How could I lose 10 mpg in a week of BETTER driving?!

[Atheria]

Hi Darrell. I can only barely stand going 65 when the limit on many highways here is 75. I can't handle driving even more like an old lady. :-)

Atheria

[gone-ot]

Which is more important? Milage or image?

[Diesel_Dave]

My truck doesn't display instantaneous FE, just trip. Maybe it's just that that is what I'm used to, but anytime when I've driven a vehicle with an instantaneous readout, I haven't found it very useful. It just fluctuates too much. Plus, keep in mind that it's the TRIP fuel economy that's imprtant to you anyway--not the instantaneous.

55-60 is nearly every car's sweet spot.

I can tell you my truck's "sweet spot" is WAY below 55-60 mph. My perspective is probably different than most because I drive a vehicle with a massively oversized engine with gobs of low-end torque, but, IMO the "sweet spot" for vehicles with manual transmissions is about as slow as you can tolerate driving.

[MetroMPG]

Originally Posted by SentraSE-R

55-60 is nearly every car's sweet spot.

Graph after graph after graph disputes that... unless you're talking about km/h

http://ecomodder.com/forum/showthrea...you-15182.html

[Frank Lee]

In the absence of a BSFC chart, I like the ol' 1000-1200 ft/mn piston speed guide; on the Coupe that range is 50-60 mph, so I often hold 50.

[razor02097]

Originally Posted by MetroMPG

Graph after graph after graph disputes that... unless you're talking about km/h

http://ecomodder.com/forum/showthrea...you-15182.html

+1 My vehicle likes 35-40mph. I don't have to P&G to get great FE at those speeds.

My Jeep's sweet spot is about 50mph that is when the stupid torque converter finally locks up.

[XYZ]

Originally Posted by alvaro84

What do you mean by sweet spot? Because the highest steady speed FE is almost always at the very bottom of the top gear. In case of my Yaris (which is a rather small car with a rather small engine and short gears, of course), it's like 30 mph, or even lower. You can't always go at 30, of course...

What you said is true in principle. Except that on most cars with an automatic tranny it will be when the car goes into TC lockup mode, which can be as high as 45 MPH. Obviously on a manual it will be the lowest speed you can sustain while in the highest gear. And it won't be 30 - but it need not be 55, either. However, you can go somewhat faster without sacrificing FE to speed, which is why the 55-60 MPH suggested is a workable compromise.

But real life often requires practicality, as opposed to the extraordinary lengths some ecomodders will go to save fuel. What's more important? Saving time and getting to your destination somewhat faster and not annoying the drivers behind you? Or making high fuel economy an obsession?

[Frank Lee]

#$^& the drivers behind, whenever they can pass.

[alvaro84]

This is why I said you can't always go that slow. But my commute is a rather short trip (~15mi one way) and my best route mostly consists of deserted back roads So I can really expend a few minutes a day on a hobby, which happens to be hypermiling

But I wouldn't go that slow on busy main roads or longer trips. I'm also faster with Teresa, because her 5th gear is practically unusable below ~45mph and she rewards P&G over 45 with a few more mpg. Even 75-mph pulses aren't heresy with her.

It depends on many things.

[Diesel_Dave]

Don't get me wrong, I'm not advocating going 20 mph on the freeway. But if we're talking strictly what's best for FE (with a manual tranny) slower is almost always better.