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Ok... so here's a real stupid one on my part. Over the past 4-5 fill ups, I've been getting horrible gas mileage on my '14 sedan - on the order of 25.6 mpg. I drive short, 4.5 mile trips to and from work 5 days a week. Been driving with ECON ON. Typical winter driving in the Pittsburgh area with outside temps in the 10-30˚ range. Running regular through it from a local station. Only 13.5k on the vehicle. What am I doing wrong? Should I be running with ECON OFF? Should I go with premium fuel? Seems like a waste for limited driving but this current low MPG return is bugging the living daylights out of me. I got these kinds of numbers on my '01 Accord up until I got into this '14 sedan. Stumped right now.
When trying to solve a problem such as this, you have to know where and how you started, for a baseline, and then change only one variable at a time. Otherwise you won't results that mean anything because you won't know what the actual factor was that caused any change.
 

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When trying to solve a problem such as this, you have to know where and how you started, for a baseline, and then change only one variable at a time. Otherwise you won't results that mean anything because you won't know what the actual factor was that caused any change.
Thanks for that bit of helpful info Scotty but gee... yeah, I kinda already knew I'd have to do that... going about it semi-scientifically, that is - changing one variable at a time - it's called the scientific method of inquiry.

I guess my point is... I haven't changed anything about my driving or car-care habits. Same driving pattern. Same fuel procurement. Same locations. I haven't changed anything on my end. No fuel leaks on the ground. No odor of gasoline either in the garage or around where I park the vehicle. The only thing that's changed has been the winter weather - with snowfall and lowered temps.

And before you jump to the conclusion, NO, I don't let my car idle either in the morning (I work overnight shifts) or at night before coming to work, to bring it "up to operating/interior temperature". I usually just get in, start it up, wait 'till the dashboard display clears, wait maybe 15-20 seconds (look at the second hand on a clock - it's plenty of time) and then drive off.
 

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Truck? What truck?!
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Thanks for that bit of helpful info Scotty but gee... yeah, I kinda already knew I'd have to do that... going about it semi-scientifically, that is - changing one variable at a time - it's called the scientific method of inquiry.

I guess my point is... I haven't changed anything about my driving or car-care habits. Same driving pattern. Same fuel procurement. Same locations. I haven't changed anything on my end. No fuel leaks on the ground. No odor of gasoline either in the garage or around where I park the vehicle. The only thing that's changed has been the winter weather - with snowfall and lowered temps.

And before you jump to the conclusion, NO, I don't let my car idle either in the morning (I work overnight shifts) or at night before coming to work, to bring it "up to operating/interior temperature". I usually just get in, start it up, wait 'till the dashboard display clears, wait maybe 15-20 seconds (look at the second hand on a clock - it's plenty of time) and then drive off.
It's good that you know of the scientific method, but there was no way for me to know that. A lot of people don't. I was just trying to help you avoid chasing your tail, so to speak. I don't jump to conclusions.

But good luck solving your issue.
 

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It's good that you know of the scientific method, but there was no way for me to know that. A lot of people don't. I was just trying to help you avoid chasing your tail, so to speak. I don't jump to conclusions.

But good luck solving your issue.
Sorry if that sounded a bit smarmy on my part but I thought that, with 25k+ posts on your part, you might have already figured out that that's what I'd end up doing.
 

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Discussion Starter #85
So your doing the opposite of me but you have short trips right? Which is great. My fuelly is with both on so I already have numbers.

I know there is a advantage for both but I am trying to figure that out. Turning them off and on when conditions warrant them for the best mpg. Datalogging would sure help make this easier.
Ok... so here's a real stupid one on my part. Over the past 4-5 fill ups, I've been getting horrible gas mileage on my '14 sedan - on the order of 25.6 mpg. I drive short, 4.5 mile trips to and from work 5 days a week. Been driving with ECON ON. Typical winter driving in the Pittsburgh area with outside temps in the 10-30˚ range. Running regular through it from a local station. Only 13.5k on the vehicle. What am I doing wrong? Should I be running with ECON OFF? Should I go with premium fuel? Seems like a waste for limited driving but this current low MPG return is bugging the living daylights out of me. I got these kinds of numbers on my '01 Accord up until I got into this '14 sedan. Stumped right now.
I don't think that mpg is bad under those conditions. Your motor never gets up to temperature. It take me 20 minutes of driving or 8 miles for my Civic to get fully warmed up even in the summer. You can try to change the air cleaner and fill up with top tier gas but don't expect a huge difference in mpg. You should also take at least a 30 minute highway drive once a week and do not be afraid to do some full throttle sprints to Decarbon the motor. Premium will help but don't expect my mpg.
 

