightly better mileage under those stressfull conditions.
 
It gets a bit more complicated than that, but in layman terms that is the story.
 
Bottom line. Under "Normal" conditions use the octane required by the manufacturer. There is no more energy in 92 than in 87. There are more "Anti-Knock" additives in the higher octane fuels. Under all "Normal" driving conditions, the engine computer will deal with the timing.
 
One last thing. The temp gauge in the dash is reading water temperature. It will not indicate, except in rare conditions, the stress in the combustion chamber. So if you hear a "pinging" sound when the engine is under stressfull loads, a higher octane fuel may be in order, even though the temp gauge shows normal.
 
Kip
#1810 of 2058
Re: Don't waste money ! [kipk] by wai
Sep 16, 2008 (5:59 am)
Reply

Replying to: kipk (Sep 16, 2008 5:21 am)

Please clarify me if my reasoning is wrong. The owner's manual said require at least 87 Octane, so it implies that you can use any fuel higher than 87. In this engine, the compression ratio is 10.5:1 which will be more appropriate if you use higher than 87.

Messages Page 181 of 206
1
...
178
179
180
181
182
183
184
...
206
Prev
Next
Last
Go To Msg #
Search This Discussion
To POST a message, please Sign In.

New? Join Now!

Forum Tools

Please sign in.
Email Address:

Password:

Forgot Password?

Search Forums

Enter Keyword(s)

Advanced Search

Browse by Vehicle



View All Vehicles
Advertisement
Ask the Community
See What People Are Asking

Browse by Board

Browse by Topic


View All Topics

Today's Chats

Advertisement