Yup, I know when I drive the fit I can raise the mpg readout easily over what the other driver does in the car

I've found that to be true for the first few thousand miles, but once you dump that break in oil, and switch over to synthetic, I noticed an mpg drop of about 2mpg.
I've tried a few syn oils and all get passing marks from blackstone with 8k intervals but none make the engine as smooth/quiet/efficient as the break in oil was.
The car is 14 months old and has 30k miles on it, btw. I also noticed that over time, the MPG read out started reading low. First it would read 1-1.5mpg high, but starting at around 6,000 miles, it has been reading about 1-1.5mpg lower than actual, calculated mpg.

 

What grade was the syn that you put in? It may have been a tad thick. I would go further than 8K with syn. Oil intervals are much higher than many claim they are. You can probably get 10K from regular oil. Up to 15-18K with Syn. Of course no one really believes that, but I have seen it done with no harm. A high quality filter and these tighter engines, along with not letting the oil overheat and more additives used today makes for much longer lasting oil than we used to have.

 

unless you switch back to the original oil for an A-B-A test (or as close as you can get from honda) how can you be sure it's the oil? Especially when others have reported mpgs going up after switching.

 

What have others switched to? I have been told to go to 0w-20 after the break-in.

 

Honda (at least in my manual) says to leave the break in oil in until the first indicated oil change. It isn't a special oil but picks some things up used in the assembly of the engine that are good for it so it is best to leave it in. There is a forum my dad frequents called "bob is the oil guy". They are all about engine oils and have some good threads with analyzed oil and such.

 

I and I think others went with Mobil 1 0w-20 AFE as this Fit is for fuel economy. Although the AFE label is just marketing because of the 0w spec (see mobil1 FAQ where it says same formulation as unmarked 0w-20). So any 0w-20...pick your favorite brand.


Read any of the massive threads on first oil change for discussion and viewpoints on this subject.

 

Always 5w20, but I might switch to something a bit thicker to see if the roughness goes away. I would go longer but just change it when the oil minder gets to about 15%. Makes it easier to keep track.

Edit:
I'm assuming honda uses their 5w20 semi syn as break in, I might get a case of that and see how it works out.

If you can find me cases of the original break in oil, I'll buy it. Though I don't know whether it was intended to be used past initial break in.
If it's isn't the oil, what else is it? MPG readings with break in oil were within .6mpg of each other(of course there was a difference between summer and winter blend gasolines that was also accounted for) and readings after that with 2 different syn oils have been within 1mpg of each other, though always lower than initial numbers. The car is mainly used for commute to work so consistency is very easily achieved.
I can also vouch that this same thing happened when I had my 2008 Element.

 

You can give the honda-branded oil a try, which but it wouldn't be an exact test, because no one can really can get their hands on the precise oil from the actual factory-they don't sell it.
But as far as I remember from perusing BITOG both toyota/honda branded bottled oils have a higher dose of moly which do match closer to the oil analysis of the factory fill as compared to your typical store-bought oil.
But it's easily possible that just the wear and tear after, like the trans fluid wear might account for the difference... There's no way to tell unless you can grab someone else's semi-used factory fill to put back into your car.

 

[quote=TheOrangeRevolution;992028]Always 5w20, but I might switch to something a bit thicker to see if the roughness goes away. I would go longer but just change it when the oil minder gets to about 15%. Makes it easier to keep track.


Don't even go thicker. These engines are tight as a drum and "thicker" oil may not get into all the gaps. If anything go with the 0W and see what happens.

 

Break-in oils are generally a high detergent blend thinner than normal. Just gets everything cleaned out.

I wouldn't recommend running break in oil after the break in period... you could always just put in 0w20 conventional and throw in some ATF, probably about the same thing lol

inb4whoru

 

Thanks for that. I'm gonna try 0w20 before the honda oil comes in.

 

just as a note, IIRC, the honda/toyota oils in bottles come with either all of it or at least the additives made by Nippon/ENEOS, in Japan and supply maybe affected by the earthquake. So if you're looking to give it a try, you may want to try to get your hands on it sooner rather than later just in case of shortage. I think the typical sponsors for this forum carry it...
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Let us know how it turns out