Hey folks! I used to have an '07 Fit Sport MT back in 2010, and got 42 MPG in that puppy without trying. Before I even knew about hypermiling.

Now, however, we've got a new-to-us Fit with 121,000 miles. It's the automatic with the select shift. I always use the select shift and I'm the main driver. My driving behavior is consists of hypermiling – slowly accelerating to target speed, shifting at lowest possible RPM, coasting in neutral to target minimum speed, rinse and repeat. This is a well-known technique called Engine-On Pulse & Glide.

That said, I still think I should be getting much better mileage than currently. I've only averaging 30, and the most recent fill-up was 350 miles of all 50-60 MPH roads, barely any traffic, barely any hill-climbing, etc. The fuel efficiency gauge on the dash projected 41 MPG, and from what I know of my previous Fit, it was very accurate. Unfortunately, I got almost 6 MPG less than that, and that seems to be the trend in this vehicle.

Therefore, I'm looking at mechanical reasons for this discrepancy. I've changed out the coolant, AT fluid and air filter, and replaced spark plugs. The transmission shifts like *butter* now. In a couple weeks, I'm changing the oil and filter, but they're not in bad shape now anyways. Tires on all tanks except this last one were at 29.5 PSI all-around. The sidewall says 51 PSI max, so I filled up to 45. I was really hoping that'd get me into the 40's, but saw no noticeable difference. Bummer.

I do think that the valve clearance needs adjusting, but the car isn't idling strangely or anything, so it's not a top priority. I'm not sure if this would cause a difference in fuel efficiency either.

I know that the 2nd gen Fit isn't as efficient as the 1st gen, but I do think I should at least hit the estimate. Also, I think I have a sway bar end link that needs replaced.

What are some mechanical things on a car of this mileage that I could tend to that might effect the efficiency?

 

I drive an MT 09 with just shy of 85k on the clock, routinely drive 75-80 Mph to work, 23 minute one way and I get 31 Mpg. Tires at 35-ish PSI, original plugs and coils, with added unsprung weight of a rear drum to disc conversion.

My gauge is innacurate. Honda had a TSB for reflashing the average Mpg reading, so I don't go by it, I do old fashioned math to figure it out. Now on to your car.

Gas is inconsistent over the course of a year and region. Some pumps offer %10 ethanol, some %15, some a blend, some run straight gas. Comparing MPG figures from 10 years ago to now isn't a fair comparison. To build on that I'm not sold on the idea of a "pulse and glide" technique for our cars. If there was some electrical assist to maintain speed I'd say go for it. Toyota and Honda employ something similar in their Prius and Insight. But where I'm not sold is the idea of shifting to neutral to save gas. If you just take your foot off the gas you shut down fuel flow, and the engine relies on kinetic energy to keep rotating. By shifting into neutral you have to burn gas to maintain an idle, and introduce a load on the transmission by switching back into drive to then speed back up. Furthermore you'd be introducing accelerated wear and tear on the driveline.

Flushing coolant is something recommended at 100k or ten years, but that wouldn't have improved mileage. The 2nd gen recommended tire PSI (maybe different for other years idk) is 33 Psi. It ain't an exacting science but my current Falkens like about 35 PSi to keep the sidewalls reasonably firm. If your valves were so far out of spec that an adjustment would improve mileage I reckon you'd already feel the side effects, so I don't put faith in a valve clearance adjustment fixing it.

Lastly, this is a 10 year old car. It isn't going to be as efficient or quick as it was new. I say take what it can give, and be happy you own a car that's as cheap as it is to run.

 

Definitely leaning toward it being just a 10 year old car and being happy with it. That said, I'm very much in the mindset of keeping it another ten years, and fuel efficiency is generally a good indicator of vehicle health.

I recommend you give a few tanks a shot with hypermiling techniques. You will notice a difference if they're normal trips you always take. I used to get 50% higher than EPA in our 2.0 liter Focus.

 

What kind of tires do you have? Do you do a lot of idling?

I averaged 30-33 with my 09 MT Fit and that was with summer tires and heavy wheels. If I did strickly highway driving with the factory sport wheels I would see over 35. I have seen as low as 28mpg with heavy AC use, idling alot and being in a hurry.

Also the cars MPG meter is off for most people. Mine registered about 3mpg higher then what I calculated. There may have been an update or something to fix the accuracy, can't remember.

There was also a thread around here of a member who cleaned a bunch of stuff and restored some lost MPG.

