It's an interesting story line developing here. I'm really surprised everyone is everyone is all oversee map with these fuel mileages being posted. Also surprised that it appears posters didn't pursue their thoughts with Honda.

I will be pursuing this with Honda, regardless of how much it improves. I would like to hear their thoughts on break in. Dealer never mentioned it. Honda doesnt address it on their website. I'll google Honda new car break in and see what pops up. Maybe edmunds will have something about it.

And yet other posters, are getting high 30's from the getgo! Very interesting. And good discussion. I'll reset the ECU today.

Steve

 

Some very interesting reading on how to operate your car to maximize fuel economy.

Low rpm, high torque is the zone you want to be. Would love to be able to get ahold of the torque load tables for the Fit. Would put a lot of debate to rest.

Check it out:

Fuel economy-maximizing behaviors - Wikipedia, the free encyclopedia

 

I'm headed for California today, I will let you know how it does highway. I hand calculate 37mpg city so far.

FWIW, I went a half tank driving more aggressively, Heavy acceleration, many full throttle runs to freeway speeds and got 34.7 mpg.

Normally I drive very conservative, accelerate smoothly and consistently, I short shift using 5th gear when cruising at 40mph.

 

Peak torque is at about 4800 rpm. You can find the chart at The Truly Amazing Honda Fit/Jazz towards the bottom. 2000 rpm is way to early to shift this car.

 

I really don't drive very far on a daily basis.I did drive my car very aggressive yesterday for a short distance and returned 25.3 on the computer

This was done with a few full throttle blast in both D and sport mode
I have a little over 5K on my 2012 Sport A/T

The thing is if I drive for max mpg around L.A. I will be run over and cursed at
I can average 28 pretty easy so I'm happy.

hope things get worked out for ya Steve because I can see your point with Honda

 

Update! I hand calculated 42.33 mpg highway driving at roughly 73mph. I'm pretty happy with that!

 

Update:

Last tankful.........





Wait for it........



Not yet.....


Boohray!!.......30.16mpg.

Break in THAT significant? I'm really shocked. Humbled and shocked, actually. I gave Honda the benefit of the doubt. Even with taking it back to the dealer on the off chance it wouldn't improve. At least the file was opened.

Reading online, Honda makes more engines than any other mfr in the world. So you gotta think they know what they are doing.

This thread might be a consideration for sticky? I was surprised to see others hadn't questioned their initial low mileage. I know some are getting good mileage right out of the shoot; but probably more times than not experience what I have.

I'll hope to see a few more upticks. But at 30mpg all around driving, I'd be fairly happy with that. Would like to see 32-33mpg all around driving. Then I would say, ok....that's really dead center of the zone.

I'll keep posting for a few more tankfuls on this for trending. Very interesting! Still have yet to talk with Honda concerning this break in stuff.

Thanks!

Steve

 

WOW! That's great! Yea, probably a squirrely break in.

However, even after averaging 31 my avg dropped to 28mpg in the city this tank but I quickly got it back up to 30mpg avg with some freeway driving.

Sounds like you don't have a lemon after all.

 

The problem is counter-intuitive for many and contradicting what it says in the manual, I find it pays dividends in the long run to beat the utter sh*t out of them for the first couple oil changes (using high moly/zddp dino juice)

Seal those rings, break in the bores and cam lobes as FAST as you can. The first startup, specifically the first half-hour of run time is the most critical.

Don't baby it, or you may never get a proper break in. Power is down, effective compression is lower and fuel consumption as a byproduct will be greater.

It's been my mantra for years and it has yet to fail me. Many other reputable builders swear by it as well as a few Major OE's (BMW M-division for instance)

The Honda owners manual may say otherwise, and many will point to that as unassailable truth, but in reality its not.

My best tank was 44.x mpg on a 450 mile trip back from the cabin, granted I had a couple gallons of C16 in the tank as well just for fun, but the car was also loaded down with people and equipment going 70mph the whole way.

The car now has (as of this morning actually) 41k on her and has already had one turbocharger kit installed and removed.. never has it needed more than fluid and filter change as far as the engine is concerned.

