My first 2 tanks I got 40 mpg and 42 mpg but any highway driving around town I did was around 60mph. I took a road trip to the beach and drove around 75mph and only got 35 mpg. This was almost all highway driving so its got to be the speed. Wish I had a 6th gear

 

 

True, I am always between 32-37 (depending on headwind/tailwind) with my manual sport going 70-80
At a steady 65 or less I will get into the low 40's

Here is the deal that adds to the problem, the Fit is not particularly aerodynamic. Tall roof, stubby rear end.

This is my hope for the new model. Improved aerodynamics and a 6th gear.
I could easily live with an inch less headroom, and an 'aero, function over form styling' for example

 

I might have had some other weird factors (like tailwinds or something) but I averaged excellent (well over 40+) mpg doing about a steady 120km (72mph). I do have an CAI, but I am also wondering if my larger aftermarket tires had anything to do with that?

EDIT: Just an FYI on that, I tracked & verified my MPG using both a mapquest estimate between the stations and a scaled odometer reading because my speedo is out as a result of having larger diameter tires.

 

hehe on the highway i put on CC @ 80 mph...when its not on CC on tend to have it @ 90 mph+...then top end comes i just cant go under 80 mph i don not drive on the highway to go to work...just my road trips

 

Air resistance ( Drag ) increasess with square of speed !!!

 

in addition to that; the faster you go the higher the RPM you run & the more fuel you burn. 75mph with stock tires is what like 3500rpm?... that is getting close to Vtec engaugement point.

 

I definately get my best mileage at 70 Mph. I've gotten up to 47 Miles per gallon on I-81 going 70. However, anything over 75 really puts a drain on the MPGs.

 

80 is worse trust me haha

 

I did between 80-90 for a 4 hr trip, and I averaged 32mpg.

 

This is of course true. The problem is, reducing your speed may not be feasible. For me, I work 35 miles away and I gotta wake up at 610 to get there at 730. I can't really help but drive 80mph. If I worked closwer--which I did--I can take my time and drive 65.

 

Don't know what to say about that? I barely hit 3K at almost 80 mph. As far as I know Vtec engages at 3,400 rpms

 

Think that's the difference between an Automatic and a Manual, I think the auto has lower rpms in top gear at 70 compared to a manual in 5th at 70 mph.

 

Yes, top gear on an AT is quite a bit taller than the MT - at 70 mph the MT runs at about 3400 rpms. AFAIK from reading other threads, VTEC engages at different times depending on throttle pressure/load/etc. I seem to recall that it is always on at some point above 3k (3400?), but below that it depends on driving style and conditions.

 

If you do the math on this, it would only take you an extra 4 minutes to get there if you reduced your speed to 70.

 

LOL sad to say but 4 minutes is a lot of time. And time is money, no doubt about that. But through calculations I don't think it is too accurate in doing straight math like that, other factors can be involved and you can maybe save more time traveling at higher speeds.. I knew around 70mph would save me more gas but I like to travel at 79mph.. can't help it 70 seems a little slow on the interstate