The gearing a manufacturer chooses is highly dependent on the amount of torque (at the flywheel) the engine produces. A low torque engine (small displacement) needs to be geared lower to have adequate acceleration for the target customer. A larger engine on the other hand has lots of torque already, and therefore doesn't need such a high gear ratio. The Fit's acceleration is already anemic at high freeway speeds, any lower gear ratio, would make acceleration unbearable. I think Honda comprimised and chose a ratio that gave acceptable fuel economy given the acceleration in 5th gear.

 

I agree. However, adding substantial torque (say through turbo/super charging) would allow a lower operating rpm. That's why I'd like to find a lower numerical final drive.

 

owned. great answer.

 

Far from it -- around here do anything less than 75 and you will get creamed by the semis, etc regardless that the limit is 65. That's reality, and I'm sure other locations have similar circumstances.

 

me too

I'm going to try a larger OD tire some day to prove the eco improves.

I think just like the TBW Honda screwed up. The Auto is way less RPM at speed with the same eng and the manual. Logic, based on eng curves, says they should be at the same RPM at speed yet they are way different. I have never seen any car with Auto Man option be so different like this.

 

Before the b16 i had the stock d16y7. with 110hp, you cant exactly fly up hills or what not in 5th gear. I drive on the highway to school 45 mins both ways with slight inclines and declines the average highway (not flat land like in FL but avg for NY). I got 3mpg MORE keeping it in 4th at 3200rpm cruising rather then 5th at 2300rpm. I can go into injector pulse width but, more gas is used under high load in low rpm rather then light load in higher rpm. Bascially in power band the less you need to lay into the throttle because of the efficiency of the motor at that rpm. Also the Fit was designed to be a small zippy car for the small streets of japan and europe not for large roads of speeds of 80mph. The car with any longer gearing would be a complete dog and would not accelerate for shit. No i GUESS in a perfect world with perfectly level roads and no lane changes or inclines or load changes... a longer gearing could be beneficial but again the longer the gearing, the more load you put on the engine to get up to speed unless you move extremely slow.

 

Due to the low displacement and low torque of the engine the manual is geared higher. The automatic can be geared lower due to the torque converter which allows it to slip and actually multiplies torque at low speeds.

 

at 80mph I think my S2000 is around 4k rpm in 6th

my old 2002 Civic EX was also right around 4000 at 80mph in 5th

sounds about right to me

 

I feel your pain and it might even be a tad higher than that. The only good part is that I can do 80-100 in 3-4 seconds without downshifting.

 

Speaking of wind resistance and the Fit - we've had some pretty strong winds in the north east these last few days, and I've noticed that it's been affecting the Fit much more than I remember it doing so with other vehicles I've driven. Perhaps because it's tall for it's size...

 

haha meant to type "it doesn't take"


I don't buy this. RPM alone does not play a direct role in fuel economy.

RPM + Throttle position, however, do.

If you are rolling at 80kM/h in 5th gear at 2500 RPM but are constantly having to use 20-30% throttle to keep that pace, then you are consuming more fuel than if you are at 80kM/h in 4th gear at 3700rpm using only 10% throttle.

 

You both need to take a trip to Montana then. No posted speed limits on certain roads during certain times.


Stock 4.10 gears?

You should see it with the 4.77's in the rear!

 

Agreed! Throttle position AND rpm determine fuel useage.

For every combustion stroke the fuel injector supplies fuel.
Throttle position and other factors determine the amount of fuel per stroke. The ecu controls the amount of fuel by altering the pulse width of the injector.

Total fuel useage over a given amount of time is determined by the rpm and pulse width of the injector.

Light throttle in top gear will keep the Fit happy on level ground at speeds as low as 50mph. That same light throttle will also propel the car to 80mph, but the fuel useage increases significantly because of the rpm.

 

mine runs at 3000rpm at 80mph, its a 08 auto, but i use the paddles to control it to that speed

 

no it doesn't and no you don't

 

As far as longevity goes, I doubt running higher rpms will have any effect.
None of my 4cyl bikes seemd to mind and one had over 200 000km's when I sold it.
You will burn more fuel, and if thats a problem you can always slow down.
My F250 has 4.30 gears and spins to fast for my liking at 120kmh.
So with fuel at $1.45 a litre this summer I had to slow down.

 

The auto is geared differently.

 

I actually think a longer gear ratio will lower gas mileage since youll be making less power at the lower rpms and youll have to use more throttle to maintain a speed. 4k is fine. Your not hurting your engine or lowering your mpg.

 

yea... thats normal dont worry about it.... you still get great mpg..... and it does not take that much money to fill it up

 

Regardless of the paddles, the AT does run 1,000 RPM lower at 80 than the manual Fit.