Forgive my lousy google-fu, if this has been asked before. I've had my Fit ['07 sport, manual, 63,500 miles give or take] since May, and so far am really loving it...my toy sits unused, simply because my daily driver is a fun drive in and of itself...plus money's tight right now, unable to afford the 30c/gallon and 15mpg premium for driving a high-power, turbocharged car.

Since late October, early November, my efficiency has been steadily marching downhill. Where I was getting 35-58mpg out of it, now I'm getting 29-32. I haven't changed my driving habits at all, and the only hardware change was replacing my bald tires with an OEM set, but that was in January...long after this started.

It's also felt down on power, sluggish, so on and so forth, needing more encouragement than it used to to go up the hills near my apartment. Dad said he felt a slight miss when I asked him to check it out, and said plugs were a no-brainer.

After scratching my head under the hood for a few minutes, trying to find and trace ignition wires before coming here and finding out it's got a coil-on-plug setup, I called my local dealer about it. They told me that the plugs should be good until the 100,000 mark, that if I was willing to bring it in they'd spend an hour or two running diagnostics.

My other car's a Stealth(3000GT); I'm used to a situation where every little thing has a gotcha or three attached, so it's time to ask other owners. Are there any 'gotchas' for a GD of mine's age/mileage, things that commonly fail right about now? Do these cars just really, really hate winter blend gas?

I've been religious about checking my tire pressure; since getting the new tires they haven't needed inflated at all. Two tanks ago I gave it a bottle of fuel system cleaner and a new air filter, but that seems to have made the problem worse, not better.

The ECU isn't throwing any codes at current; no CEL, no MM. The oil's reading 40%. It just came off safety inspection; since they didn't find anything relating to sticking/dragging/etc brakes, I don't think that's a factor.

I've talked to the previous (and also first) owner; he said it did drop off for him in the winter too, but not to the degree I'm experiencing. From the records I have, he took good care of it...dealer serviced as soon as the MM threw a code. Speaking of, the Maintenance Minder threw the 50,000 service code at 58,000-59,000, and closing in on 65,000 has yet to throw the 60,000 code.

The only other thing that might be relevant is that I was running very late for Thanksgiving Dinner, and did have it spun pretty far up...half an hour on the highway at 75-80mph...but the slide started between 2 weeks and a month before that, so it can't be the root cause but could be a contributing factor.

Is it time to pull the plugs and check the gaps, or is there possibly something else at play?

Thanks ahead of time!

 

sounds like you need to readjust the valves and a tune up.

 

Run the valves? Wow...I was under the impression that was a thing of the past. I'll have to call Dad about it; he'll know what I'm in for, and probably have a few more stories about his Nova/my uncle's Challenger while he's at it that he'll get nostalgic about that. Granted, chances are he's about 30 years out of practice on doing it...he hasn't done that since the 80s, gave me the impression that was a thing of the past.

You wouldn't happen to know what the book time on checking/adjusting them is, would you? I'm not about to run the valves in a snowy parking lot (the joys of being a renter), so this time it'll have to be done professionally. Hopefully I'm not getting in over my head, or risking extreme damage if I have to save up a couple months for it...money's tight with me trying to move into a cheaper apartment.

In the meantime the next time the weather cooperates, I'll check/regap the plugs to hopefully stave off some of the efficiency loss.

 

what are you meaning by "RUNNING" the valves?

he said "readjusting" the valves. we do it on all cars around 100k.

 

Probably a local dialect thing. Running the valves: Pop the cover off, bring 'em back into tolerance.

If you're saying that all cars get it eventually, then that's a lack of knowledge on my part. My relatives/mechanically-inclined friends talk about it needing done on classic hardware like it's no less routine than changing the air filter, but they all talk about running the valves as 'in days gone by', as if manufacturers found a way to make them self-adjusting.

Hence my surprise.

 

29-32 MPG sounds right to me. That's actually what Honda says the Fit will get and they get those numbers driving in perfect conditions on flat ground with minimal weight in the car. In the city, I get around 23 MPG, but can get well over 30 driving all freeway. Plus the car feeling under powered is probably just the car. It's a 1.5L. It's gutless.

I would still check the valve clearance, change the filter, check your tire pressure, are you carrying un needed weight in the car? There are lot's of factors to remember when trying to get your best mpg.

 

cold weather = denser air = your car gives your engine more fuel to compensate.

 

I was surprised when I test drove it back in May...Honda advertises them as peppy little things, and I'd known they were geared really short, but I wasn't expecting it to be that...enthusiastic. It wanted to rip through the gears, and to keep the revs down I was happy to oblige.

I'm trying to compare to when I bought it, back in May...downshifting to not bog down/stall out on hills that I could just cruise up before, things like that. Sure, it's not going to pick a fight with my modded Stealth any time soon, but it's also not the V6 '84 Marquis I had, either. Calling that thing one-lung would've been an insult to gutless cars; it did 0-60 if it felt like it, and 0-75 in "Uhhh, no. Go away". Anyway, I can bag on the car that tried to kill me later...back to the Fit. As recently as early October, I was getting 34-36mpg running around town, and 39-41 running overland...a full 20% drop to where it is now.

Tire pressure's good, air filter and tires are less than a month old [OEM size], nothing in the back but my emergency tire pump and jumper cables. I stand corrected on the oil...it's down to 20%, not 40%.

Here's to hoping the weather cooperates soon, I'll at least check the plug gaps once it does...and schedule it to have the valves run as soon as I can afford it. At $130 a pop for genuine imitations, I hope the coils starting to wear out isn't part of the equation. I can't afford a $600 ignition job right now, though thankfully they're as easy to change as the air filter on these cars, so I wouldn't be spending anything on labor. I wouldn't think so, it doesn't even have 65,000 on the clock yet.

