Your eyes lies about 50% of the time?

[Vekke]

Hi,

yesterday I was travelling with a truck and I learned something new. Truck driver had a navigator which showed height from sealevel. About 50% of the time if you looked forward in a small "downhill" and started to look the navigator and it told that it was infact a uphill 1 meter up every 50 meters or so. So you cannot tell with your eye is it really or uphill or not.

Problem is that you have been in a deep uphill and it just get smaller uphill. Your eye says now it turned to downhill but its just not so deep anymore.

So get a navigator or some other device that shows is it really a downhill or not. I have wondered many time that why does not my roll in this downhill. It must have been uphill then.

I started to wonder what else you could use to tell which way you are going?

Redirect Notice

Glue that to your sidewindow etc and that might work. I will give it a shot .

[SentraSE-R]

I set my car's cruise control, and wait until impg reaches 40 mpg. Then I know I'm on a slight downhill.

[California98Civic]

Originally Posted by Vekke

Redirect Notice

Glue that to your sidewindow etc and that might work. I will give it a shot .

Or attach two of these in a "T" formation on the center console, using a good 4' level to set them correctly? But why do you need to know so precisely?

[jakobnev]

Originally Posted by Vekke

Redirect Notice

Glue that to your sidewindow etc and that might work. I will give it a shot .

That isn't going to work tho since gravity and acceleration are indistinguishable.

[Vekke]

On my lupo its not so precise but on that 45 tonn truck it was a no go in a sligtest uphill. That truck was lacking also instant fuel consumtion gauge. So this in not so much for me but to my customers. That navi which he used cost 600 dollars so its quite expensive just to test the hypermiling in a truck...

If you drive steady speed it should work? So you check that gauge before you start doing P&G. Once you know that it is actually downhill you see when the road changes again its way and need to check gauge again.

[tinduck]

Difficult.

Bubble levels won't work when accelerating (negative or positive).

Eyeball MK I deceives you (or your brain does).

FE meter cannot distinguish uphill from headwind.

You have to integrate any input you can get about wind and road condition to reach a decision... and you may still be wrong.

so long,

tinduck

[FXSTi]

I'm glad you posted this. I have a few spots where I just can't tell if they are up or down. I was beginning to think that it was just me.

I have gone over some common routes using Google Earth. It shows at the bottom of the screen the altitude where your mouse is.

Kirk

[NachtRitter]

I've experience the same thing when bicycling... even to the point where I've gotten off the bicycle to check if I have low tire pressure or a dragging brake... I finally realize I'm actually going uphill...

[wdb]

Cyclists call them "false flats". The eyes tell you the road is level, but the legs tell a different story.

[euromodder]

Usually, I'll have my GPS set so it shows height.
While the absolute value usually isn't entirely correct, the relative changes are obvious.

I have a few very deceiving flats in my commute that, well, aren't really flats at all.


I might try a bubble level - cheap & easy when not using the GPS.