I too have nothing to gain from lying. I even topped off my tank a bit when I filled up after the trip (I know, it is a no-no) just to make sure I was really getting a full tank from which to compute my mileage. 29.5 mpg highway at an average of 90. Don't believe me? I don't believe it myself. Only one problem. It happened!

 

did it continue to happen after that trip? how fast do u drive now?

 

my driving is usually mixed, city based...usually get around 23mpg's.

This is my 2nd s2000....had similiar experiences with the 1st one, the 2000.

It doesn't mean i drive faster, unless the situation allows for it...driving from MKE to the Twin Cities, flat, wide open, perfect for setting the cruise at 80...would be stupid to apply the logic of FASTER MEANS BETTER MPG, SO LETS SPEED EVERYWHERE...

Using cruise alone will greatly improve your mpgs...

 

i have no clue, on the other hand you can garage your s2k for 120 years and barret jackson your car and make millions

 

120 is too long. 50 is about right. You want to catch the guys who lusted after your car when they were 14 just as they get rich enough to "finally get the car they always wanted as a kid".

 

As for the mileage, there are too many variables. For instance, I get in the mid-upper 20s on a long highway cruise, but I get about 8 on the racetrack. My average speed on the track is about the same as my average speed on the long cruise, but I attain that average in a completely different manner.

 

dyhppy and all:

As a matter of fact, the mileage trend has continued. Around 70+, 26.5 mpg. The faster I drive, the better it gets.

If I have to state a theory on why this is happening, it would be based on the fact that I have had fabricated and installed a major ram air scoop right behind the grill, sealed into the intake box. So it makes air resisitance air my friend, as well as my enemy. But that is just a theory.

But look, guys, I am a gold member of this board with over five years of s2k experience. And I've got much better things to do than to post lies on this board. Look at my posts. I have never been a "flamer" and have never been rude. I don't pretend to fully know why what is happening is happening. All I know is that it IS happening -- in spite of all the theories and engineering concepts to the contrary.

No, I don't think if I drove 130 that my mileage would still improve. I've never driven that speed that long to do a real test. It probably would not. But I'll never know.

What I report by example is ongoing. I won't pretend to be able to give a detailed explanation as to why. However, I don't think I'll take her to the shop and ask that this be fixed!

 

The car get better milage at higher speeds because at about 75 miles per hour curising on the highway in sixth gear the conditins are most favorable. Yet at lower speeds there is far less drag on the car and slightly less fuel being injected due to lower rpms, but the efficiency of the engine is not optimal. The efficiency is the greatest up in the high rpm range but gas milage is bad because so much fuel is being injected at full throttle.

 

It is totally conceivable that the S2000 gets better gas mileage at the higher velocity. I've seen my highest marks when traveling long trips at sustained velocities of 75-85 mph.

I can't say for sure without some telling data from Honda, but the engine is obviously more efficient at higher revs. An engine torque curves is a good indicator of it's volumetric efficiency curve. Peak torque is usually obtained at the engine speed corresponding to peak efficiency. This is the point when the engine is most efficient at burning the fuel-air mixture coming into the cylinders (the reason why the torque output is highest). Neglecting friction resistance inside the engine/drivetrain, at any given speed, an engine would provide the best fuel economy at peak torque. In the real world, however, this would rarely be the case (especially in the case of the F20 and it's astronomical peak torque engine speed).

Whether or not the engines higher efficiency can overcome the higher aerodynamics drag forces, mechanical friction forces, and any other number of a hundred factors, has yet to be proven definitively.

One interesting thought though...

We all can agree that we are going to get best fuel economy at very low throttle amounts corresponding to less air coming in, less fuel being used. I'd venture a guess that when most drivers travel at constant speeds on very long trips, they are not going 55 mph, but rather in the 70-80 mph range. The 55 mph range is much more common for a stop and go style of driving. I don't know anyone who travels 55 mph for a trip of 250-500 miles. Perhaps all of the high speed / high MPH data that we all have is biased because of that... Just a thought...

 

My above comment about engine efficiency and where it occurs is related to full throttle scenarios. Upon thinking about it, we really don't have the data we need to make claims about engine efficiencies I think. Engines have varying efficiencies not only at different engine speeds, but also throttle openings. A car traveling at 55 mph will require a different throttle percentage compared to one going 90 mph. Way too many factors here to get a definitive answer, but it is concievable that the engine is considerably more efficient at the higher speed.