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I don't think that mpg is bad under those conditions. Your motor never gets up to temperature. It take me 20 minutes of driving or 8 miles for my Civic to get fully warmed up even in the summer. You can try to change the air cleaner and fill up with top tier gas but don't expect a huge difference in mpg. You should also take at least a 30 minute highway drive once a week and do not be afraid to do some full throttle sprints to Decarbon the motor. Premium will help but don't expect my mpg.
Thanks for the input. I usually only end up filling up about once every 5-6 weeks or so for the limited amount of driving I do. I work for a retailer here in Pgh. who gives their employees "discount points" for filing up at the company-owned gas/quick-fuel/convenience chain of stores and have in the past always gone with 87. Pumps state that fuel may contain up to 10% Ethanol but I suspect that, with the onset of the western Pennsylvania winters last fall, may have bumped up the Ethanol content a bit.

Since I posted this series of replies in this thread I did some site searching and stumbled across the winter fuel thread and one of your replies about doing some sort of "reset" when you filled up. I left you another reply over in that thread about this possibility.

These winter MPG figures are what I got on my old '01 Accord sedan when I turned it in last fall against this '14 Civic. On a 16-year old vehicle!

Honestly, when I first got this '14 last fall, my mileage was around 32-35 and I wasn't really monitoring it earlier this winter until the last two fill-ups when I was shocked to see it had dropped to around 25.6. Even thought I had the fill-up/mileage figures done-up wrong the first time until I did a fill-up here on Monday and got 25.6 again.

I picked up this '14 sedan with only 12k on it in August and just rolled it over to 13.5k on Monday so you can see I hardly put any miles on it at all. The dealership did their complete CPO overhaul on it before I picked it up so I'm sure there's nothing wrong with the engine. Just never thought I'd get this poor a mileage so early on.

Thanks again for your input.
 

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i was going to say...go get it on the highway for 30-40 minutes....i think silver was onto something. carbon can be building up around the valves and such, since it never gets warmed up.

short drives are the worse thing you can do to a vehicle...and it sounds as if that is ALL you do. also, when was the last time you checked the air pressure in your tires. if you are looking to increase your mileage...i'd suggest adding anywhere from 4-7 psi above the recommended pressure stated on the label affixed to your door jamb. not what the tires say on the sidewalls.

check the spark plugs to see if anyone of them are fouled - a common issue with cold temps, short drives.
 

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i was going to say...go get it on the highway for 30-40 minutes....i think silver was onto something. carbon can be building up around the valves and such, since it never gets warmed up.

short drives are the worse thing you can do to a vehicle...and it sounds as if that is ALL you do. also, when was the last time you checked the air pressure in your tires. if you are looking to increase your mileage...i'd suggest adding anywhere from 4-7 psi above the recommended pressure stated on the label affixed to your door jamb. not what the tires say on the sidewalls.

check the spark plugs to see if anyone of them are fouled - a common issue with cold temps, short drives.
Thanks. S2C suggested I give it a "blow-out" too. PSI on tires is spot-on according to the specs. Will also check the plugs.

Thanks again.
 

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i know its not a civic, but with my 2015 honda fit cvt, i was getting better fuel mileage with the econ button off. seemed i would need more gas to get up to speed so maybe that affected it. i went from 4.9 L/100km in my fit to (so far my best) 7.4 L/100 km with the 15 si.
 

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Sorry if that sounded a bit smarmy on my part but I thought that, with 25k+ posts on your part, you might have already figured out that that's what I'd end up doing.
Wow, talk about jumping to conclusions . . .
 

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.i'd suggest adding anywhere from 4-7 psi above the recommended pressure stated on the label affixed to your door jamb. not what the tires say on the sidewalls.
Even with 2 psi over the recommended 32 psi, I have experienced excessive wear in the center of my tire treads. So if the tires wear out prematurely (more pressure on a narrow cross section of the tire means more weight, and faster wear), does that offset the slightly lower mpgs, or is it a wash?

Of course, tire wear doesn't hold the same importance for everyone.

I can only imagine what 7 psi over would do.
 

