Would anyone know what speed is best to cruise on a highway? As a Manual driver, when I hit 70, its around 3700 rpm and any higher speed than that, the rpm goes really high. So would anyone know whats the best speed to save the most gas?

 

I don't remember my sources (TV, fitfreakers, radio..), but from what I remembered the speed limit is supposedly the most optimal you should go for maximum gas efficiency on highway. The reasons were because if you go any faster than speed limit than you have a lot more wind resistance, therefore causing the engine to work harder. Another reason is the RPMs like you stated, if its too high its going to use more gas. On my automatic, when I am at 70mph its at 2500 rpm, but if I go up to 75 mph it will go to about 2900 rpm. I don't remember what the rpm for 65 mph and 55 mph are because I accelerate too quickly to 70 but i'm pretty sure it is around 2000rpm so it is the best speed to go at for max mpg. In SoCal, I find trying to go at max mpg speed is difficult because everyone is going 70+.

But so far with 70-75mph I have gotten 32 mpg (which is close to the EPA estimate for highway driving for 2008 AT,34mpg)

hope that helps!

 

I think this has been discussed elsewhere... maybe search a bit they have probably covered it pretty well...

having said that....ahemmm *clears throat*......

from what little I have noticed on my own and reading around 55-65.
in my '01 Civic coupe AT if I hit cruise @ 60mph...I would get sick mileage...much better I think than my '08 MT FS. But if I went anywher higher or lower it would suck gas up like it was going out of style ...but I also have done very little driving on the freeway so far in the Fit....sooo.....I....uhhhh....will hopefully be surprised or we will see...

In the Fit I would definately keep it under 70...and cruise seems to help a ton on this car and it works really well (I was very impressed)

 

i set cruise right under 70 to stay out of vtec (70=3500rpm in mtx), and i get around 30-32 (if i control myself on the backroads). if i went slower, it would probably improve, but if im going slower that 70 on the highway (when its clear conditions), im annoyed at going so slow. on the up-side, i dont really have to downshift for hills or anything. at 3500rpm theres enough power so you dont really have to drop speed unless theres traffic.

 

Once warmed up my Fit (auto) gets the following mileage at steady cruise. (46 psi in tires, Mobil 1, 70 degrees outside temp)

35 mph=55 mpg, 40 mph=47 mpg, 60 mph= 42 mpg, 65 mph= 41 mpg, and 70 mph= 38 mpg.

These numbers come from the scanguage, with the ac off. ( The auto fit turns 2250 rpm at 60 mph)

 

something is strange here:
when i cruise at 80 my rpm is like 2900 just below 3k..?
i have the auto...it seems odd that its revving so much higher for you guys - do u have manuals?

 

I cruise between 60mph and 70mph, usually 65mph, but it just depends on the flow of traffic. If it's late at night and almost no one is around, I'll go a leisurely 55mph so I can listen to the rest of whatever CD I'm playing. I hate how high the MTs revs go on the highway.

 

dang im glad we got the auto sport...with alot of trips to fl im gonna like the low rpm's and better gas mileage.

 

3700 on the at 70!?!? Thats crazy high, mines under or just 3 at 70mph.
Anyway roll 65mph for good MPG!

Tyler

 

Yea I don't know why the MT fit's have higher rev points at higher speeds. Maybe its because auto is a 4 speed transmission? But I don't know what I'm talking about here. MT should be lower in RPM at 5th, but thats just the way the gear ratios were set. It sucks seeing it that high when I like going 70 or so.

 

By a large margin, manuals Fits get much better mileage than autos in all situations.

 

If I remember correctly Honda test their vehicles at 55mph to come up with the mpg. So probably somewhere in that range will give you the best mpg.

 

It's the US Government who tests the vehicles on their road course to come up with the numbers on the window sticker. Prior to 2008 you will notice higher fuel economy ratings then you will on the same cars after 2008. This is due to changes in how the tests are performed.

New tests are designed to imitate real world conditions more accurately (faster highway speeds, AC turned on, etc)

As for my car: when conditions are right (moderate temps, low dewpoint) it seems to have a sweet spot between 60-65. I would like to try 55 once, but there are no highways here where it is safe to go that slow.

 

the auto is also a 5 speed, its just geared lower

 

not the way i drive them.

 

I thought It meant it was geared higher?
All I have to do is look it up...how lazy am I?

 

I gotta get me that scanguage..... It looks/seems sooooo nifty....
I could only imagine how much fun it would be with my MT....hmmmm

 

yeah id like to see a pic of that set up in a fit

 

There is a "huge" thread with it...I will throw you in the right direction when I find it again...(I lost it even though I subscribed to it )

It doesnt look as bad as I thought it would....
I would love it if they made a circular one....

 

I've averaged 40.1 since new (9000 miles) with an auto. The auto revs less. I don't know Why Honda did that.