Calling automatic Honda Fit owners

[Fit_is_slo]

First post here so here we go, I have a 2008 Honda Fit sport automatic I bought new years ago, I've been lurking here on and off for years and finally a few months ago decided to get serious about efficiency with it. I’ve done a few mods to it currently, I have lrr tires a decent hot air intake setup pulling off the fan shroud, a temporary upper grill block made of styrofoam and electrical tape, I’m soon going to do a lower block and block heater to it, but my biggest nag with my car is the tcc engagement, it will engage lightly at pretty slow speeds but even then any throttle kicks it off, 50mph seems to be the magic speed that it gives you more throttle before it disengages but even then it’s too conservative.
I want to do a lockup mod but I’ve acquired a wiring diagram for the transmission and don’t see a tcc wire on there, has anyone successfully done one on these cars? I’ve searched the forum pretty extensively and found the other threads but didn’t see any especially Honda specific information.
I’ve gone from a tank average of 27ish to 35 with mods and behavioral adjustments in mixed Atlanta suburbs driving.
Great community here I’ll try not to lurk in the shadows anymore

[mpg_numbers_guy]

Nice car! That's actually the exact other car I was looking at buying before I decided to go with my Civic. The reason that decided me was that Civics get better MPG once you reach speeds of 55 mph or higher (or so I've read from various sources). Fits decrease rapidly at highway speeds due to being taller, but excel in city driving due to the small engine and light weight construction.

Do you have pictures of your mods? Any plans on mods such as air dams or wheel covers?

[California98Civic]

The tank average improvement is great. Welcome to the site (again). At 35 mpg, you now are beating the Fuelly.com averages for a 2008 Fit Sport (32.2 right now). I don't know if an '04 Civic is necessarily better than the '08 Fit on fuel economy. On Fuelly the 04 Civic sedan gets 31.8 mpg. I think their CDA figures are siilar, Fit might be slightly better aerodynamically actually. I don't know the number. But the Fit has significantly shorter gearing at highway speeds: 5th is 0.757 and the FD is 4.294, whereas the 04 Civic base model had 0.711 and 4.111.

Originally Posted by Fit_is_slo

... I want to do a lockup mod but I’ve acquired a wiring diagram for the transmission and don’t see a tcc wire on there, has anyone successfully done one on these cars? I’ve searched the forum pretty extensively and found the other threads but didn’t see any especially Honda specific information. ...

I don't know the answer to this question, sorry. Maybe someone else does. Do you have the Fit's Factory Service Manual?

EDIT: More trnasmission specs for Fits on my honda manual transmission specs thread: http://ecomodder.com/forum/showthrea...ios-26279.html

But come to think of it, you have a automatic! Oooops! You might have nice tall gearing, not sure. Generally automatics are taller these days.

james

[mpg_numbers_guy]

Originally Posted by California98Civic

I don't know if an '04 Civic is necessarily better than the '08 Fit on fuel economy. On Fuelly the 04 Civic sedan gets 31.8 mpg. I think their CDA figures are siilar, Fit might be slightly better aerodynamically actually. I don't know the number. But the Fit has significantly shorter gearing at highway speeds: 5th is 0.757 and the FD is 4.294, whereas the 04 Civic base model had 0.711 and 4.111.

With the correct filters in place (1.7L, Sedan, EX) the Fuelly average for my '04 Civic is currently 33.26 mpg (see link). The '08 Fit I was looking at with the correct parameters (1.5L, Sport) gets 31.60 per Fuelly (link).

I honestly thought the Fit would get similar MPG on the highway and significantly better on the city, but most people on the internet say that the Fit beats the Civic only on slower speeds, but that (varying based on source) 55-60 is usually where the Fit starts sipping more. The Fit's taller gearing is responsible for this. I just looked up the coefficients of drag for both; the '08 Fit's is 0.35 and the '04 Civic's is 0.36.

Both are very fuel efficient vehicles and have Honda's legendary reliability and excellent fuel efficiency, so honestly both are good choices.

The longer highway trips I plan on taking won't account for slower speeds and excessive hypermiling, so I wanted something with better standard highway MPG, while I can hypermile in the city to get good city figures too.

