Outdoor Lover wrote:There is 2" difference in the "Running Ground Clearance" between the two. The Cherokee was 8.6 and the Escape is 8.4.
Did you mean to say 2/10's of an inch? If my math is correct 8.6 - 8.4 = .2
But no matter, there's quite a bit more to it than 'running ground clearance'. Let's start with the basics:
Ground Clearance / Ride Height – The measurement from the ground to the lowest point on the underside of the vehicle. This amount would represent the clearance the vehicle has without scraping the underside of the vehicle. In most cases the axle housing or part of the exhaust system will be the lowest part.
So with your Escape on a flat surface road, the lowest part of the vehicle will contact any obstacle over 8.4". However, if you take a look under your car, take note of just what is the lowest part and where it is. If you remember that just make sure to drive to one side or the other to avoid making contact.
Angle of Approach - The angle measured by drawing a straight line from the front of the front tire to the bottom of the front bumper. It represents the angle of inclination that a vehicle can tackle while climbing a slope without hitting or scraping the front bumper.
On my Samurai the front spring shackles stick out just past that imaginary line so they are the limiting factor.
Angle of Departure - The angle measured by drawing a straight line from the back of the rear tire to the bottom of the rear bumper. It represents the angle of declination that a vehicle can tackle while descending a slope without scraping the rear bumper.
This is much more of a critical issue for my Pathfinder than my Samurai because the long rear overhang of the Pathfinder. If there is a deep dip, the receiver hitch will drag... too much so and the rear wheels would lose traction.
Ramp Over Angle - This is a measure of a vehicle's ability to drive over a sharp ridge or ramp without touching its underside. The "included" angle measures the angle inside the ramp; the "exluded" angle measures the combined angles outside the ramp to the horizontal. The larger the angle the steeper peak the vehicle can travel over. Violating this angle leads to the most likely cause of costly damage to your vehicle.A short-wheelbase vehicle with a high ground clearance and large tires will have the best (highest) ramp over angle.
Although my Pathfinder has the tallest tires that will fit in the wheel-wells and a higher ground clearance, the long wheelbase reduces the ramp over angle. On the other hand, my Samurai has such a short wheelbase that it has a much greater angle. However, with the aluminum transfer case being in the center of the vehicle (the tip of the angle) if I hit anything it's very likely to cost $$. Due to that the next item on my list is a transfer case skid plate... coming soon.
So... back to the original question about high clearance. When I describe a road (or pack trail as many of my adventures seem to be on) and I mention 4WD and high clearance, I consider them as two completely separate entities:
Four Wheel Drive:
The road has steep hills and/or with loose/wet/slick/muddy terrain and/or with deep ruts that may cause a wheel to be off the ground. In these case 4 wheels working together is critical. While front wheel drive may work great in snow, when you're climbing a steep hill on loose or slick terrain most of the weight is on the back so the front end will be light and traction will be limited.
High Clearance:
1. The road has many obstacles that will require more static clearance.
2. The road has steep dips and/or peaks which will test all the angles, approach, ramp over and departure.
What is the quickest way to gain clearance? Yep, taller tires.
But again there are things to consider:
Tire clearance in the wheel-well under all conditions, full spring compression as well as when front wheels are turned.
Tire diameter change will change your speedometer reading... taller tire will rotate slower so you will be going faster than it reads. And due to that fact, the computer will not be getting accurate readings which could affect shift points if you have an automatic transmission.
Tire diameter also affects the effective gear ratio of the vehicle... a taller tire will reduce your available torque, and even with the calculation corrected you will not get quite the same fuel economy... and I don't mean making it better.
Oops, there's one other thing I may mention a road may require...
a very capable 4x4
This usually means the terrain is very steep and traction can be very tentative, requiring a
differential locker which effectively locks both wheels on one axle together. I'm not going into it any deeper at this point, but suffice to say with your Escape, if you get one front wheel in the air, at that moment you have ZERO-wheel drive. There are many 4WD vehicles out there that will yield the same 0WD with one wheel off the ground.
Oh yeah, one last and
most important thing... The most capable vehicle in the world is no good without a
capable and
confident driver. And how does one become capable and confident?
1. Practice, practice, practice, and more practice!
2. Throw in a dose of tips from off-road veterans
3. Imitate others... as in following someone with more experience than you and watching the lines they take. In the just under a year since I got my Samurai I've used 1, 2, 3, 1, 1, 1, 1, 1, 1, 1, 1 and continue with more practice taking on bigger obstacles every day.
Yesterday I finally tried to drive up and over an obstacle I had never tried before, basically a 4 foot wall.... Two attempts and I realized without a spotter it just wasn't going to happen... unless and until I get the last two items on my list for the Samurai... the transfer case skid-plate and front locker. Soon... if the gas prices don't break me
P235/70R16 I believe the load rating is E2