Anyway...thanks again for the continued help, guys. I imagine I'm going to learn a lot by owning this car.

 

I'd readjust the valves, maybe change the plugs, just a basic tune up, but mostly I'd place the blame on the cold weather/denser air. I mean I went from 40 mpg in the summer/fall to 32-34 in the winter.

 

Colder weather raises the viscosity of the engine and transmission fluids and the A/F ratio is much richer at start up... You are probably using your lights and heater/ defroster more also... The new tires will weigh more than the worn ones you replaced, new rubber isn't as resilient in cold weather as worn tires are and the new tread increases rolling resistance... Unless you are driving at highway speeds for many miles after starting the engine in cold weather there is going to be a sizable loss of fuel mileage mostly because of the reasons above.

 

how often are you running the defroster? when the defrost is on, you're using the AC compressor which eats mileage. only use the defroster when needed then switch it off to something else..

edit; don't believe all the "recommendations" the honda manual says. i changed my plugs at 85k and noticed a difference along with adjust valves at 90k which needed to be done FOR SURE.

 

Wow, Ive had my 07 fit sport AT for a couple months and it has 67xxx miles on it, and i drive about 50 miles a day, mixed highway and town, ive gotten at best 27 mpg's, my last tank was 21 mpg's, how are you guys getting high 30's low 40's mpg out of these cars? I have 18" rims and tires, and an axle back but thats it! New filter, fresh oil, cruise always used on highway! i have all the service records, Im the third owner.....So, Foxden, I feel your pain!!!

 

It's because of your heavy 18's and your autotragic transmission.

 

Our fuel composition changes relatively dramatically in the winter as well.

 

Actually, the "heavy" 18"s didnt change it that much from the stock 15"s, And I cant see the manual getting over 10 mpg's better than my "autotragic" The fit is my daily driver, If i want fast, Ill get my 95 300zx out! Hell it gets as good of gas milage as this fit! haha

 

I'll give you an example.

I average about 37-40 mpg, with my 5MT base.

The original Mike410, with his 5AT Sport, lightweight wheels/tyres averages about 28-32.

 

Not too terribly often; it's been a very mild winter up here, normally I can get away with just the heater blasting the footwell...I'd say I've run the defroster maybe 10-15 times, all the way back to that random storm we got around Halloween. I did notice about the A/C comes on for defrost...impact's about the same as a 200lb passenger, which certainly doesn't help but can't be the whole answer.

At this point not much I can do but pray for a warm weekend and to find the gap specs somewhere. I can't do the valves myself in this weather, and wouldn't want to without someone experienced standing over my shoulder...just in case. Changing a belt or an accessory is one thing; potentially destroying the internals, preventing it from getting proper compression, or outright ruining the timing is another.

Editing for some of the other posts.
21mpg? Ouch. Make sure the swap from stockers to 18s didn't screw with your odo readings. If the circumference doesn't come out to the same, you'll be going a lot further than the car realizes, which means the number you're using for your calculations is off on the low side.

To the DSMer, I do wonder how much of the impact is winter blend...it did start to plummet right about the time the blends change over. I wouldn't think it would be a full 20% drop, though. The previous owner linked me to his Fuelly account; he saw a drop to the same spot [28-30] in the winters...but then again he was lucky to hit 34 in the summer, which for me is a sign I was running it too hard or did a lot of people-moving.

I feel you on hard driving, Ken.. If I want the thrill of hard acceleration I bust out my Stealth...I bought a daily driver so that I wasn't getting 21-24mpg on $4/gal hi-test gas (not to mention wear and tear costs on a 3/S are painful), and bought a Fit specifically because it nicely proves you don't need big power to have big fun behind the wheel. This car's a lot of fun for tearing up the twisties [a reviewer stating 'pick a pebble on the apex, then hit it effortlessly' wasn't kidding], but it isn't going to give me a headache by smashing my skull of the headrest like the Stealth will.

 

Larger wheels and tires on a car is like walking while wearing a pair of jungle boots covered with sticky red clay... My fuel mileage dropped from 33.5 MPG to as low as 26 by changing from 195-55-15" tires on 9.5lb wheels to 205-50-16" tires on 12.8 lb wheels.... The larger heavier wheels and tires have also taken a toll on acceleration both from a dead stop and when passing on the highway and that is with a supercharged engine taking 10PSI boost and a few other performance enhancements.... Next to boost the best performance for the money you can get is lighter wheels and tires... Smaller diameter lighter tires would make a positive improvement on an automatic equipped car.

 

my autotragic rolls about 35-37 MPG on premium. of course i'm also rolling 70-80 on the interstate (mostly 75) and florida is all flat. except those on-ramps, which they consider hills

and i've got lightweight wheels/tires


and bigken, dump the cruise if you're near hills b/c it'll just pull trying to keep up (but you probably already know that)

if you've done everything you can think of you might even want to do the whole unhooking of the battery, waiting 10 minutes, re-hooking leg work to get the ECU adjusted (is that even the right lingo?)

maybe it just needs a lil' love?

 

My belief is that the gasoline is causing the most of the mileage drops. Ever since this ethanol crap started being put in gas tanks, my cars have gotten crummy mileage, and my '95 Camry has its check engine light on most of the time, although there is not a thing wrong with it. It just hates the corn products in its engine.

I think the winter blend gas is worse than summer, but in summer around here, it's humid and hot so I get really laggy performance and bad mileage too. If I didn't love this car as much as I do...