Although if I could afford one, I would go with a 2015 or newer Fit, since they beat the comparable Civics by around 10%.

[Fit_is_slo]

Originally Posted by mpg_numbers_guy

Nice car! That's actually the exact other car I was looking at buying before I decided to go with my Civic. The reason that decided me was that Civics get better MPG once you reach speeds of 55 mph or higher (or so I've read from various sources). Fits decrease rapidly at highway speeds due to being taller, but excel in city driving due to the small engine and light weight construction.

Do you have pictures of your mods? Any plans on mods such as air dams or wheel covers?

It’s been a great car, in hindsight I would get it with a manual if I bought it over again but they were hard to find anyway when I got mine.
I don’t currently have any pictures I am contemplating a lower air dam than the factory one, not sure about wheel covers yet but I have a decent amount of coroplast coming so who knows haha

[Fit_is_slo]

Originally Posted by California98Civic

The tank average improvement is great. Welcome to the site (again). At 35 mpg, you now are beating the Fuelly.com averages for a 2008 Fit Sport (32.2 right now). I don't know if an '04 Civic is necessarily better than the '08 Fit on fuel economy. On Fuelly the 04 Civic sedan gets 31.8 mpg. I think their CDA figures are siilar, Fit might be slightly better aerodynamically actually. I don't know the number. But the Fit has significantly shorter gearing at highway speeds: 5th is 0.757 and the FD is 4.294, whereas the 04 Civic base model had 0.711 and 4.111.



I don't know the answer to this question, sorry. Maybe someone else does. Do you have the Fit's Factory Service Manual?



james

I don’t have one, I probably should after owning the car for a decade, I think I’ve decided not to bother with this idea for now and focus on drag/possible weight reduction, I acquired an engine block heater and some coroplast so when I have some free time I’ll get to work on next round of mods

[Ecky]

Weight reduction will have very little (or zero) impact on highway fuel economy. Just as an example, with my aero trailer, I get basically the same economy at 55mph pulling 1500lbs behind my 1900lb car as with an empty trailer. Stop and go is another matter, and it does improve acceleration if you can shed weight.

Definitely add coroplast.

[Daschicken]

You could go for a set of 1st gen insight rims, and either swap over your stock(?) 175/65/14s or go for the famous re92 165/65/14s.

[California98Civic]

Holy cow! You have really short gearing for an FE car on a Fit Sport auto from '08:

5-Speed Automatic Transmission Gear Ratios:
1st:2.996 - 2nd:1.679 - 3rd:1.067 - 4th:0.756 - 5th:0.550
Final Drive:4.560

Without a transmission swap, look for taller wheel/tire combinations to reduce RPMs at freeway speeds. Honda lists the factory tire size as 195/55-R15. I am confident you can get a 16" wheel that will be as light or lighter than stock and bolt onto your 4x100 hubs. But even with your existing wheels and stepping up to 195/65-R15 gives you a 4.2% reduction in freeway RPMs. Go to a 16" wheel and use 195/65 tires and you'll prolly get 9% or 10% reduction. Good luck.

[Fit_is_slo]

Originally Posted by California98Civic

Holy cow! You have really short gearing for an FE car on a Fit Sport auto from '08:

5-Speed Automatic Transmission Gear Ratios:
1st:2.996 - 2nd:1.679 - 3rd:1.067 - 4th:0.756 - 5th:0.550
Final Drive:4.560

Without a transmission swap, look for taller wheel/tire combinations to reduce RPMs at freeway speeds. Honda lists the factory tire size as 195/55-R15. I am confident you can get a 16" wheel that will be as light or lighter than stock and bolt onto your 4x100 hubs. But even with your existing wheels and stepping up to 195/65-R15 gives you a 4.2% reduction in freeway RPMs. Go to a 16" wheel and use 195/65 tires and you'll prolly get 9% or 10% reduction. Good luck.

I’m currently running a 205-50-15 on the car, Ventus V2 concept 2 (H457) Tire Info | Hankook Tire USA is what I’m using currently. Probably the wrong choices size wise for rolling resistance and aero on that car, I switched to that size years ago, this set is almost brand new though so it’ll be a while before I can switch