Hi all,
Question on coil pack relationship to gas mileage. My 2010 Fit gets great highway gas mileage but only about 22 m.p.g. in the city. The car has about 119,000 miles and the coil packs have never been changed. Would anyone know if they are just about due to be changed anyway, if that would help with the gas mileage and if so, can someone recommend a brand name other than the original equipment? Or is it best to go with the original equipment from Honda? And is it advisable to change all four at this point of mileage?? Thank you for any information.

 

Personally, I would go with OE plugs. But yes, all four... there's little point into changing just one or two, unless they were very recently changed and had some sort of failure.

As for the mileage... I thought 100k was roughly where we would begin to consider changing the spark plug for maintenance... something related to their "no major maintenance for 100k miles" claims. But at the same time, there's no statement in the owner's manual about when to change it, other than when the code for (4) it popped in the maintenance minder. I didn't change mine until about 134k miles, though I forget if it popped before that and I just ignored it or something.

Now, about the MPG... I would think that unless there was something seriously wrong, even if it helped, it probably wouldn't be noticeable.

Incidentally, I get about 22-23 mpg around city... highway isn't much better. But then again, I know I'm fairly aggressive in my driving.

 

Coil packs are not usually a maintenance item but if they are cheap enough wouldn't hurt. Plugs are 100k miles if they are Iridium. I would replace all 4 and go OEM. Not sure how much it would help MPG. If it was actually causing MPG issues then I would think highway would take a hit too. City driving is not the best for the Fit it seems.

 

Thanks, Goobers. The plugs were changed one year ago so they are good. I still have my window sticker and according to that, the city mileage is supposed to be 27 m.p.g. but the "small letters" below that says that most drivers can go down to 22 m.p.g.! Well, I guess I'm "most drivers" because that's where I am. It's just that I've read from others on this board that they get much better city mileage than what I'm getting so I was wondering about the coil packs. But the car is running so frigging well, otherwise, maybe I shouldn't expect more city mileage and just go with the flow and not mess things up. After all, on the highway I've gotten as much as 43 m.p.g.! It's just hard to rationalize only getting 22 m.p.g. in the city with such a small car! Thanks again for your info.

 

Well, consider this... according to the bit on the top right of your post, you're in San Diego. Having lived there for a few years myself, I know its a pretty hilly/mountainous place. This is one of those places where highway driving will benefit way more, because it doesn't follow the dips/rises of those hill/mountains as tightly as a local road.

Can you imagine if the 805 didn't have to cross the 8, and followed the ground through that valley... just how many cars would even make it back up the other side without a massive "running start" and still maintain "highway" speed. It's was a freaking nightmare sometimes going from west bound 8 to north bound 805 in a 92 hp Mirage (aka Lancer)... that thing screamed like a banshee.

So yeah, I've read some of those claims too... but just like most things in life, not everything is equal. How would your MPG fair, if you were driving across the Bonneville Salt Flats? As opposed to just getting around area around SDSU? Hah, I'd say 22 mpg is pretty freaking good.

 

Thanks, Goobers. Well, even though where I live (close to downtown San Diego) the hills aren't that bad but I do find myself in extreme "stop and go" traffic---drive a few blocks, stop, then go again. But, when I had my old Saturn, I used to get in the high 20's when doing the same, city driving, on the same streets! That's why I was so surprised with 22 m.p.g. with such a small car. (And I'm an old gent and never jump on the peddle). But, if new coil packs won't give me 5 more m.p.g. there's no sense in changing them when the car is running so well. Thanks for your input and still sad about my mileage. :-(

 

You're sure everything else is up to snuff? Tire PSI? Its possible there have been other changes since the Saturn, aside from the car.

 

I had thought of tire pressure and will check it tomorrow by a hand gauge but I hadn't done that because the low tire pressure light on the dashboard has never lit up so I assumed the pressure was good. I will check that tomorrow and maybe "over inflate" just a little. :-) But all else seems to be good. No codes, etc. Thanks.

 

Factory recommended pressure is 33 psi... that's a compromise between comfort, mpg and handling... but a terrible compromise overall.

I pump my tires to about 38 psi when I was using 205/50/16 Continental EC DWS... though, since moving up to 17" wheels and 205/45/17 Conti EC DWS, I've decided to go with a slightly lower 36 psi... primarily due to the speedo. I'm pretty particular in this aspect, so I'd rather have it match.

That said, the TPMS light won't trigger until you're as low as 29 psi...

 

I lived in Hanover NH where it's basically all hills. Stop lights at bottom and top of each one -- basically the worst setup for fuel economy. In my crv my "city" economy would be a low as 15, much worse even than in Boston. If you are in a hilly area -- no surprise if you won't hit the EPA rating.

 

Checked the air pressure in the tires and on the side of each tire it calls for 44 p.s.i.! My tires checked in around 40 p.s.i. But I was under the idea that tire pressure was supposed to be what is stated on the label on the inside of the driver's door, which is 33 p.s.i.? At any rate, I think I'll leave the pressure where it is. Thanks guys.

And when it comes to comparing my old 1997 Saturn SL to this Honda, both are four cylinders but again, the Saturn got in the high 20's in the city (driving the same streets and neighborhood) and in the low 40's on the highway! And the Saturn was a bigger car. Oh well, if you can't do anything about something, forget it and glide along. :-)

 

Recommended tire pressure for the car is on the door sill, as you stated, which takes into account weight of the car, factory setup specs, etc. The pressure rating that is on the tire itself is a maximum cold pressure for those specific tires, really more of a do-not-exceed warning label.

 

Thanks for the info, Alfa38. Hey, with letting out some air, the lousy ride this car has, may improve! :-)