 

To be honest.
I would simplify your driving approach. Just as an experiment.
But I would stop driving with the manual shifters....just let the automatic transmission work as an automatic transmission. I kind of see the paddle shifters as just something to use on full moon nights for fun. But it's not a choice I make for daily driving. I know some do, that's just me.

And I would also bail on the hypermiling technique. Pulse and Glide doesn't have to be that complicated. IMO if you're driving in traffic and at any point while moving, shifting into neutral, it is simultaneously too much work, and also maybe most importantly potentially dangerous. Just stay in gear...and drive.

Just drive conservatively as far as your use of the gas pedal.- See what happens.

 

I agree, as well as I think being in any moving traffic situation and shifting in and out of neutral is dangerous.

 

It is always tough to nail down root causes of performance and fuel consumption drops on older cars. Do you have any check engine lights?

The 15% ethanol is just a tax you pay to farmers and GMO firms for votes; it reduces your gas mileage nearly 15%. That is a major driver for lower fuel economy (plus all the pollution from processing natural gas to fertilizer then transporting that fertilizer).

A few basic maintenance items I do on older cars; they always run much quieter and smoother afterwards. Maybe you can get a few more MPG but only way to know is to try. You can search the forums for more details:

Fuel
- Run only name brand gas. Try high test a few times as they have good detergents that clean the entire system. You can run a bottle of fuel system cleaner also. YMMV and some here disagree but these steps are cheap and easy.

Air
- Check for vacuum leaks, Sometimes you can hear a leak. Do a visual of hoses and gaskets. But with a DIY smoke machine or other you can find all the leaks. This is a most popular cause of poor performance. Easy to solve with smoke.

- You already changed the air filter (if not dry change it to a dry as the MAF can get fouled by oil)

- Clean the MAF (very delicate. only use MAF cleaner and let dry completely.

- Clean the throttlebody, butterfly and IAC (esp edges of butterfly). You don't need to remove TB but use only TB cleaner else you damage the coatings. Don't lose a finger. I have a buddy step on the gas to open the butterfly rather than force the butterfly open but I haven't done this on a Fit so research. (caution as don't want to spray off moly lubrication at butterfly valve)

- Clean EGR valve and passages. There are some good posts here. This step has boosted performance of several older GM cars my family owns.

- Replace PCV valve. $1.

- Adjust valves. Bernadi Honda told me they typically do this around 100k miles. Several people here complained exhaust valves get tight much earlier.

Spark
- Check posts here noting updated torque specs for spark plugs. A lot of us had some loosened spark plugs apparently undertorquing. Did you check gap was within spec on all plugs? (you can't touch the tip of the fancy plugs else uber thin coating of rare metals scrapes off.)

- Did your coils and boots all look like new?

- As you live in a wet area, you might want to check your electrical system. Have a shop test your battery and alternator (some chains do that for free). You can also do a voltage drop test around the system, clean major electrical contacts, redo voltage drop test.

If you have a cheap scan gauge that shows basic diagnostics, that can help, especially for issues that don't throw codes. For example, thermostat is running too cool. MAF is wonky. The ST & LT fuel trims are especially helpful for older cars IMHO.

Finally, if you don't have documentation on Honda services performed, you might want to see what other services you might perform. Might start with a brake check, brake fluid flush, accessory belt replace...

 

id say your doing ok with 30ish mpg. im totally carefree with my fuel...idle with the a/c on for 10-15 minutes sometimes..full throttle at will ...mixed with "taking it easy" , etc. with my stock intake i get 25ish mpg. with cone filter and exhaust i get 30ish mpg with this same behavior. (both primarily city miles) 60k miles on odo.

if you dont want to do a cone filter, AFE and K&N make a washable drop in filter that might boost your mpg. also driving with windows down creating drag could be a factor to consider especially if you are doing lots of highway miles. windows up vs windows down makes huge difference in my cars ability to accelerate past 70mph on freeway.

 

Thanks, Fiting! Great stuff here!

Just replaced the PCV yesterday.

When you say 'adjust valves', I'm assuming this is valve clearance?

And yes, I replaced the spark plugs soon after we got it. Three of four had blow-by and one was quite loose. I made sure to torque to the new specs (20 iirc), and I've checks the plugs since. Looking good.

I'll be sure to inspect the suspension more thoroughly when I get it jacked up this weekend.

 

So like me you’ve done most of the stuff you should in terms of maintenance and are still dissatisfied. I'm in the similar boat but your mpg is even worse -- I drove back from vacation last week, no rush at all so about 65 mph constant, and I got 41mpg. The highest mpg should be around the 45-55 mph speed range. So something is not right.