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Discussion Starter #92
i know its not a civic, but with my 2015 honda fit cvt, i was getting better fuel mileage with the econ button off. seemed i would need more gas to get up to speed so maybe that affected it. i went from 4.9 L/100km in my fit to (so far my best) 7.4 L/100 km with the 15 si.
I think its a CVT issue with the econ. My 12 Civic I would use the econ and get an average of 47 mpg most of the summer and broke 51 a few times.I just used premium gas with Honda oil and used econ with traction control on. When I started this thread it was with the 12 Civic. My 15 Civic I would turn off the traction control under windy conditions and I never really turned on the econ.

I have a ultra gauge and never seen a difference with econ on or off with the CVT but traction control I seen a leaner fuel trim with it on but better control of the throttle with it off with more timing. There is too many variables to pick on just one even a weak battery can effect mpg. Premium gas allows the engine to run MBT timing further in the rpm and load ranges. MBT timing will use the least amount of fuel at the most torque it can produce at that rpm. I use premium gas but its because of all the high speed highway driving I do.

Econ just slows the throttle response down and cycles the A/C and maybe slow the charge which lowers engine loads but I think learning how to use your foot is better to control mpg. I would also rev it higher at times and I do not try to get the best mpg all the time either about 25 % of the time I try to get better mpg.
 

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Discussion Starter #93
Even with 2 psi over the recommended 32 psi, I have experienced excessive wear in the center of my tire treads. So if the tires wear out prematurely (more pressure on a narrow cross section of the tire means more weight, and faster wear), does that offset the slightly lower mpgs, or is it a wash?

Of course, tire wear doesn't hold the same importance for everyone.

I can only imagine what 7 psi over would do.
In my Fit I would run 38 psi and it wore out the centers. The back tires need less air because they just skim the road. As the tires heat up the psi goes up too so in the winter you would want to add a few pounds more so you are not running low tire pressure when the deep cold hit but tire pressures need to be adjusted when going into spring and summer.
 

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I don't think that mpg is bad under those conditions. Your motor never gets up to temperature. It take me 20 minutes of driving or 8 miles for my Civic to get fully warmed up even in the summer. You can try to change the air cleaner and fill up with top tier gas but don't expect a huge difference in mpg. You should also take at least a 30 minute highway drive once a week and do not be afraid to do some full throttle sprints to Decarbon the motor. Premium will help but don't expect my mpg.
Just to update you on this. Last fill up I added a can of Techron to the tank. Just filled up again and mileage was up to 29.9 from last fill. Of course, the temps around here also went from 10-30˚ to 45-70˚ so that could have helped things along too. Will see if it holds up like this over the next couple of months.
 

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Gas stations may of also switched from winter gas to summer gas which does make a noticeable difference in MPG.

Just to update you on this. Last fill up I added a can of Techron to the tank. Just filled up again and mileage was up to 29.9 from last fill. Of course, the temps around here also went from 10-30˚ to 45-70˚ so that could have helped things along too. Will see if it holds up like this over the next couple of months.
 

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Yes, in order to get any meaningful data you have to limit changes to variables to one at a time. Then take readings and change another variable.
 

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Discussion Starter #97
I have been driving a all wheel drive HRV with the R18 motor. I filled up at a corporate owned BP station the last filled up. 7 gallons ultimate. It had 25 mpg driving home. Got to work this morning and the mpg was 35.5 mpg. This motor is so economical that I just might beat my best Civic mpg.

I thought my mpg would jump on the ride home but it remained the same. I was driving in a cross wind and had to turn off the traction control to maintain better control. I hardly have to press on the gas and still have plenty of power to pass. The main thing is to experiment with econ and traction control using the highest octane quality you can afford. It took me 3-1/2 tanks of premium to get a 8 mpg gain which pays the difference and it's not even that warm yet. Lights and heat are still being used too.

What I noticed is all Honda vehicles drive similar. There is a paper I have that explains the octane requirement for a 10.5 stock motor is 111 Ron fuel to be knock free and able to run at max torque. The difference between 91 and 98 Ron octane is about 30 plus percent in torque and fuel enrichnment. The new DI motors are different but still benefit.
 

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Gas stations may of also switched from winter gas to summer gas which does make a noticeable difference in MPG.
Stations around here (Pittsburgh, PA) don't start selling "cleaner gas" until around June (at least that's what the labels on the pumps say). Don't really know when the "changeover" from winter blend to summer blend occurs though.
 
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