Umm is anyone else going at 80mph at 4000rpm??!?!
#21
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.
#22
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.
#24
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.
#25
4,000rpm on the highway is normal for imports, but it's not normal for a car that has such a low redline. If I were at 4,000rpm AND had an 8,000rpm redline, I would consider it normal. We're at 2/3 of our total available rpm when cruising. As for the fuel mileage, there are many threads of people with the Scangauge that shows their economy drops drastically at higher speeds. Know way to know if that's due to the motor working so hard or wind resistance without doing a final drive swap and seeing the results.
If there's a final drive that is numerically lower that will fit, I'd be willing to try it.
If there's a final drive that is numerically lower that will fit, I'd be willing to try it.
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.
Last edited by pcs0snq; 03-20-2008 at 07:56 PM.
#26
4,000rpm on the highway is normal for imports, but it's not normal for a car that has such a low redline. If I were at 4,000rpm AND had an 8,000rpm redline, I would consider it normal. We're at 2/3 of our total available rpm when cruising. As for the fuel mileage, there are many threads of people with the Scangauge that shows their economy drops drastically at higher speeds. Know way to know if that's due to the motor working so hard or wind resistance without doing a final drive swap and seeing the results.
If there's a final drive that is numerically lower that will fit, I'd be willing to try it.
If there's a final drive that is numerically lower that will fit, I'd be willing to try it.
Last edited by SHG_Mike; 03-20-2008 at 10:32 PM.
#27
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.
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.
#29
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.
#30
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...
#31
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.
Originally Posted by GAFit
4,000rpm on the highway is normal for imports, but it's not normal for a car that has such a low redline. If I were at 4,000rpm AND had an 8,000rpm redline, I would consider it normal. We're at 2/3 of our total available rpm when cruising. As for the fuel mileage, there are many threads of people with the Scangauge that shows their economy drops drastically at higher speeds
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.
#32
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!
#33
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.
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.
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.
Last edited by GAFIT; 03-21-2008 at 03:37 PM.
#36
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.
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.
#38
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.