For me I suspect valves, and unfortunately that is one thing that is going to be hard to do myself (until we get a second car anyway). For you I might also suggest checking brakes-- a ever so slightly engaged parking brake could easily cause low mpg.

I suggest forgetting the paddle shifts and using the full auto. Imo the delay in responding when you pull the levers means you burn more gas with rev hang than you are saving trying to outsmart the car. Only use them to correct a gear that seems wrong, for example the car is in fourth but fifth will easily do -- the car of course has no idea if you are coming up on an uphill stretch or going to coast the next quarter mile to a stop.

 

Are you thinking you may need to replace valves? I'm considering doing valve adjustment soon. How does one know when valves need replaced?

I forwent the paddles today for a 70 mile roundtrip to my buddy's place to grab my jack and stands today. It was a fresh fill-up so the MPG calculator on the dash was reset. It got up to 41 just like on my trip where I did a bunch of tactics to keep it up. So I'm just going to sit back and enjoy driving the car instead of trying to max it out. It just drives me crazy that it won't get as good of mileage as our salvage title 2007 Ford Focus with a 2-liter did. But hey, I know it'll last a long time if I take care of it, and the emissions are way lower anyways. So I'm okay.

I'll continue to monitor it tank-to-tank using my spreadsheet, of course, to track any crazy changes.

 

Valve clearances need adjusting. Supposedly if they make noise that indicates they should be checked. Mine have always made noise, and are worse now than when new. They should never need replacing.

 

One thing that gets missed are the brakes. My coworker bought a used corolla that had a list of things that needed done that included a brake job. He replaced the calipers, pads and discs and would you believe that increased that MPG? We theorized that the calipers may have been sticking increasing drag on the discs and causing the lower MPG.

 

That’s funny. I had a salvage title 2005 Focus. That car was surprisingly awesome until I wrecked the crap out of it at Virginia International Raceway. The guy I sold it to wrecked it again within 3 months. I don’t remember mine getting better than about 33 mpg.

 

I've heard that. I've never really known what "valve noise" sounds like though.

Yep. It's got some brake noise up front. I need to figure out how to address it - never worked on brakes before.

I hypermiled the crap out of our Focus. It was manual, so I did the whole pule and glide, engine-off, then bump start with the clutch. It was pretty awesome. Totaled ours as well.

 

Valves dont get replaced unless theyre damaged by piston impact (snapped timing chain/belt) or if youve lapped them so many times that they can no longer meet the clearance specs when adjusted.

getting 40 mpg is beastly. I'm happy at 29. I think the motor is a little TOO small. if they put a 2.0 in her, and uh. reinforced the stupid flap that covers the spare .. or, now that you mention it, replace all carpet with higher quality pile. Velour! And maybe replace the seats with something more comfy in the bucket variety...
Hell shes got about 10 wasted inches of nose in the front bumper too..
The ac compressor wouldnt bog the motor down. add a real sixth gear
bring back the cable throttle!
Wheres my beer

 

That's funny pyts. I thought op was getting only 30mpg or less. At 40, it's unlikely to improve much more. I'm personally averaging around 32mpg (2/3city), and while that is worse than new, it's not a huge complaint ... My own complaint is around power and delivery being off. If I fix whatever is wrong - I expect mpg will go up a little - but losing 2-3 mpg over the course of 7 years is not abnormal. Keep in mind the EPA on these things is what ... 28/33?. Not as high as one might think.

 

Yeah, I know that. Hope the other poster knows.

I got 34 on my last tank - the best one of the five I have so far. The estimate on the dash said 41. Averaging 30 MPG over these five tanks.

Since I started driving normally, I'm enjoying the car much more. It's actually pretty spritely for being automatic.

 

If you can sand the rotors down, and be sure the pads can move just a little bit.

 

Lube the pins that hold the caliper on the bracing. If the caliper can't 'float' it won't center itself and drag on one side or another of the rotor.

I also 'exercise' the pistons by lightly pumping the brakes without the pads installed (one side of the caliper and then the other then move to the next caliper and repeat) so the piston comes out farther than normal but not too far as to blow it out of the caliper. I use a "C" clamp to get the piston all the way in and maybe a little more. Sometimes / some vehicles you can rotate the piston (boot stays stationary). All I'm trying to do is break up any caked up dirt / fluid rings that build up on the pistons and re-wet any seals in there. Sometimes it isn't enough and the pads are burning up and you have to replace the whole caliper.