2007 Civic Coupe Auto EX Gas Mileage Decline!!??

gn3ric · 09-22-2008

Quote:

Originally Posted by gearbox

alot of people arent too happy with the newer civics mileage. not sure if its only some cars, but ive heard that even some newer hybrids were only getting 26 mpg. but most of it comes down to where you live and how you drive. that link you posted is not that impressive either, thats what most civics from 0 yrs ago were still getting. full synthetic isnt the best idea either. i used to get 32-34 mpg in illinois (sea level, flat roads) using regular dino oil in my 02 civic with mods.

Something wrong with my civic then

but that's weird.. i'm so confused..

BJanzen · 09-22-2008

Did the gas mileage go down when you got the K&N filter? They let in alot more air then the OEM Filters do. More air let in = more gas used. Just a thought. Dont know how you lose power in that scenario.

gearbox · 09-22-2008

most of the time, the stock airbox can provide more than enough air for the engine. and when you replace it with a short ram, it draws hotter air from the bay, and the pipe itself gets hotter and warms air to some degree. hotter air = less oxygen = ecu adding less fuel to obtain correct a/f mix. thats why you get such terrible mileage in the winter but the car feels more powerful. but again it depends on how you drive. driving a full tank below 3k rpms got me 34mpg. driving below 4k rpms gave me 22 mpg. and driving the car hard above 5k rpm got me 15mpg. driving constant highway usually gets me around 40mpg. again, if you keep your car in good shape, it all comes down to driving habits. when my car was stock, i could barely get 36-38 mpg on the highway. with i/h/e mods, i get 40+ mpg on highway. just think of it this way. the more you press the accelerator, the more gas gets used.

krazymatt · 09-22-2008

I got my car used with 8k miles this past May. The day I got it; I changed the oil because it looked dirty and replaced the air filter with a K&N because it was filthy. The 34-36mpg I got was after that--then the decline was just recently within the last month. Matter of fact we took it on a road trip to Vegas 600+ miles one way in June and it was getting 32-33mpg and I was running it 75-85. I did notice sporatic changes in gas mileage using Sams Club gas. I even got like 43 mpg on one tank all of the sudden on the same commute to work. I couldn't understand it. I still can't I guess. I have a strong feeling the gas and all the additives they put in it make the world of difference. At times the additives might not be mixed right and you get into the good part of the storage tanks or the bad part. I have a feeling Sams and Costco do cut the gas with stuff in order to be able to sell it 15-30 cents cheaper. This stuff either evaporates or just burns inefficiently.

gearbox · 09-22-2008

get the stuff in my sig it will make any gas good

swett2k6 · 09-25-2008

i have a 06 civic coupe thats killing me with gas mileage. i did an oil change i put castrol 10 30, i then full my tank then gas light came on after 189 miles. it recommends 5w 20. can oil make a big diff in gas mileage? there's no check light on. i did a diagnostic tes and everything is perfect they say

krazymatt · 09-25-2008

I would stick to 5w20. I'm not sure if the 10w30 would make that much of a difference, but it is somewhat thicker and it has to affect it some. 189 miles and the fuel light came on???!!! That's pretty bad for a Civic! It seems like mine is doing better, I'll fill up today and find out if it surpassed the 31mpg. It might, I have like over 325 miles and it still has about 1/4 tank. It seems to be doing slightly better every tank of Shell gas instead of Sams. I think I'll get a fuel injector cleaner. Sometimes when it's idling cold it's a little rough.

krazymatt · 09-25-2008

Okay, Finally tanked up and I calculated just under 32mpg. I'll admit I had been pushing the car to and from work on the hills. About half this last tank I slowed down. A sherriff clocked me 80 on a 65 a few days back

so I did slow down--especially after he just gave me a verbal break! If that's not a sign I don't know what is! So from here on out I'm really trying to make it a point to slow down at least 10mph and try to keep the RPM's 3k and below. Hopefully in another month or so when I change the oil and throw in a fuel injector cleaner I can get it back to at least 34 mpg.

swett2k6 · 09-25-2008

well i did my oil change today. gonna full up when i'm goin to work tomorro with shell so i'll see the results. one more thing. here in jamaica we only have 87 and 90. the dealer told mi to use 87.

krazymatt · 09-26-2008

Swet2k6, Wow! I hadn't noticed you're in Jamaica! I'm envious! I can already see those turquoise-blue waters!

I would think it would be easier for you to get a little better mpg's than me being that you're at sea level. I'm at 6k to 7k above sea level with a few steep hills I have to negoitiate every day on my commute to work.

gearbox · 09-26-2008

32 mpg is pretty good actually. and yeah stick with 87

swett2k6 · 09-26-2008

i need to lower my car. what springs or coil overs u recommend. i want it to be low as a snakes belly

gn3ric · 09-27-2008

Quote:

Originally Posted by krazymatt

Okay, Finally tanked up and I calculated just under 32mpg. I'll admit I had been pushing the car to and from work on the hills. About half this last tank I slowed down. A sherriff clocked me 80 on a 65 a few days back

so I did slow down--especially after he just gave me a verbal break! If that's not a sign I don't know what is! So from here on out I'm really trying to make it a point to slow down at least 10mph and try to keep the RPM's 3k and below. Hopefully in another month or so when I change the oil and throw in a fuel injector cleaner I can get it back to at least 34 mpg.

goood stuff matt. I'm gonna be filling up pretty soon probably in a day or two before Monday. I'm gonna go for Cheveron 87 octane. I've been using Costco gas for quite a while now. I wanna see if it makes a difference. I'm gonna try to dedicate myself to driving below 3k and grandma it and see what happens. The thing is.. sometimes you have to push it a bit over 3k cause passing people on freeway with civic is not fun

take it easy.

mdawg · 09-27-2008

Im driving an older civic but Shell seems to result in the best mpg for me. I avg 31 on my daily commute to and back but im normally doing 75-80 the way there. I live in the a very mountainous region so my city is around 28. Funny how my Y7 with 109 hp gets worse mpg than some of the turbo'd people on here.

gn3ric · 10-08-2008

Ok guys, I did what most people would recommend by keeping it below 3k rpm and i got the car to shift mostly at 2.5k. I pumped on 9/28 and just pumped today 10/7. On 9/28(Sunday) i pumped 10.33 gal when i had 1 bar left with the light on and today(10/7) i pumped 10.44gal with no bars left :X. I calculated and i only got 30mpg or 30.5559 etc if you want to get complicated. I mostly go to school and on average i travel 30miles a day or sometimes 40 depending if i have errands or not. So... what do you guys think? Is this bad or bad... ii read on some other forum that our tanks carry 13.2 gal? true or not? I pumped today with no bars left and light on and did NOT top off and let the pump stop on its own at 10.44 gal (FULL) So my tank lasted me 1week and 2 days traveling everyday.