Long rant short, as she breaks in it'll get better. Then it will come down to your operation habits, environment and commute.

 

I myself would still consider 30mpg unacceptable, but you may live in a different environment than I do, I live in a pretty populated area but its not constant stop & go city driving. I don't waste any time pulling away from red lights though & I still average at least 33 mpg. Hopefully your mpg keeps improving, but I wouldn't rest with Honda if it doesn't. Have you found the mpg gauge to be pretty accurate? After the update for mine I've found that its pretty close.

 

30mpg is the epa average though.

 

Ring seal's the key. Spent the first 20 minutes focusing on this, on the sidestreet in next to the dealer. First tankful averaged 37mpg.

 

Did you accomplish this by just revving the engine in neutral? If so what RPM did you go up to and for how long?

 

First gear, rev to 6000, decelerate. Do this 3 times in 1st, the same in 2nd and 3rd if theres room. Let the car cool. Do it again. Ring seal takes place under extreme combustion pressure, which takes place during decel. Highest mpg so far is 41.5.

 

Well you want to vary the throttle and keep it above 2k while you let the motor warm up.. then go and do your decel runs.

BTW there is no combustion going on during engine braking when TPS is 0, and you are letting compression slow you down.

The motor is pulling vacuum (MAP sensor voltage and a physical gauge would show you this) when the throttle shuts and when the RPM is >1000 for the MT Fits no fuel is being delivered after the over-run, so Im not sure where you got it into your head that "extreme combustion pressure" is taking place under engine breaking

This is a fact on all EFI cars btw and both the AEM and Scangauge confirm this before you retort.

 

That is very excessive. You basically need highway driving for longer than 10 miles varying speeds with a few full throttle passes. You are basically building a map that covers all conditions. Engine loads are very high when taking off from a stop and that load is good enough to seat the rings, the problem is breaking the engine with short trips. My wife's car is a perfect example of this. She drove the car very hard but the short trips hurt the mpg and I believe the engine did not break in right. The car never drove right and I had to get rid of it. 22-26 mpg was the best I could do when my car is getting low 40s in mixed driving. We had the same type of car a 2010 Civic.

 

Been doing it this way for many many years. Street cars, race cars, bikes. Look it up.

 

Just said it was excessive, I did not say it would not work. I see higher mpg when I drive aggressive on the highway but I also use premium gas.

Wife's car I blame on short trips on regular gas.

 

Congratulations. 30 mpg is a large improvement!

Along with break in, did you adjust your driving style on this tank?

 

On the 30mpg fill up tank, I left it in automatic. Let the computer do the shifting with normal accelerations.

This tank, I have decided to do the heat thing. Makes sense and can't really hurt. Car has 900 miles on it now; so on the one hand, it might be too late to have the rings seat themselves solid with high rpm. On the otherhand, in my mind at least, it allowed for the engine to get situated before running it up to redline. I'll do that for a day or two and let it go at that. Then back to normal driving.

Heat makes sense. But going away from the mfr recommendations (which I don't know what they are frankly), seems odd. Honda would put out some guidance if heat resulted in less oil leak in the future, and a more efficient compression for the life of the car, hence better gas mileage. Makes sense....but why doesn't Honda recommend this?

Also is the issue of the first oil change. I have always changed the oil at 1000 miles on my car. Dealership says no. Don't do it until the light comes on. Don't know what it's set at....probably 3k?

There are no additives in the oil from the factory on a new car. To me it makes sense to change the oil at 1k, to get rid of the metal shavings. And letting the car run for the duration of the first oil change in my mind only means there are shavings in their for the duration, unnecessarily creating internal engine wear.

But that was on engines of old. Maybe new ones are somehow different. Again, the mfr says let it run until the light comes on. So I'm going to stick with that.

I seat the piston rings though. Best I can with 900 miles on the car. I would think you would want to do that right away, as one poster did at the dealership....getting I think 41mpg from the getgo.

More guidance from Honda sure would help. Have yet to contact them directly on this break in philosophy. My guess is they will say to just run the car normal. Don't baby it and don't beat it.

Who's to know!