How steep is that hill, really?

[xirdneh]

Recently I was driving the Tercel up a steep hill and got to wondering “What is the angle of a steep hill?” Some hills have a sign stating the grade, such as “14% Grade” but what angle is that? One of the steepest hills around here is Anderson Hill and it is marked as a 14% grade. That turns out to be 14% of 45 degrees which is an angle of 6.3 degrees. 6.3 degrees, Really! That does not seem like much. Most people I have asked thought Anderson Hill was around 30 degrees, myself included. So I grabbed the angle gauge out of the workshop and drove to the hill. Sure enough the needle reached about 7 degrees. I have tested several other local hills and the steepest found so far was short hill at 12 degrees which is about a 26% grade. Draw a line on a piece of paper at 12 degrees. It just does not look formidable but the Tercel has to work to climb it.

[ARCHINSTL]

Now, THIS is a steep Tercel hill:
Tom M.

[dlb]

i've always wondered what the hell those percentages meant. thanks!

[Petros]

The "percent grade" is a ratio of rise over run. An 8 percent grade means you will rise 8 feet for every hundred of travel. It is the same as the "tangent" function (x/y). So a 100 percent grade is 45 degrees (rise and run are the same). So a 12 percent grade is Tan-1 (.14)= 7.97 degrees. a 50 percent grade is 26.6 degree. It is rare that large hwys ever get over about 8 percent (4.7 deg), and local surface roads over about 20 percent (11.3 deg). Most interstates have warnings for 6 percent for large trucks. There is no easy conversion in your head other than to just think of it as feet rise over 100 feet of run.

Since my current work sometimes requires me to specify grades I am very familiar with it. It has been my observation that most 2wd cars can stop and start on a 16 percent grade, and make it up a 20 percent grade if kept moving. About 30 percent is the steepest a good 4wd can climb off-road. Most people feel comfortable walking up a 30 percent grade, and 100 percent feels like a cliff (most will want to put their hands down grab plants for balance and assistance.)

[danzo]

That is strange, I just ass-umed it meant 14 degrees from horizontal. Maybe we should start a "knarly hill club" on this site to see who can climb the steepest slope and post videos of it. It would be alot of fun, but I can see potential for disaster. I just spoke to my attorney and therefore I must respectfully claim no responsibility on this matter.

BTW years ago I remember seeing a TV show featuring a hill that was a total optical (optional?) illusion. If you parked your car facing up the slope and put 'er in neutral the car would roll forwards uphill. Just curious - does anyone know where this is? It seems it was here in the States.

[ARCHINSTL]

BTW years ago I remember seeing a TV show featuring a hill that was a total optical (optional?) illusion. If you parked your car facing up the slope and put 'er in neutral the car would roll forwards uphill. Just curious - does anyone know where this is? It seems it was here in the States.

They are called "gravity hills" or "magnetic hills" and are all around.
More than you ever wanted to know about them:
Wikipedia list of worldwide examples: http://en.wikipedia.org/wiki/List_of_magnetic_hills and
http://userpages.umbc.edu/~frizzell/gravhills.html and http://paranormal.about.com/library/wee ... 20301a.htm

One of my daughters saw the hill in PA and swore it was true (even though she knew it was not).
Tom M.

[xirdneh]

Found a road in Bremerton, Wa. today that's 15 degrees (Farragut Ave)(about 33% grade)
would not want to start from a stop on it while going uphill
so when i stopped to measure the angle the car was pointing downhill

[tercel4wdrules]

Down here in Silverlake, CA we have Fargo St which is a 30% grade street. I have been up that one with 4 passengers onboard with no problems other than the tires having a tendency to break loose in FWD, so I had to modulate the accelerator. There's another road I attempted to go up and failed, it was steeper than 30% and I was almost at the top when it would just bog and want to stall out in 4WD. I had to carefully reverse and slip into a driveway so I would have the front-end pointing down on the descent, but my friend thought I was going to roll it over, but I was positive I wouldn't.

I also tried to go a rather steep dirt hill out in the desert and just barely made it. It was scary since if I didn't, the trip back down wasn't going to be very fun. It almost ran out of power 3/4ths of the way up, but then all of a sudden it started accelerating again and we made it. Whew, a little too close for comfort.

[xirdneh]

it was steeper than 30% and I was almost at the top when it would just bog and want to stall out in 4WD. I had to carefully reverse and slip into a driveway so I would have the front-end pointing down on the descent, but my friend thought I was going to roll it over, but I was positive I wouldn't.

i watched a friend try to drive his Toyota Landcruiser (the short stubby one) up a steep logging road
when he lost traction he tried to back up and turn Around
that did not go to well
sideways on the hill with the back up turning momentum
i watched him begin to tip in slow motion
then he rolled several times
his wife and i were standing at the bottom and she began to scream
he was lucky he had his seatbelt on (the top was off and it had a roll bar)
he was also lucky it angled off the road into the clear cut or it would have rolled way way more times
he landed right side up with a few new dents
and drove it home

[tercel4wdrules]

Sometimes you do things you regret later (usually led on by others). I let my friend drive my other T4WD up that hill and he failed to get it past the beginning, it was just spinning tires. There were cars parked up there (non-4WD) and I wondered how the heck they got them there . It's advised not to travel sideways on a hill, but it seemed that rolling back down in reverse wasn't going to be very pretty either, so I just took my chances and backed up into a spot on a hill where I thought my chances of saving my tootsie was greater. It worked this time, but I'll be thinking twice before going up a hill which I don't feel comfortable with.

[Barto]

Here is my old rock crawler click on picture for link. Definitely not the steepest i've gone up either but still a good climb
I'm looking for some of the pictures of the tercel stuff i've climbed up too.

[takza]

I'd sooner take a chance turning around on a hill...as opposed to an uncontrolled bassackwards slide down.

[dlb]

bart, that was still pretty dope. have you been to the tough truck competition in langford? it was awesome, hilarious, and horrifying all at once.

btw, how'd the job interview go? i cleaned and painted that hood up, it's just going to be my interim hood while i install the scoop on the green one. looks rally now.

[splatterdog]

Never had to resort to it, but I heard whipping a reverse shitty is the best strategy for a failed hill climb. Crank the wheels and juice it in reverse and whip the front end around to point it downhill.

[dlb]

a reverse shitty

SD, you definitely have the title for best lingo. you're full of gems!