Better mileage going 65 than 60?
 

This is in a '93 Civic 2dr DX 5spd, all stock...

I've noticed the past few tanks that I'm getting better mileage going 65-70 than I do going 60mph. I've been speeding lately because I seem to always be running late to school or work.

Additionally, as I look over my gas log, most of my tanks where my mileage is on the higher end of the spectrum, I note that I wasn't driving efficiently, I was speeding everywhere and/or generally driving like a maniac, sitting in traffic, go through drive-throughs. Yet when I baby the car, drive no faster than 60mph, don't sit through any drive-throughs, my mileage doesn't seem to increase.

I guess this is exactly why a SuperMID is vital to have. I will definitely have to try to get one at some point.

Has anybody else noticed anything quirky like this? Until my mileage shows otherwise, I'm going to start speeding!

You just have to love the way that people tend to take a 'one size fits all' approach to improving fuel economy. But the truth is that this almost never works. Every car is a little different. Drag coefficint is NOT a constant, and can actually DECREASE with increasing speed over some range(s) of speed. And it is also quite possible that your engine (like SO many Honda engines) is just not very happy cruising at low RPMs. So you just have to experiment to see what gives you the best mileage. Because you can't take it for granted that it will ALWAYS be in the 55-60MPH range.

Enjoy it. Drive faster than other GasSavers.org members.

How many RPM is 70mph for you?

Can any other ~1993 DX drivers chime in with their own results?

In for this. My last tank was my best tank yet pulse and gliding 50-60mph. On this tank I had the opportunity to P&G 45-60 on the first quarter tank and it seems to have gotten worse. Slower is not always better.

I wish I can have some sort of fuel instrumentation too but it's not happening on my car any time soon.

Sort of the same car. Mine is a 96, so it's got the 1.6L engine instead of 1.5.

Some examples, on the same 150 mile route:
P&G 60-70: 55 mpg
P&G 50-65: 63 mpg
P&G 45-60: 67 mpg

This is with heavy use of pulse-and-glide. In some cases, on hills for example, a lower limit of 45 is too low for p&g, and 50 will be better. However, the upper limit can't get too high or mileage will start dropping off. Above 60 is too high for the best mileage.

There are options, but none of them are as easy or as nice as the ScanGauge. Check out the DIY fuel rate meter link in my sig.

One more thing:

For a test, one time, I did a straight, nearly flat segment at 15-30 mph p&g, driving like I was in a competition. 85 mpg.

^^ Yup I got that. It was helpful but still very limited. I have Honda's DPFI system it uses 2 different sized injectors and it's confusing as hell and seems completely random.
I was able to confirm that at steady throttle I get the same FE at 50mph and 55mph. 60mph and it starts to go downhill.

Check out the MPGuino project at ecomodder. It might work for you.

I drove a '94 Civic DX Coupe to 52.5mpg over a 500+miles tank. I was babying it. I did go 70mph briefly on the highway, but i think I was mostly doing 65 on the highway. I didn't know about P&G at the time, although I did some toward the end of the tank. I've had a few instances where my mileage didn't increase when I babied it more.... There does seem to be an ideal acceleration rate and cruise rate for each vehicle. But what you are describing doesn't really make sense. Describe what you mean by driving like a maniac. And describe what babying it means for you. If you are accelerating too slowly and never getting up to speed then that isn't good either. What RPMs do you shift at when babying it? What RPM do you shift at when driving like a maniac? Idling really doesn't use that much gas.. so it's more how you are accelerating and how much you are breaking that has more impact on mileage than whether you idled through a few drive thrus during the course of the tank.

Pulse and gliding, who wants to drive like that, for how many mpg more...

Sometimes, in some places, in some occasions, its a great technique (not EOC...), but does someone do it in the highway during a 1 hour travel? I wouldnt be able do always play with the stick, too much annoying.

I P&EOC for the non-highway portions of my commute, which are 60% of the mileage (and probably 80% of the time). I don't have the patience to P&G on the highway...the speeds are too high to coast well and I don't have as much speed margin to work with.

I do EOC for highway descents steep enough that the car won't slow down much.

it's not a honda but my S10 gets better mpgs the faster I go and the harder I beat on it. best mpgs ever were with a friend and 300 lbs of stuff in back doing 70-80 mph very aggressively in freeway traffic

One thing that should be noted is the human tendency to want to see
a benefit inside of something we're doing that isn't quite right, so as to
give ourselves a reason why we should continue said behavior.

As a rule faster usually isn't better, but more and more cars made
after the 80's were tuned to run at today's highway speeds of 60-65 mph.

It has a lot to do with a car engine's particular power curve,
aerodynamic drag is but a small part of what the engine has to do
so where the engine hums its best is usually the best mpg also.

Yet another reason to keep up on the maintenance,
a poorly maintained engine suffers economy loss.

It is possible, but unusual.
I wouldn't hedge too many bets on it, however every car has an optimum
cruising range and the perfect range usually falls within 1-2 mph.

On the flip side, there is also a human tendency to keep doing something considered a 'sacrifice', because there is a feeling that it MUST have SOME benefit. For instance, MANY people believe that certain foods are healthy just because they are nasty tasting (when they are, in fact, FAR less healthy than they believe). This is why experimentation (rather than driving at a speed that OTHERS tell you is most efficient) is the ONLY way to find that optimum speed.

Or my wife buying into the whole ORGANIC CRAZE. She has issues with our kids eating non-organic grilled chicken with non-organic rice and non-organic vegetables but no issues with them stuffing their faces with organic version of Oreo's.

Anyway what rpm do you sit at going 65mph?

like the other guys are saying go with what works. my old cressida had its best FE going at 140km/h....fast journey:)

best mpgs I can get is around 50mpg in 5th gear going about 30mph. Its not such a bad trade off to get 43mpg when going 60mph though (based on scangauge)

I've measured 43 mpg cruise control at 65mph.

I've done 70+ mpg highway by pulsing and gliding. That's nothing to sneeze at.