Saturday, June 11, 2016

Land Rover LR4 Ground Clearance

I decided to measure the ground clearance of my 2015 LR4.  I've always wondered what the real clearance was under some specific locations.  This was the best way to find out.

Suspension Heights Measured:
Measurements were made at 4 different suspension height settings: normal, off-road, extended, and super-extended.  OK, it's not officially named "super-extended."   I just call it that.  That highest setting doesn't have a name in the manual.  It's described on page 99 of the 2015 LR4 Owners Handbook as providing "additional lifting."

Normal Height:
Everybody knows what this is.

Off-Road Height:
Each time I raised the suspension, I drove the car a couple feet, then backed up to where I started.  I hoped this would allow the suspension to settle and provide better measurements.

Extended Mode:
I forced the car into Extended Mode by lowering it from Off-Road Height onto a 10 inch tall block of wood at the lateral frame member.  This makes the car think it's high-centered and it raises it to Extended Mode.  Here's that wood block under the car in Off-Road height.


After raising to Extended Mode...


In Extended Mode the dash instructs you how to raise it a bit further.



Super-Extended Mode: (not the official name)
As the handbook explains, after you are in Extended Mode, then you can gain "additional lifting" by pressing the UP ARROW and holding it for more than 3 seconds, while pressing on the brake pedal.  The control indicators for this highest of suspension settings remain unchanged from Extended Mode.  Unlike Extended Mode, it no longer tells you how to raise it a bit more.

Locations Where Clearance Was Measured:
Measurements were taken at several locations on the undercarriage.  I picked these locations because they appeared to hang down the lowest.
  • front skid plate
  • second skid plate (I think it covers the oil pan, but i'm guessing)
  • front lower control arms
  • frame cross member
  • fuel tank skid plate (lowest point near front edge)
  • front edge of muffler (it looks like a muffler, maybe it's the cat)
  • exhaust pipe in front of spare tire (hangs a bit lower than the plastic guard around the spare)
  • rear lower control arms

Conditions:
I made the measurements in my garage.  The concrete floor is reasonably level.  I used a string of LED lights to illuminate the underside of the car.  The car was dirty, so I apologize for the grime.  The car was empty of gear and had a half-tank of gas.  My tires are Cooper Zeon LTZ 255/55R19 with about 10k miles of wear on them.  At the time of the measurements, the tires were inflated to 36/43 psi (F/R).


Photos:
Here are some photos I took during the measurements.  I won't include every photo, but I will include at least 1 photo per measurement location.  My tape measure is 3 inches tall and so 3 inches is added to each visible measurement for the total height.

Front Skid Plate:


Second Skid Plate:


Front Lower Control Arm:


Frame Cross-Member:


Fuel Tank Skid Plate:


Front Edge of Muffler:



Exhaust Pipe in Front of Spare Tire:


Rear Lower Control Arm:


Ground Clearance Values:
Here is a table of the measurements I made.  All measurements are in inches.  


Conclusion:
I learned a lot from this exercise.  I was unable to take decent photos of the entire undercarriage.  I wanted that so I could annotate a photo showing the measurement locations and the clearance at a given suspension height.  The LED lights didn't help much.  I could have strung them directly below the car, but then they'd mess up the camera's aperture settings.

Sorry for the sloppy procedures and methods.  The measurements weren't super precise, due to several factors, but they still give me some idea of what hangs the lowest and will likely hit a boulder first.  Knowing where the low points are can also help me to pick the best line when ground clearance is most limited.

I hope this is somewhat useful to other LR4 owners.  I'm curious to know how reproducible the measurements are.  Maybe there's variability between cars due to slight differences in suspension height sensor calibration, etc.  

Maybe next I'll try measuring the approach and departure angles at each suspension height setting.

2 comments:

Thomas Davenport said...

Michael, thanks for the post. Very interesting. I was wondering under what circumstances the ride height resets. Does it drop after hitting a certain speed or does it hold extended mode until you turn it off?

Michael said...

Thomas,
Sorry for the delay. I've been traveling. The suspension will remain at off-road height as long as you stay below 30 mph. In practice, if I get up to 28 mph then a chime sounds and the dashboard display warns me that the suspension will lower if I do not slow down. This is one of the reasons I no longer own a Land Rover. I need a suspension that does not change height on its own.