2018 4runner suspension upgrade

Great explanation.

 

This was well written but absolutely not all true. You DO increase clearance when installing a lift. Your “static height” as you called it has moved up by the amount of the lift. As for the range of motion - your statements are true if one were to remain with stock suspension components. Or, if we were to use a spacer - it would have the same effect. However, most kits come with springs and shocks that were properly matched up. Those shocks will have (among other differences) longer range of travel.
installing a 3” lift will, in fact, increase my ground clearance by 3”. Adding a larger tire, will increase my clearance some more. So, suspension lift + tire lift = total lift. You can measure from the frame to the ground or from the fender to the ground and you will see the effect. What you’re talking about is range of travel...


After re-reading your post, it seems that you were elaborating on tire clearance. In which case it’s still partially true and a lift will have an impact on clearances. As you stated, if the static center is moved higher (your wheels sit further down from the body when lifted) you will still have longer distance of upwards travel for the wheel (clearance) before it rubs by roughly the same amount as lift. In reality most lifts come with stiffer springs, which further decreases the compression and will allow you to traverse significantly larger obstacles before the tire is tucked enough to cause rub.

 

Static height (not my term, that’s literally what it’s called) being higher does not mean extra clearance... for reasons I just explained. Static height just changes the scenario of when the tire rubs, that’s not the same as adding clearing. Extra downward travel isn’t helping you clear a tire. Lifting it 3” doesn’t give you 3 extra inches of ground clearance, it doesn’t give you any extra ground clearance. You can increase approach angle, break over angle, and departure angles with a lift, but your ground clearance is the lowest point to the ground, and that will always be the rear diff, that’s not effected by suspension.

 

When referring to ground clearance it is generally assumed that frame/body would be a reference point. By your logic, only tire or wheel changes would change ground clearance - if we use the diff as a reference point.
So your approach and departure angles, break over angles (as you said) are improved with a lift. Ability to climb over taller obstacles is increased off-road ability.
Easy proof? You take a stock t4r and I’ll bring my lifted one on a trail - and see how we fare. See who takes body damage and bottoms out the suspension. And see who can get over rougher terrain. It’ll be the guy with a lift and the increased ground clearance

 

You’re correct - the body will have more clearance, I never said that wasn’t beneficial to off-roading. And yes, the only way to increase the actual ground clearance is an increase in tire size.

Maybe you assume ground clearance to be some random arbitrary point of your choosing, however ground clearance is and always will be, the lowest hanging part of the vehicle to the ground.